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Genome-guided stage- and tissue-resolved transcriptome analysis of Serrodes campana identifies sex-biased antennal expression and candidate chemosensory-related genes.

Serrodes campana is an erebid moth of ecological and forestry relevance; its larvae are mainly associated with the soapberry tree, Sapindus mukorossi, whereas adults exhibit fruit-piercing behavior. However, stage- and tissue-resolved transcriptomic resources for this species remain limited. Here, using a chromosome-level reference genome, we performed a genome-guided transcriptome analysis of S. campana based on 12 RNA-seq libraries representing major developmental stages and key adult tissues. Global transcriptomic analyses revealed pronounced transcriptional differentiation across developmental stages and tissue types. Tissue-enriched gene sets and functional enrichment analyses identified distinct molecular signatures associated with developmental, sensory, and pheromone-associated tissues. Comparative analysis of female and male antennae further revealed sex-biased expression of several candidate chemosensory-related genes. Among 153 curated chemosensory-related candidate genes, most odorant receptor genes showed strong antennal enrichment, whereas other major chemosensory gene families displayed broader but still tissue-preferential expression patterns. In addition, an exploratory comparison of female terminal abdominal gland tissue and male terminal abdominal coremata revealed divergent expression profiles and highlighted candidate genes potentially associated with pheromone-related physiology, reproduction, and tissue-specific signaling. Together, this study provides the first genome-guided stage- and tissue-resolved transcriptomic resource for S. campana and offers a useful foundation for future studies of chemosensory detection, sex-biased gene expression, and pheromone-associated biology in this species.

Animals↗

Somatic isoform of angiotensin I-converting enzyme in the pathology of testicular germ cell tumors.

Retained fetal expression of angiotensin I-converting enzyme (ACE, CD143) has recently been shown in intratubular germ cell neoplasms (IGCN) and invasive germ cell tumors (GCT), suggesting the somatic isoform (sACE) as a characteristic component of neoplastic germ cells. We analyzed the distribution of sACE in 159 testicular GCT, including 87 IGCN. sACE protein was determined by immunohistochemistry (MAb CG2) on routinely formalin-fixed and paraffin-embedded tissue sections, supplemented by mRNA expression analysis using in situ hybridization. These data were compared with those obtained by germ cell/placental alkaline phosphatases (PIAP; MAbs PL8-F6 and 8A9) employing an uniform score system for the evaluation of immunoreactivity (IRS; possible values from 0 to 12). Expression of sACE and PIAP was found in all 87 analyzed IGCN (IRS > 4, median IRS of 12). Heterogeneous staining patterns were not related to the type of adjacent GCT but correlated with low expression in adjacent seminomas (P =.032 for sACE; P =.005 for PIAP). Both sACE and PIAP often showed a decreased and more heterogeneous but still moderate expression in 91 classic seminomas (median IRS of 8) and were completely absent in tumor cells of spermatocytic seminomas. Despite all similarities, we found sACE and PIAP differently regulated during GCT progression. This was documented by a well-preserved expression of either sACE or PIAP or both in all classic seminomas, low PIAP immunoreactivity in metastasis of seminomas, and completely diverging expression patterns in nonseminomatous GCT. Our findings underline the close molecular relationship between IGCN and seminoma, and suggest sACE as an appropriate marker for seminomatous differentiated tumors. HUM PATHOL 31:1466-1476.

Adolescent↗

Expression of early growth response genes in human prostate cancer.

Early growth-response (EGR) genes are nuclear transcription factors that are implicated in regulating cell proliferation. Because these genes show divergent expression in various human tumors, we sought to determine their expression in nonmalignant and malignant prostate tissues. Total RNA extracted from prostate tissues was probed with EGR-1, EGR-2, and EGR-alpha cDNA for Northern blots and digoxigenin-labeled cRNA for in situ hybridization. Both Northern blot and in situ hybridization analyses demonstrated increased EGR-1, but not EGR-2 or EGR-alpha expression, in malignant prostate tissue as compared with weak expression in nonmalignant tissue. EGR-1 mRNA was quantified in 96 prostate specimens (86 adenocarcinomas representing different Gleason scores and 10 benign tissues showing no histological manifestation of benign prostatic hypertrophy) using in situ hybridization with an 35S-labeled cRNA probe. EGR-1 mRNA was expressed at significantly higher levels in cancer than in normal prostate (P < 0.001). In cancer with Gleason scores 8-10, the expression of EGR-1 was higher compared with those of lower Gleason scores (P < 0.005). Immunohistochemical staining showed predominately basal cell nuclear EGR-1 protein in prostatic acini. Nuclear staining was weak in nonmalignant tissues, more intense in moderately differentiated carcinoma, and most intense in poorly differentiated carcinoma. These results show that EGR-1 is overexpressed in prostate cancer and suggest a role for EGR-1 in prostate cancer growth.

