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At least 19 recordsLinked to original sources
PubMed2026

Advanced and underlying therapeutic strategies in transformed small cell lung cancer.

Transformed small-cell lung cancer (T-SCLC) is a clinically important form of histologic transformation and a mechanism of acquired resistance in non-small-cell lung cancer (NSCLC). It is associated with poor prognosis, with a median overall survival of only about 9-13 months. This review summarizes recent advances in the mechanisms, diagnosis, monitoring, and treatment of T-SCLC. Repeat biopsy remains the gold standard for confirming histologic transformation, whereas molecular profiling and liquid biopsy may facilitate early detection and longitudinal disease monitoring. Platinum-etoposide remains the most commonly used clinical standard after transformation, but its benefit is typically transient and durable disease control remains uncommon. Continuation of EGFR tyrosine kinase inhibitors combined with chemotherapy may prolong progression-free survival in selected patients but has not consistently improved overall survival. Anti-angiogenic therapy, particularly anlotinib, and chemo-immunotherapy have shown encouraging activity in selected patients, while emerging strategies targeting DLL3, MYC, SOX2, and epigenetic regulators may broaden the therapeutic landscape. Prospective studies integrating repeat tissue sampling, comprehensive genomic profiling, biomarker-guided patient stratification, pharmacogenomics, functional drug-sensitivity testing where feasible, and integrated multi-omics approaches are needed to advance molecularly guided and individualized treatment for T-SCLC.

advanced therapy↗
PubMed2026

EGFR-Mutant Non-Small Cell Lung Cancer With Small Cell Transformation: Clinicopathological Features, Treatment Landscape, and Biomarker Profiles.

INTRODUCTION: Transformed small-cell lung cancer (tSCLC) is a clinically important resistance mechanism to EGFR tyrosine kinase inhibitors in EGFR-mutant non-small cell lung cancer. This study characterizes clinical features, treatment outcomes, and biomarker profiles in patients with tSCLC. METHODS: Data from 45 patients with EGFR-mutant NSCLC who developed tSCLC between 2014 and 2023 were analyzed. Demographic characteristics, treatment histories, and delta-like ligand 3 (DLL3) and B7-H3 expression were collected. Objective response rate, progression-free survival (PFS), and posttransformation survival (PTS) were assessed. Spatial transcriptomic profiling was performed in selected cases. RESULTS: Most patients were women (60%) and never-smokers (75.6%). Exon 19 deletion was the predominant EGFR mutation (57.8%). Median PFS and PTS were 3.3 and 9.2 months, respectively. Etoposide plus platinum (EP) was the predominant first-line regimen (69.8%), with 23.2% of the patients receiving EP plus immune checkpoint or tyrosine kinase inhibitors. EP-based combination regimens yielded a numerically higher objective response rate and a significantly longer PFS than EP alone (7.5 versus 2.8 months, p = 0.002). PTS was longer with EP-based regimens than with other regimens (10.4 versus 6.4 months, p = 0.035). DLL3 and B7-H3 were expressed in 87.5% and 66.7% of tumors, respectively, without prognostic significance. Multivariable analysis identified brain metastasis and liver progression at transformation as adverse prognostic factors. Spatial transcriptomic analysis revealed neuroendocrine lineage reprogramming, stromal depletion, and immune exclusion. CONCLUSIONS: tSCLC remains an aggressive resistance phenotype with poor outcomes. EP-based combination strategies may provide clinical benefit, whereas frequent DLL3 expression supports further evaluation of targeted therapies.

Delta-like ligand 3↗
PubMed2026

EGFR-mutant transformed small cell lung cancer harbors intratumoral heterogeneity targetable with MEK inhibitor combination therapy.

