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Publications and source records attributed to S Pathak.
The Harlequin fetus is a distinct genetic entity with a strikingly grotesque appearance. Three siblings (two males, one female) with Harlequin Ichthyosis, a rare form of congenital disorder, born to the same parents are presented. The genetic aspects are discussed and the relevant literature is reviewed.
The fusion of mouse and human melanoma cells that were tumorigenic but had different metastatic capabilities resulted in hybrids that were metastatic when injected intravenously or subcutaneously into nude mice, regardless of whether it was the mouse or the human melanoma clone that was metastatic. The H7 hybrid line, formed by fusing murine nonmetastatic K1735 C19 cells with human metastatic A375 C15 cells retained high metastatic potential over more than 50 sub-culture passages, suggesting that the dominant metastatic phenotype in these hybrid cells was stable. Using fluorescent in situ hybridization (FISH), human chromosome 17 was consistently identified as the predominant human chromosome in the majority of H7 cells tested between passages 20 and 60. Western blot analysis showed that the hybrid cells expressed human nm23 protein, indicating that at least one gene on the human chromosome 17 was functional. Immunocytochemistry and immunoprecipitation showed that the metastatic A375 C15 and H7 cells expressed p53 protein, but that the nonmetastatic K1735 C19 melanoma cells did not. Sequencing the human p53 gene in A375 C15N and H7 showed mutations in exon 7. Using a bioassay technique, we showed that K1735 C19 cells can spread from subcutaneous tumors to the lungs of nude mice yet fail to form metastases. With the addition of human chromosome 17 from A375 C15 cells, which carries a mutant p53 gene, the cells readily formed lung metastases. In this melanoma hybrid, a mutant p53 gene appears to confer a survival advantage on cells arrested in the lungs of nude mice and thus contributes to the growth of metastatic cells.
CONCLUSION: We established a new human pancreatic adenocarcinoma cell line, MDAPanc-28. Studies on this new line indicate that it expressed both acinar and ductal gene products suggesting that the patterns of gene expression in the pancreatic adenocarcinoma from which this cell line arose have features similar to those of the protodifferentiated cells hypothesized by Rutter and his colleagues for the developing pancreas (1,2). BACKGROUND: The cell line arose from a tumor that, like most pancreatic adenocarcinomas, was ductal on the basis of its histological appearance. METHODS: Once the cell line was established in culture, they were subjected to cytogenetic analysis and tested for their ability to grow in nude mice. RNA from the cells was analyzed by Northern blot analysis and PCR of reverse transcribed cDNA for the expression of both acinar and duct cell gene products. DNA was analyzed for the presence of mutated K-ras at codon 12. RESULTS: The cell line expressed trypsin and ribonuclease RNA, which are considered to be acinar cell markers, and carbonic anhydrase II (CAII), which is considered to be a duct-cell markers. The histological appearance of xenografts in nude mice was similar to that of the tumor from which the cell line was established. The chromosome number varied between 46 and 60.
Chromosomal analyses of lymphocytes from lung cancer patients and normal subjects revealed that the X and the Y chromosomes have both structural and numerical abnormalities in higher frequency in patients compared to the controls. These abnormalities included chromatid/isochromatid breaks, translocations, ring formation, and selective nondisjunctions, resulting in multisomies of either the X or Y chromosomes. Possible significance of these genetic abnormalities are discussed in relation to lung cancer patients.
The purpose of this study was to correlate abnormalities in chromosome 14 with the invasive metastatic phenotype of K-1735 murine melanoma cells. Low metastatic K-1735 clone 10 and clone 23 cells were transfected with either basic fibroblast growth factor (bFGF), Kaposi's fibroblast growth factor (kFGF), or c-H-ras gene. A high number of bFGF- and H-ras-transfected cells exhibited chromosome 14 rearrangements. These cells also had increased expression of collagenase IV. The kFGF-transfected cells were highly metastatic but did not have increased expression of collagenase type IV. The kFGF-transfected cells were highly metastatic but did not have increased expression of collagenase type IV, nor abnormalities in chromosome 14. The data imply that karyotypic changes in chromosome 14 are associated with increase expression of collagenase type IV.