Adenocarcinoma↗

Developmental, stage-specific, and hormonally regulated expression of growth hormone secretagogue receptor messenger RNA in rat testis.

Recent evidence from our research suggested the direct role of ghrelin in the control of testicular function. However, the pattern of expression and hormonal regulation of the gene encoding its cognate receptor (i.e., the growth hormone-secretagogue receptor [GHS-R]) in the male gonad remains to be fully elucidated. In this paper, overall expression of GHS-R mRNA in rat testis was compared with that of the functional receptor form, namely GHS-R type 1a, in different developmental and experimental settings. In addition, cellular distribution of GHS-R within adult testis tissue was assessed. Our analyses demonstrated persistent expression of the GHS-R gene in rat testis throughout postnatal development. In contrast, testicular expression of GHS-R type 1a mRNA remained undetectable before puberty and sharply increased thereafter. In adult testis, GHS-R1a mRNA expression presented a scattered pattern of cellular distribution, including Sertoli and Leydig cells that also showed specific GHS-R1a immunoreactivity. Expression of total GHS-R and specific GHS-R1a mRNAs was detected in isolated seminiferous tubule preparations, with varying levels throughout the defined stages of the spermatogenic cycle. In addition, testicular expression of total GHS-R and GHS-R1a mRNAs was up-regulated by exposure to ghrelin in vitro and after stimulation with FSH in vivo. In conclusion, our data demonstrate that expression of the GHS-R gene in rat testis takes place in a developmental, stage-specific, and hormonally regulated manner. Divergent expression of total GHS-R and type 1a specific mRNAs was detected at certain stages of postnatal development and spermatogenic cycle, thus raising the possibility that, in addition to net changes in GHS-R gene expression, the balance between receptor subtypes may represent a novel mechanism for the tuning of ghrelin sensitivity in rat testis.

Animals↗

Mesoderm-specific expression of the divergent homeobox gene Hlx during murine embryogenesis.

We have determined the expression pattern of the divergent homeobox gene Hlx during post-implantation mouse development, utilizing in situ hybridization. Expression was mesoderm-specific and occurred in a complex tissue distribution. Transcripts were first detected at 9.5 days post coitum (p.c.) in splanchnic mesoderm of the midgut and hindgut region, then during organogenesis, prominently in mesenchyme of the developing liver, gall bladder, and intestines, as well as their mesenteric tissues. In the foregut, lung mesenchyme became positive from 10.5 days p.c. Hlx transcripts were also detected in a subset of skeletal myogenic cells: those within branchial arches from 9.5 days p.c. and within limb buds from 12 days p.c. Hlx was not expressed in myogenic cells which are derived from the myotome and populate the trunk. However, from 10 days p.c., expression was seen in a region of the sclerotome immediately adjacent to the myotome and corresponding to precursors of the ribs and vertebral neural arches. In the anterior-posterior aspect of the developing sclerotome, Hlx expression was out of register with original segmental boundaries (intersomitic fissures), a pattern consistent with a classical hypothesis that the developing vertebral column undergoes resegmentation. Hlx expression was also observed in vibrissae, pericardium, snout mesenchyme, and meningeal epithelium. Overall, expression of Hlx in only a subset of individual lineage progenitors and at know sites of inductive tissue interactions, suggests that the gene regulates local patterning or growth through cell:cell signalling at those embryonic sites.

Animals↗

Regulated expression of putative membrane progestin receptor homologues in human endometrium and gestational tissues.