Small cell lung cancer (SCLC) transformation is an incompletely characterized mechanism of resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in EGFR-mutant cancers, limiting development of optimal treatment approaches. Through single-cell RNA sequencing of malignant pleural effusions from patients who underwent SCLC transformation, we identified heterogeneity and diversity, including distinct neuroendocrine (NE) and mesenchymal non-NE cancer cell subsets, which were maintained in patient-derived cell lines. We demonstrate that EZH2 regulates EGFR expression in NE cells where EGFR expression is silenced at baseline. Although neither epigenetic derepression nor exogenous overexpression of mutant EGFR sensitized the cells to EGFR inhibition, non-NE cells exhibited selective sensitivity to MEK inhibitors. Combined MEK inhibitor and chemotherapy effectively inhibited growth of both NE and non-NE cells in vitro and in vivo. Our findings demonstrate that EGFR-mutant SCLC is composed of mixed cell states with distinct therapeutic vulnerabilities and offer a therapeutic strategy to target tumor heterogeneity in highly plastic and treatment-resistant malignancies such as transformed SCLC.

Humans↗
PubMed2026

Genomic Profiling, Risk Stratification, and Post-Transformation Treatment Outcomes in Patients with Transformed Small-Cell Lung Cancer: A Multicenter Analysis.

BACKGROUND: Transformed small-cell lung cancer (T-SCLC) is an increasingly recognized resistance mechanism in EGFR-mutant lung adenocarcinoma. This study aimed to identify early predictors of histologic transformation and evaluate post-transformation treatment outcomes. METHODS: We retrospectively collected 163 T-SCLC patients from five Chinese centers. Next-generation sequencing was performed on 60 EGFR-mutant patients, including 47 paired primary-transformed samples. Integrated genomic and clinical analyses were conducted to delineate molecular features and survival outcomes. RESULTS: Among 150 EGFR-mutant patients, the median time to SCLC transformation was 25.8 months and median post-transformation overall survival (OS) was 14.2 months. Clinical and survival data for the 13 EGFR wild-type patients are reported descriptively given the limited sample size. Among 108 treatment-evaluable patients, first-line EGFR-TKI plus chemotherapy, chemotherapy alone, and immune checkpoint inhibitors (ICIs) plus chemotherapy yielded median progression-free survival (PFS) of 6.2, 5.30, and 4.07 months (P = 0.041) and median OS of 21.2, 27.6, and 13.6 months (P = 0.193). In later-line therapy, taxane-based regimens achieved a median PFS of 6.93 months, outperforming camptothecin-based (1.13 months) and other regimens (1.90 months; P = 0.049). High evolutionary diversity was associated with shorter post-transformation OS (6.77 vs. 11.10 months), with restricted cubic spline analysis showing a nonsignificant trend toward a nonlinear association (P = 0.055).Age, RB1/NTRK1 mutation, and secondary T790M mutation were identified as independent risk factors and integrated into a predictive model with high accuracy. CONCLUSIONS: This study establishes a clinically applicable model for early prediction and risk stratification of SCLC transformation. Taxane-based regimens emerge as a promising later-line therapeutic option for T-SCLC.

Humans↗
PubMed1975

Fibrin overlay methods for the detection of single transformed cells and colonies of transformed cells.

Fibrin overlay methods are described which can detect the plasminogen activator produced by single transformed cells or small colonies of transformed cells. These methods were applied to malignant cells derived from humans, mice, hamsters, rats, and chicks. The lysis observed was plasminogen dependent. Transformation of chicken cells by Rous sarcoma virus was detected 4 days after infection. The number of lysis zones produced was proportional to the virus inoculum and was identical to the number of morphologically determined foci. These methods may also have application in model systems for scoring transformation by chemicals. Transformed mouse and chicken cells were detected at the single cell level and the number of lysis zones produced was dependent on the number of cells present, the time of incubation, and the concentration of plasminogen.

Animals↗
PubMed1978

Transcription of the transforming region of adenovirus type 5 in a rat cell line transformed by a small restriction fragment.