The cystogenesis event of Toxoplasma gondii is poorly understood. In order to throw light on it, the effect of tumor necrosis factor-alpha (TNF-alpha) was studied in the Prugniaud strain of the organism. This showed that TNF-alpha increased the number of cysts formed in vitro in human MRC5 fibroblasts. The sphingomyelinase pathway may be involved in mediating the TNF effect, since ceramide (natural form in permeabilized cells or cell-permeable analogue) could mimic the action of TNF. More precisely, our results strongly suggest the involvement of an acidic sphingomyelinase in mediating the effect of TNF; indeed, D609 inhibited both the TNF effect and cyst formation, while arachidonic acid had no effect. Moreover, protein kinase (PKC) seems also to play a role in the process, since phorbol-12-myristate-13-acetate (PMA) enhanced the cyst formation. However, chelerythrine chloride did not prevent the TNF effect, suggesting that several host-cell pathways can affect the cystogenesis event. Taken together, these results suggest the active participation of host-cell components in the cystogenesis of Toxoplasma gondii.
Previous histochemical studies have shown that changes occur in the composition of mucins both in preneoplastic and neoplastic lesions of the gastric mucosa. Since monoclonal antibodies are now available which recognize the protein product of distinct mucin genes, they are likely to provide useful tools for evaluating these changes. Thus, a monoclonal antibody 996/1 raised against a peptide epitope of the colonic mucin MUC2 was examined for its potential as a prognostic indicator in gastric cancer. 996/1 works well on formalin-fixed paraffin sections and shows good staining of the colonic goblet cells in the region of the golgi, while there is no staining of normal control gastric mucosa. The epitope was detected in all cases of intestinal metaplasia (44 samples) and some but not all cases of dysplasia (26 samples) and gastric carcinoma (74 samples). There was no significant difference between the positivity of the tumours according to their classification, stage and lymph node status. These results unfortunately gave little indication that this antibody would be a useful prognostic tool in gastric cancer. However, the pattern of 996/1 staining provides useful information about the molecular changes in mucin expression that occur in gastric carcinogenesis.
The purpose of this study was to determine whether the implantation of human prostate cancer cells into the prostates of nude mice and their subsequent growth there can be used to select variants with increasing metastatic potential. PC-3M and LNCaP cells were injected into the prostates of athymic mice. Tumors from the prostate or lymph nodes were harvested, and cells were reinjected into the prostate. This cycle was repeated three to five times to yield cell lines PC-3M-Pro4, PC-3M-LN4, LNCaP-Pro3-5, and LNCaP-LN3-4. Parental and variant cells were injected into the prostates of nude mice. PC-3M-LN4 cells produced enhanced regional lymph node and distant organ metastasis as compared to PC-3M-Pro4 or PC-3M cells. After i.v. or intracardiac inoculation, PC-3M-LN4 cells produced a higher incidence of lung metastasis and bone metastasis, respectively, than PC-3M or PC-3M-Pro4 cells. Subsequent to implantation into the prostate, LNCaP-LN3 cells produced a higher incidence of regional lymph node metastases than LNCaP-Pro5 or LNCaP cells. After intrasplenic implantation, LNCaP-LN3 cells also yielded experimental liver metastases. The metastatic LNCaP-LN3 cells exhibited clonal karyotypic abnormalities, were less sensitive to androgen (in vitro and in vivo), and produced high levels of prostate-specific antigen. Collectively, the data show that the orthotopic implantation of human prostate cancer cell lines in nude mice is a relevant model with which to study the biology of prostate cancer metastasis and to select variant cell lines with enhanced metastatic potential.
The genomic activity and polymorphisms of nucleolus organizer regions (NORs) were studied in an individual with routinely used AgNO3 and Q-banding techniques. The results demonstrate that (a) the mean number of NORs per metaphase spread was 7.4, (b) chromosomes 14, 13, 15, and 21 showed variations of Ag-NOR in decreasing order, (c) chromosome 22 did not show a polymorphism in any cell examined, and (d) both chromosomes 14 showed silver staining in most cells. Unlike many earlier reports indicating that NOR variants were constitutional in each individual, our present case represented a mosaic pattern of polymorphism involving most of the D- and G-group chromosomes.
The integrins are a family of integral membrane receptors that participate in binding to various extracellular and cell surface proteins during adhesion, migration, and homing of normal and neoplastic cells. In this study, we characterized the involvement of integrins in mediating the growth of an adhesion-dependent gastric adenocarcinoma line, ST2. This line was distinguished and selected for study based on its inability to grow when suspended in soft agar or plated on poly(2-hydroxyethyl methacrylate)-coated dishes. ST2 cells arrested in G0/G1 of the cell cycle when deprived of adhesion to substrate. Using purified matrix components, collagen was found to be highly active in promoting beta 1 integrin-mediated cell attachment and spreading. Subsequent to spreading on collagen, the cells were released from G0/G1 block and progressed into S phase. Monoclonal antibodies to alpha 2 or beta 1 integrin blocked the reinduction of both cell spreading and entry into S phase. These studies suggest that during the metastatic process, integrin receptor interaction with the insoluble matrix may be an important step leading to proliferation of some tumors.