Rapid non-genomic actions of progesterone are implicated in many aspects of female reproduction. Recently, three human homologues of the fish membrane progestin receptor (mPR) have been identified. We combined bioinformatic analysis with expression profiling to define further the role of these mPRs in human reproductive tissues. Sequence analysis confirmed that the mPRs belong to a larger, highly conserved family of proteins, termed 'progestin and adiponectin receptors' (PAQRs). A comparison of the expression of mPR transcripts with that of two related PAQR family members, PAQRIII and PAQRIX, in cycling endometrium and pregnancy tissues revealed markedly divergent expression levels and profiles. For instance, endometrial expression of mPRalpha and gamma and PAQRIX was cycle-dependent whereas the onset of parturition was associated with a marked reduction in myometrial mPRalpha and beta transcripts. Interestingly, mPRalpha and PAQRIX were most highly expressed in the placenta, and the tissue expression levels of both genes correlated inversely with that of the nuclear PR. Phylogenetic analysis demonstrated that PAQRIX belongs to the mPR subgroup of proteins. We also validated a polyclonal antibody raised against the carboxy-terminus of human mPRalpha. Immunohistochemical analysis demonstrated more intense immunoreactivity in placental syncytiotrophoblasts than in endometrial glands or stroma. The data suggest important functional roles for mPRalpha, and possibly PAQRIX, in specific reproductive tissues, particularly those that express low levels of nuclear PR.

Adult↗

Inosine-5'-monophosphate dehydrogenase: regulation of expression and role in cellular proliferation and T lymphocyte activation.

Guanine nucleotide synthesis is essential for the maintenance of normal cell growth and function, as well as for cellular transformation and immune responses. The expression of two genes encoding human inosine-5'-monophosphate dehyrogenase (IMPDH) type I and type II results in the translation of catalytically indistinguishable enzymes that control the rate-limiting step in the de novo synthesis of guanine nucleotides. Cellular IMPDH activity is increased more than 10-fold in activated peripheral blood T lymphocytes and is attributable to the increased expression of both the type I and type II enzymes. In contrast, abrogation of cellular IMPDH activity by selective inhibitors prevents T lymphocyte activation and establishes a requirement for elevated IMPDH activity in T lymphocytic responses. In order to assess the molecular mechanisms governing the expression of the IMPDH type I and type II genes in resting and activated peripheral blood T lymphocytes, we have cloned the human IMPDH type I and type II genes and characterized their genomic organization and their respective 5'-flanking regions. Both genes contain 14 highly conserved exons that vary in size from 49 to 207 base pairs. However, the intron structures are completely divergent, resulting in disparities in gene length (18 kilobases for type I and 5.8 kilobases for type II). In addition, the 5'-regulatory sequences are highly divergent; expression of the IMPDH type I gene is controlled by three distinct promoters in a tissue specific manner while the type II gene is regulated by a single promoter and closely flanked in the 5' region by a gene of unknown function. The conservation of the IMPDH type I and type II coding sequence in the presence of highly divergent 5'-regulatory sequences points to a multifactorial control of enzyme expression and suggests that tissue-specific and/or developmentally specific regulation of expression may be important. Delineation of these regulatory mechanisms will aid in the elucidation of the signaling events that ultimately lead to the synthesis of guanine nucleotides required for cellular entry into S phase and the initiation of DNA replication.

Amino Acid Sequence↗

Regulatory elements involved in Drosophila Adh gene expression are conserved in divergent species and separate elements mediate expression in different tissues.

Alcohol dehydrogenase (ADH) is expressed in a complex temporal and spatial pattern from tandem promoters (proximal and distal) in Drosophila melanogaster, and from two closely linked genes (Adh-1 and Adh-2) in D. mulleri. The expression patterns of Adh-1 and the proximal promoter, and Adh-2 and the distal promoter are similar, but not identical. We show that the mulleri Adh genes are appropriately expressed when introduced into the melanogaster genome, indicating that the cis- and trans-acting elements which regulate the corresponding promoters are functionally equivalent in the two species. By analyzing the expression of in vitro generated mutants of the mulleri Adh locus, we define at least three regulatory regions of the mulleri Adh genes and show that different control elements mediate the expression of Adh in different tissues.

Alcohol Dehydrogenase↗

Variable expression of podocyte-related markers in the glomeruloid bodies in Wilms tumor.