The fraction of the adenovirus type 5 genome expressed as mRNA in a rat cell line, 5RK, transformed by the HsuI-G restriction fragment was analyzed by saturation hybridization using separated strands of 32P-labeled HindIII-G fragment. It was found that 45 to 50% of G fragment (about 8 X 10(5) daltons) is expressed as mRNA. The size of polyadenylic acid-terminated virus-specific cytoplasmic and nuclear RNA was determined by electrophoresis on polyacrylamide gels containing 98% formamide, followed by hybridization of gel slices with viral DNA. The major virus-specific RNA species present in the cytoplasm is about 14S, whereas the major virus-specific RNA present in the nucleus is 30 to 32S. The large size of nuclear virus-specific RNA suggests that host sequences are covalently linked to the viral transcript.

Adenoviruses, Human↗
PubMed1979

Characterization of different tumor antigens present in cells transformed by simian virus 40.

In addition to large T and small t antigens, cells transformed by simian virus 40 (SV40) commonly contain other proteins which specifically immunoprecipitate with SV40 anti-T serum and which are not detected in untransformed cells. The additional tumor antigens (T-Ags) fall into two groups: those having a close structural relationship with normal SV40 T-Ags, and those unrelated to large T and small t. The latter are probably nonviral T-Ags (NVT-Ags). The NVT-Ags comprise a family of proteins of molecular weight 50,000-55,000. Fingerprint analysis shows that NVT-Ags have few if any peptides in common with large T or small t, and that they lack the amino terminal tryptic peptide and the peptides unique to small t. NVT-Ags from different species have different fingerprints, but those isolated from different transformants of the same cell line are identical. The size of NVT is unaltered in cells transformed by mutants of SV40 with deletions in the region 0.60-0.55 map units. The mRNA for NVT does not hybridize to SV40 DNA. The other forms of T-Ag isolated from transformed cells fall into three classes: shortened forms of large T (truncated large T); multiple species of T-Ag with molecular weights very similar to, but distinct from, those of normal large T (large T doublets and triplets); and elongated forms of large T (super T). These proteins all contain the normal amino terminus of SV40 T-Ags, and the truncated forms of large T lack peptides from the carboxy terminal half of large T. One species of super T (molecular weight 130,000) contains only those methionine tryptic peptides present in normal large T, although it may contain some peptides in more than one copy.

Animals↗
PubMed2026

Role of ctDNA Tumor Fraction in Selecting Immunotherapy-Based Regimens in Advanced Non-Small Cell Lung Cancer.

PURPOSE: Immune checkpoint blockers (ICB) have transformed advanced non-small cell lung cancer (aNSCLC) treatment, but identifying patients who benefit from adding chemotherapy remains challenging, especially in PD-L1 &#x2265; 50%. PD-L1 is an imperfect biomarker, highlighting the need for better selection tools. EXPERIMENTAL DESIGN: Liquid biopsy (LBx) assessment was performed using hybrid capture-based next-generation sequencing of plasma cell-free DNA. LBx data, molecular profile, and clinicopathologic data were collected. The predictive and prognostic values of tumor fraction (TF) were assessed using a deidentified nationwide (US-based) NSCLC clinicogenomic database [Clinico-Genomic Database (CGDB)]. An independent cohort with aNSCLC from Gustave Roussy was used to validate the findings and to study the correlation of circulating tumor DNA (ctDNA) TF and total metabolic tumor volume and its molecular correlates. RESULTS: In the CGDB database (n = 965), elevated ctDNA TF was prognostic for worse outcomes on ICBs and, when &#x2265;5%, predictive of benefit from ICB + chemotherapy [HR for real-world progression-free survival 0.58 (0.41-0.82); P = 0.002]. The 5% cutoff for TF was validated in an independent cohort from Gustave Roussy. In 283 patients with paired PET scans, ctDNA TF correlated with metabolic tumor volume (rho = 0.46; P < 0.001) and was influenced by TP53/RB1 mutations. CONCLUSIONS: ctDNA TF integrates disease burden and biology. Patients with high ctDNA TF derive greater benefit from chemoimmunotherapy, supporting its use as a biomarker to guide treatment intensification.