Recurrent pleural effusions from a 45-year-old man who was diagnosed as having non-Hodgkin's lymphoma of immunoblastic type were studied cytogenetically. The majority of the metaphases were tetraploid, but there were also lymphoma cells observed with pseudodiploid chromosome constitutions. Cytogenetic analysis by G-banding revealed the existence of at least two cell populations. The karyotype of the minor pseudodiploid clone, which exhibited partial trisomy of 1q11qter and monosomy of 6p11pter as sole abnormalities, was 46,XY,der(6)t(1;6)(q11;p11). The karyotype of the major clone was 92,XXYY,-1,der(6)t(1;6)(q11;p11)x2, +9. The ancestral diploid clone, carrier of the balanced translocation involving chromosomes 1 and 6, was not observed even in the first pleural effusion harvest. The high proportion of tetraploid cells in the recurrent effusions was an indication that these cells were favorably selected in the environment of the somatic cavity. Our cytogenetic findings suggest that partial trisomy of 1q may be a crucial secondary chromosomal abnormality in highly malignant non-Hodgkin's lymphoma. This genetic imbalance was predetermined from the primary abnormality and may be responsible for further tumor progression, as suggested from the clonal evolution in this particular case and, therefore, may be associated with the aggressive biologic behavior of malignant cells.
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Cells derived from individuals with ataxia telangiectasia (AT) show enhanced spontaneous levels of chromosomal abnormalities and are sensitive to ionizing radiations and radiomimetic drugs, as evidenced by decreased survival and increased chromosome aberration frequencies at mitosis when compared with normal cell lines. The higher base line frequencies of chromosome aberrations in part involve chromosome end-to-end associations as seen at metaphase. Since telomeres of tumor cells and aging tissues are often reduced in length, chromosome end associations may be due to loss of telomeric repeats. We studied the chromosome behavior and telomeres of two ataxia telangiectasia lymphoblastoid cell lines compared to two normal control cell lines. The ataxia telangiectasia cell lines showed higher frequencies of chromosome end associations both at metaphase and in interphase, determined in prematurely condensed chromosomes of G1 and G2 cells. They also showed higher frequencies of chromosomal breaks at metaphase and fewer telomeric signals determined using fluorescent in situ hybridization with a (TTAGGG)n probe. The frequency of telomeric repeats was variable in the ataxia telangiectasia cell lines (4.3 and 8.2 kb) compared to the normal cell lines (9.6 and 12 kb) and an inverse correlation between telomere length and chromosome end associations was observed. Both ataxia telangiectasia cell lines showed more robust telomerase activity than the normal cell lines, precluding defective enzymatic capacity as the basis for the chromosome end associations. It is possible that chromatin structure in the form of telomere-nuclear matrix interactions are variant in ataxia telangiectasia cells negatively influencing telomerase function and contributing to telomere associations.
PURPOSE: These studies were designed to develop an orthotopic model for human bladder cancer and to isolate variant metastatic cell lines. MATERIALS AND METHODS: The human bladder cancer cell line 253J was implanted into the muscular wall of the bladder of athymic nude mice. By in vivo recycling, we selected for 2 variant cell lines: 253J B-V, a bladder line isolated after 5 serial passages in the bladder, and 253J lung-IV, established from a lung tumor nodule that was recycled through the bladder. RESULTS: These 2 cell lines showed enhanced tumorigenicity, as measured by a decreased latent period, and rapid growth as compared with the parental cell line. Moreover, orthotopic implantation of these cell lines resulted in metastasis to the lungs. These in vivo-selected, metastatic cell lines exhibited unique karyotypic alterations, increased anchorage-independent growth, overexpression of basic fibroblast growth factor, altered expression of adhesion molecules and the ability to migrate through Matrigel. CONCLUSIONS: This reproducible model of human bladder cancer offers the opportunity to study cellular properties associated with tumor progression and metastasis and is suitable for the evaluation of new therapeutic strategies for invasive bladder cancer.