Several podocyte-related markers are organized to express in glomerular differentiation. However, whether expression of them is virtually synchronized and a reliable indicator of the state of differentiation is unknown. The present study investigated, by immunohistochemistry, the divergent expression of several podocyte markers in the improperly differentiated glomeruloid bodies from four cases of Wilms tumors. The glomeruloid bodies were classified into immature (IGB) or mature forms (MGB) based on morphology and epithelial features. Podocytes in IGB expressed WT1, synaptopodin, podocalyxin, and nephrin, and their expression was stronger in MGB. In contrast, Pax2 was strong in IGB and diminished in MGB. p27 was first expressed in MGB. The expression pattern in each molecule mimics normal glomerulogenesis. Podocytes in MGB showed persistent expression of bcl-2 and cytokeratin with synaptopodin, podocalyxin, and nephrin by serial section, a finding unusual for normal glomerulogenesis. Moreover, parietal cells in MGB also occasionally expressed these podocyte markers. The ultrastructure revealed that podocytes in MGB showed tight junctions without foot process formations, which indicated incomplete differentiation. These results suggest that a set of podocyte differentiation markers are occasionally diversely expressed, and raise the possibility that expression of these markers is insufficient to determine the state of terminal differentiation in podocytes.

Biomarkers, Tumor↗

Differential expressions of cyclin-dependent kinase inhibitors (p27 and p21) and their relation to p53 and Ki-67 in oral squamous tumorigenesis.

The cyclin-dependent kinase inhibitors p27Kip1 and p21WAF1/Cip1 play important roles in cell-cycle regulation. Although alterations of these genes have been linked to tumorigenesis of several human carcinomas, their involvement in head and neck squamous tumorigenesis is rarely investigated. To determine the role of these genes in the evolution of squamous carcinoma of the head and neck we evaluated their protein expression by immunohistochemistry in non-dysplastic squamous epithelium, premalignant lesions and oral squamous carcinomas. The p53 gene and Ki-67 expressions were correlated with traditional clinicopathologic variables. Our study shows that in histologically non-dysplastic squamous epithelium, p27 expression was noted mainly in superficial differentiated cells, whereas p21, p53 and Ki-67 staining was observed in basal and suprabasal cells. In dysplasia, divergent expression between p27 and p21 was observed: p27 precipitously decreased and p21, p53, and Ki-67 increased with histologic progression. In squamous carcinomas, p27 was mainly expressed in well differentiated tumor cell nests, while the expressions of p21, p53, and Ki-67 were variable in the poorly differentiated tumor areas. A significant inverse relationship between p27 expression and those of p21, p53, and Ki-67 was observed, but no significant association between any of these markers and clinicopathologic factors was noted in this cohort. Our study indicates that: i) down-regulation of p27 and up-regulation of p21 are associated with early progression of HNSC, ii) p21 expression correlates positively with proliferation while p27 correlates positively with cell differentiation and iii) concurrent p27 and p21 expression analysis may allow for better assessment of HNSC progression.

Adolescent↗

MDS1/EVI1 enhances TGF-beta1 signaling and strengthens its growth-inhibitory effect but the leukemia-associated fusion protein AML1/MDS1/EVI1, product of the t(3;21), abrogates growth-inhibition in response to TGF-beta1.