Humans↗
PubMed1978

[Histology of cerebellar metastasis of bronchial oat cell carcinoma].

Anatomo-pathological examination of 28 bronchic oat-cell carcinoma, all with cerebellar metastases and which are very often cerebral. In half of the cases, these localized cerebellar metastases contain palisades. These formations which haven't been described until now within intracranial metastases, can't be considered as artefacts as their frequency approaches 50% of the cases. Neither the primitive tumor nor the extracerebral metastases of the series reveal palisades; sometimes some of them exist in their cerebral metastases. As far as the epidemiology, the clinical evolution, the survival time and the extracerebral localization are concerned, these 28 cases are not different from those described in medical literature. The morphological, hormonal and biochemical knowledge we possess about this type of cancer tends to prove its neuroectodermic origin as well as its close relation with both the APUD- and the "endocrinien diffus" systems. The described palisading elements represent another very specific morphological point which tends to support this theory: they appear principally in the tumors of the central and peripheral nervous system. Although the author is not able to explain the reason of palisades' genesis in cerebellar metastases, he insists on the fact that it iw very important - as far as every days' biopsy's study is concerned - to proceed to a differential histological diagnosis in regards to certain primitive tumors of the nervous system (among these the medulloblastoma) and a cerebellar metastasis of this type of bronchic carcinoma.

Aged↗
PubMed1979

Sheep erythrocyte rosette formation and phytohemagglutinin-stimulated cells. Two cases of mycosis fungoides with skin tumors and lymph nodes.

Infiltrating cells were harvested by mechanical means from skin tumors and lymph nodes of myocis fungoides. Sheep erythrocyte rosette formation was observed on more than 90% of small lymphocyte-like cells with irregular nuclei but seemed to be hardly detectable on larger cells. The small and large cells that formed erythrocyte rosettes showed similar basic ultrastructures, which suggested that these two types of cells are of the same origin. When cultured with phytohemagglutinin (PHA), 90% of the small cells underwent transformation, and they were found to be lymphoblast-like cells with irregular nuclei by electron microscopy. Only 40% of the large cells were transformed with PHA.

Aged↗
PubMed1977

[Developmental anomalies of the liver and carcinoma of the liver in infants and children (author's transl)].

Several forms of intrahepatic developmental anomalies were found on histological examination in 40 children, among them several siblings and polyovular twins. These anomalies affect in principle all structural elements of the liver. In several cases--some of them complicated by cholangitis-there was cholangiofibrosis and cholangiodysplastic pseudo-cirrhosis. In addition, in six children there developed hepatocellular carcinoma between the ages of six months and twelve years. In the course of the development of hepatic carcinoma obligatory nodular for occur. They are made up of light, glycogen-loaded epithelial cells, which later are transformed into small atypical, basophilic cells. These dark cells have a high mitosis rate, have already escaped from the physiological regulation of proliferation. Presumably the various embryonic disorders of liver structure and carcinoma of the liver are based on the action of the same causative factor, which may be of chemical-toxic origin and transferred across the placenta.

Age Factors↗
PubMed1977

[Ultrastructural and enzyme-histochemical alterations of the dog prostate following castration (author's transl)].