Effect of hexane extract of Ferula jaeschkeana has been studied on corpora lutea of adult cyclic guinea-pigs. Administration of extract showed duration dependent luteolytic changes in the corpora lutea. Its administration for first three days from the onset of estrus caused significant decrease in the diameter of corpora lutea in the ovary at day 10 of cycle. Ovarian wet weight, proteins and glycogen contents were decreased while the activity of acid phosphatase in the ovary was increased. These luteolytic changes in the ovary have also been observed in the histological findings. Administration of extract for other durations (4-6, 7-9 or 10-12 of cycle) did not cause any change at 10th and 16th day.
Our laboratory has previously reported on the derivation of LNCaP cell sublines from LNCaP tumors maintained in castrated and intact athymic male mice. These LNCaP sublines differ from the parental line in tumorigenicity and androgen dependence. This paper demonstrates that one of these sublines acquired metastatic potential. When inoculated either s.c. or orthotopically, the C4-2 subline metastasized to the lymph node and bone with an incidence of 11-50%. Interestingly, the incidence of osseous metastasis was higher in castrated than in intact male hosts. We evaluated the chromosomal, immunohistochemical, and biochemical characteristics of the LNCaP sublines derived from C4-2 tumors that metastasized to the lymph node and bone. Cytogenetic analysis showed that all sublines were human and shared common marker chromosomes with the parental LNCaP cells. This experimental human prostate cancer model may permit, for the first time, the study of the molecular mechanisms underlying human prostate cancer metastasis.
A model of human prostate cancer was established to study cellular interaction between prostate cancer and bone stroma in vivo. In this model, subcutaneous co-injection of 2 non-tumorigenic human cell lines--LNCaP, a prostate cancer cell line, and MS, a bone stromal cell-line--into intact adult male mice resulted in formation of carcinomas that secreted prostate-specific antigen (PSA), a clinically useful human serum prostate cancer marker. In castrated hosts, upon cellular interaction with bone fibroblasts, we observed the progression of these tumors from an androgen-dependent (AD) to an androgen-independent state (AI). We derived 4 LNCaP cell sublines from the chimeric LNCaP/MS tumors: the M subline from intact hosts and the C4, C4-2 and C5 sublines from castrated hosts. The LNCaP sublines had chromosomal markers similar to those of the parental LNCaP cells and distinctly different from those of the MS bone stromal cell line. Although the parental and derived cell lines expressed similar steady-state levels of ornithine decarboxylase transcript, the sublines expressed 5- to 10-fold higher basal steady-state levels of PSA transcript than did the parental LNCaP cell line. The LNCaP sublines formed 13- to 26-fold more soft-agar colonies than the parental LNCaP cell line. The sublines became tumorigenic, yielding an incidence of tumors in intact athymic mice of 7-75%. The LNCaP sublines C4 and C5 (but not the parental and M cell line) formed tumors in castrated hosts when co-injected with bone fibroblasts. A second-generation LNCaP subline, C4-2, was derived from a chimeric tumor induced by co-inoculating castrated mouse with C4 cells and MS cells. We found that C4-2 subline was tumorigenic when inoculated into castrated hosts in the absence of inductive fibroblasts. Moreover, C4-2 was the only subline capable of forming soft-agar colonies when cultured in serum-free medium. In comparison with the parental LNCaP cells, the C4-2 subline expressed lower steady-state levels of androgen receptor (AR) protein and mRNA transcript and lost its androgen responsiveness in vitro. Our results suggest that certain genetic traits of prostate cancer cells may be selected or altered through an "adaptive" mechanism that involves cellular interaction with the bone stromal cells.
High frequency loss of alleles and cytogenetic aberrations on the short arm of chromosome 3 have been documented in renal cell carcinoma (RCC). Potentially, three distinct regions on 3p could encode tumor suppressor genes involved in the genesis of this cancer. We report that the introduction of a centric fragment of 3p, encompassing 3p14-q11, into a highly malignant RCC cell line resulted in a dramatic suppression of tumor growth in athymic nude mice. Another defined deletion hybrid contained the region 3p12-q24 of the introduced human chromosome and failed to suppress tumorigenicity. These data functionally define a tumor suppressor locus, nonpapillary renal carcinoma-1 (NRC-1), within 3p14-p12, the most proximal region of high frequency allele loss in sporadic RCC as well as the region containing the translocation breakpoint in familial RCC. Furthermore, we provide functional evidence that NRC-1 controls the growth of RCC cells by inducing rapid cell death in vivo.