MDS1/EVI1, located on chromosome 3 band q26, encodes a zinc-finger DNA-binding transcription activator not detected in normal hematopoietic cells but expressed in several normal tissues. MDS1/EVI1 is inappropriately activated in myeloid leukemias following chromosomal rearrangements involving band 3q26. The rearrangements lead either to gene truncation, and to expression of the transcription repressor EVI1, as seen in the t(3;3)(q21;q26) and inv(3)(q21q26), or to gene fusion, as seen in the t(3;21)(q26;q22) which results in the fusion protein AML1/MDS1/EVI1. This fusion protein contains the DNA-binding domain of the transcription factor AML1 fused in-frame to the entire MDS1/EVI1 with the exclusion of its first 12 amino acids. In this report, we have analyzed the response of the hematopoietic precursor cell line 32Dcl3, expressing either the normal protein MDS1/EVI1 or the fusion protein AML1/MDS1/EVI1, to factors that control cell differentiation or cell replication. The 32Dcl3 cells are IL-3-dependent for growth and they differentiate into granulocytes when exposed to G-CSF. They are growth-inhibited by TGF-beta1. We show that whereas the expression of MDS1/EVI1 has no effect on granulocytic differentiation induced by G-CSF, expression of AML1/MDS1/EVI1 blocks differentiation resulting in cell death. This effect is similar to that previously described by others for 32Dcl3 cells that express transgenic Evil. Furthermore, we show that whereas the expression of the fusion protein AML1/MDS1/EVI1 completely abrogates the growth-inhibitory effect of TGF-beta1 and allows 32Dcl3 cells to proliferate, expression of the normal protein MDS1/EVI1 has the opposite effect, and it strengthens the response of cells to the growth-inhibitory effect of TGF-beta1. By using the yeast two-hybrid system, we also show that EVI1 (contained in its entirety in MDS1/EVI1 and AML1/MDS1/EVI1) physically interacts with SMAD3, which is an intracellular mediator of TGF-beta1 signaling. Finally, we have correlated the response of the cells to G-CSF or TGF-beta1 with the ability of the normal and fusion proteins to activate or repress promoters which they can directly regulate by binding to the promoter site. We propose that mutations of MDS1/EVI1 either by gene truncation resulting in the transcription repressor EVI1 or by gene fusion to AML1 lead to an altered cellular response to growth and differentiation factors that could result in leukemic transformation. The different response of myeloid cells ectopically expressing the normal or the fusion protein to G-CSF and TGF-beta1 could depend on the different transactivation properties of these proteins resulting in divergent expression of downstream genes regulated by the two proteins.

Cell Differentiation↗

Expression pattern shifts following duplication indicative of subfunctionalization and neofunctionalization in regulatory genes of Arabidopsis.

Gene duplication plays an important role in the evolution of diversity and novel function and is especially prevalent in the nuclear genomes of flowering plants. Duplicate genes may be maintained through subfunctionalization and neofunctionalization at the level of expression or coding sequence. In order to test the hypothesis that duplicated regulatory genes will be differentially expressed in a specific manner indicative of regulatory subfunctionalization and/or neofunctionalization, we examined expression pattern shifts in duplicated regulatory genes in Arabidopsis. A two-way analysis of variance was performed on expression data for 280 phylogenetically identified paralogous pairs. Expression data were extracted from global expression profiles for wild-type root, stem, leaf, developing inflorescence, nearly mature flower buds, and seedpod. Gene, organ, and gene by organ interaction (G x O) effects were examined. Results indicate that 85% of the paralogous pairs exhibited a significant G x O effect indicative of regulatory subfunctionalization and/or neofunctionalization. A significant G x O effect was associated with complementary expression patterns in 45% of pairwise comparisons. No association was detected between a G x O effect and a relaxed evolutionary constraint as detected by the ratio of nonsynonymous to synonymous substitutions. Ancestral gene expression patterns inferred across a Type II MADS-box gene phylogeny suggest several cases of regulatory neofunctionalization and organ-specific nonfunctionalization. Complete linkage clustering of gene expression levels across organs suggests that regulatory modules for each organ are independent or ancestral genes had limited expression. We propose a new classification, regulatory hypofunctionalization, for an overall decrease in expression level in one member of a paralogous pair while still having a significant G x O effect. We conclude that expression divergence specifically indicative of subfunctionalization and/or neofunctionalization contributes to the maintenance of most if not all duplicated regulatory genes in Arabidopsis and hypothesize that this results in increasing expression diversity or specificity of regulatory genes after each round of duplication.

Arabidopsis↗

Control of the expression of the manXYZ operon in Escherichia coli: Mlc is a negative regulator of the mannose PTS.

The manXYZ operon of Escherichia coli encodes a sugar transporter of the phosphoenol pyruvate (PEP)-dependent phosphotransferase system, which is capable of transporting many sugars, including glucose, mannose and the aminosugars, glucosamine and N-acetylglucosamine. Transcription of manX is strongly dependent on cyclic AMP (cAMP)/cAMP receptor protein (CAP). A cAMP/CAP binding site is located at -40.5, and activation by cAMP/CAP is shown to be typical of a class II promoter. The 5' end of a transcript, potentially encoding two proteins, is expressed divergently from the manXYZ operon. Previously, two binding sites for the NagC repressor were detected upstream of manX, but a mutation in nagC has very little effect on manX expression. However, a mutation in the mlc gene, encoding a homologue of nagC, results in a threefold derepression of manX expression, suggesting that this protein is a more important regulator of manX expression than NagC. The Mlc protein binds to the NagC operators, binding preferentially to the promoter-proximal operator. Plasmids overproducing either the NagC protein or the Mlc protein repress the expression of manX, but the effect of the Mlc protein is stronger. The mlc gene is shown to be allelic with the previously characterized dgsA mutation affecting the mannose phosphoenolpyruvate-dependent phosphotransferase system (PTS).

Bacterial Outer Membrane Proteins↗

Tissue distribution and hormonal regulation of the breast cancer resistance protein (Bcrp/Abcg2) in rats and mice.

Breast cancer resistance protein (Bcrp/Abcg2) is a member of the ABC transporter family. The purpose of this study was to quantify Bcrp mRNA in rat and mouse tissues, and to determine whether there are gender differences in Bcrp mRNA expression. Rat Bcrp mRNA levels were high in intestine and male kidney, and intermediate in testes. Mouse Bcrp expression was highest in kidney, followed by liver, ileum, and testes. Male-predominant expression of Bcrp was observed in rat kidney and mouse liver. Furthermore, gonadectomy and hypophysectomy experiments were conducted to determine whether sex steroids and/or growth hormone are responsible for Bcrp gender-divergent expression patterns. Male-predominant expression of Bcrp in rat kidney appears to be due to the suppressive effect of estradiol, and male-predominant expression of Bcrp in mouse liver appears to be due to the inductive effect of testosterone.

ATP Binding Cassette Transporter, Subfamily G, Mem↗

A flagellar calmodulin gene of Naegleria, coexpressed during differentiation with flagellar tubulin genes, shares DNA, RNA, and encoded protein sequence elements.

Two calmodulins are synthesized during differentiation of Naegleria gruberi from amoebae to flagellates; one remains in the cell body and the other becomes localized in the flagella. The single, intronless, expressed gene for flagellar calmodulin has been cloned and sequenced. The encoded protein is a typical calmodulin with four putative calcium-binding domains, but it has an amino-terminal extension of 10 divergent amino acids preceding conserved calmodulin residue 4. The transcripts encoding flagellar calmodulin and flagellate cell body calmodulin are clearly divergent. Expression of the flagellar calmodulin gene is differentiation-specific; its mRNA appears and then disappears concurrently with those encoding flagellar alpha- and beta-tubulin. Three provocative sequence elements are shared among these unrelated coexpressed genes: (i) a palindromic DNA sequence element is found in duplicate or triplicate upstream to each transcribed region; (ii) a perfect 12-nucleotide match is found near the AUG start codon of flagellar calmodulin and alpha-tubulin; and (iii) the novel amino-terminal extension of flagellar calmodulin contains a 5-amino-acid element similar to the amino terminus of flagellar alpha-tubulin. These shared sequence elements are proposed to have roles in differentiation, possibly in regulation of transcription, mRNA stability, and localization of these proteins to flagella.

Amino Acid Sequence↗

Expression of a new operon from Bacillus subtilis, ykzB-ykoL, under the control of the TnrA and PhoP-phoR global regulators.

The ykzB and ykoL genes encode two peptides, of 51 and 60 amino acids, the functions of which are unknown. The ykzB and tnrA genes are contiguous and transcribed divergently. Expression of ykzB and ykoL is induced by glutamate and is under the control of the TnrA global regulator of nitrogen utilization. TnrA regulated its own synthesis in glutamate minimal medium. Two DNA sequences (TnrAB1 and TnrAB2) homologous to the TnrA binding site are present in the region between tnrA and ykzB. Deletion mapping indicated that the TnrAB2 binding site was involved in activation of the ykzB promoter. In addition, transcription of tnrA depends on the presence of the TnrAB1 binding site. The ykzB and ykoL genes are probably in the same transcriptional unit. A single promoter involved in transcription in the presence of glutamate was mapped by primer extension. ykoL expression was induced by phosphate limitation and depended on the PhoP-PhoR two-component regulatory system. Its promoter was mapped to the region between ykoL and ykzB. Four boxes similar to the PhoP binding site are present upstream from the ykoL promoter. These boxes are probably recognized by PhoP approximately P during the activation of transcription in phosphate limitation conditions.

Bacillus subtilis↗

Cloning and characterization of cDNAs for hormones and/or receptors of growth hormone, insulin-like growth factor-I, thyroid hormone, and corticosteroid and the gender-, tissue-, and developmental-specific expression of their mRNA transcripts in fathead minnow (Pimephales promelas).

Growth hormone (GH), insulin-like growth factor-I (IGF-I), thyroid hormones, and corticosteroids play central roles in a wide range of body functions but, in fish, information on their interactions is limited. These axes of the endocrine system are also potential targets for disruption of signaling pathways by hormone-mimicking chemicals, but have received little study. Molecular approaches offer an effective way to help unravel these endocrine interactions but require the appropriate gene-specific assays to do so. In this study, the cDNAs for a suite of hormones and/or receptors involved in signaling for the effects of GH and IGF-I [GH, GH receptor (GHR), IGF-I, IGF-I receptor (IGF-IR)], thyroid hormones [thyroid hormone receptor alpha (TRalpha) and beta (TRbeta)], and corticosteroids [glucocorticoid receptor (GR)] were cloned from the fathead minnow (Pimephales promelas; fhm), and the tissue-, developmental-, and gender-related expression of their mRNA transcripts established. By polymerase chain reaction (PCR) strategy, we obtained full-length 1123-bp GH, 817-bp IGF-I, 1584-bp TRbeta, and 2571-bp GR cDNAs, coding for 210 amino acid (aa) GH, 161 aa IGF-I, 378 aa TRbeta, and 745 aa GR putative proteins, and partial-length 158-bp GHR, 811-bp IGF-IR, and 446-bp TRalpha cDNAs. Real-time PCR analyses revealed broad tissue expression for the target mRNAs; all targets were expressed in brain, pituitary, gill, liver, gonad, intestine, and muscle, with the exception of GH that was expressed only in the pituitary and gonad. Expression patterns in both juvenile and adult fhm were complex, with both temporal-, tissue-, and sex-specific characteristics. For example, hepatic expressions of GHR, IGF-I, and IGF-IR were far higher in males than in females, possibly reflecting the sex-related dimorphism in growth that occurs in this species, and TRalpha and TRbeta showed divergent expression patterns during development (where TRbeta predominated) and in adult tissues implying some distinct roles for the two TR subtypes.

Adrenal Cortex Hormones↗

Expression of intermediate filaments in established human lung cancer cell lines. An indicator of differentiation and derivation.

A panel of established human pulmonary cancer cell lines, representing the major histopathologic groups according to the World Health Organization (WHO) classification (WHO 1, squamous cell carcinoma; WHO 2, small cell carcinoma; WHO 3, adenocarcinoma; WHO 4, large cell carcinoma) were examined for their expression of various types of intermediate filaments in order to determine their phenotypic differences and to attempt to disclose their histogenetic origin. The cells were investigated with antibodies specific for cytokeratin, vimentin, and neurofilament polypeptides with both immunofluorescence microscopy and immunoblotting techniques. Squamous cell carcinoma and adenocarcinomas expressed cytokeratin in accordance with the epithelial nature of these tumors but not neurofilament polypeptides. Small cell carcinomas, on the other hand, were positive for neurofilaments but negative for keratin. In contrast to small cell carcinoma, adenocarcinoma, and squamous cell carcinoma, one cell line derived from large cell carcinoma appeared to express both neurofilaments and keratin. All cell lines studied also contained variable amounts of vimentin, a phenotypic characteristic obtained by many cells under in vitro conditions. The results demonstrate, in accordance with our earlier observations in vivo, a distinctly divergent expression of intermediate filament proteins in different types of lung cancers. The persistence of this phenotypic heterogeneity in vitro consolidates the use of cell cultures as useful models to study the biologic behavior and interrelationships of lung cancers. Based on the present studies, and taking into account the occurrence of mixed forms of lung cancers, we present a hypothetical scheme of the histogenetic derivation of different types of lung cancers.

Adenocarcinoma↗