Orchiectomy leads to morphologic and functional alterations of the prostate in dogs within 120 days. The glandular epithelium of the acini under the light microscope shows an advanced atrophy with some remaining slit-like lumina. Ultrastructurally, castration results in loss of cell polarity with preserved epithelial compounds. The columnar epithelium is transformed into small polygonal cells with regressive alterations of nucleus, rough endoplasmatic reticulum, mitochondria and Golgi apparatus. These cells show depositions of lipoids and glycogen. Functionally, gonadectomy results in a loss of secretory activity correspondingly secretory granules that are normally present in large numbers are conspicuously absent, the reduction of rough endoplasmatic reticulum and Golgi apparatus too are expressions of the cessation of synthesis of secretion. This is also indicated by the activity of acid phosphatase that is barely demonstrable in the apical portion of the cytoplasm of atrophic glandular epithelium following castration. Only insignificant changes on the other hand are found in the activity of alkaline phosphatase following withdrawal of androgens, this enzyme does not mirror the atrophy due to castration.

Acid Phosphatase↗
PubMed1977

Transformation with specific fragments of adenovirus DNAs. II. Analysis of the viral DNA sequences present in cells transformed with a 7% fragment of adenovirus 5 DNA.

Five clones of rat kidney cells transformed by a small restriction endonuclease fragment of adenovirus 5 (Ad5) DNA (fragment HsuI G, which represents the left terminal 7% of the adenovirus genome) were analyzed with respect to the viral DNA sequences present in the cellular DNAs. In these analyses, the kinetics of renaturation of 32P-labeled specific fragments of Ad5 DNA was measured in the presence of a large amount of DNA extracted either from each of the transformed cell lines or from untransformed cells. The fragments were produced by digestion of 32P-labeled adenovirus 5 DNA with endo R.HsuI, or by digestion of 32P-labeled fragment HsuI G of adeno 5 DNA with endo R.HpaI. All five transformed lines were found to contain DNA sequences homologous to 75--80% of Ad5 fragment HsuI G only. Clones II and V contained approximately 48 copies per quantity of diploid cell DNA, clone VI about 35 copies, clone IV 22 copies and clone III 5--10 copies. These results indicate that a viral DNA segment as small as 5.5% of the Ad5 genome, contains sufficient information for the maintenance of transformation.

Adenoviruses, Human↗
PubMed1979

Simian virus 40 small t antigen is not required for the maintenance of transformation but may act as a promoter (cocarcinogen) during establishment of transformation in resting rat cells.

Simian virus 40 deletion mutants affecting the 20,000-dalton (20K) t antigen and tsA mutants rendering the 90K T antigen temperature sensitive, as well as double mutants containing both mutations, induced host DNA synthesis in resting rat cells at the restrictive temperature. Nonetheless, the deletion mutants and double mutants did not induce transformation in resting cells even at the permissive temperature. On the other hand, the deletion mutants did induce full transformants when actively growing rat cells were infected; the transformants grew efficiently in agar and to high saturation densities on platic. The double mutants did not induce T-antigen-independent (temperature-insensitive) transformants which were shown previously to arise preferentially from resting cells. Thus, small t antigen was dispensable for the maintenance of the transformed phenotype in T-antigen-dependent rat transformants (transformants derived from growing cells) and may play a role in the establishment of T-antigen-independent transformants. We attempt to establish a parallel between transformation induced by chemical carcinogens and simian virus 40-induced transformation.

Animals↗
PubMed1976

Ultrastructure of cells infiltrating human kidney allografts.

Cell infiltration is commonly observed in human renal allograft biopsies. This infiltration was investigated using electron microscopy for a more precise assessment of the nature of these cells. More than 3000 cells infiltrating twenty-five renal allograft biopsies were studied. Six cellular types were distinguished and a mean percentage of each type was calculated. Only one-half of these cells were normal or transformed lymphocytes (including small lymphocytes: 22-3 +/- 3-8%, 'intermediary' cells: 22 +/- 3-6%, blast-like cells similar to MLC transformed lymphocytes: 8-1 +/- 2-4%. A relatively high number of plasmocytes (12-4 +/- 2-5%) and a still higher percentage of macrophages (28-5 +/- 4-6%) were found. Granulocytes represented only 2 +/- 0-8%of the cell population. Variations of the mean percentage of these cellular types were studied in various clinical situations.

Cell Movement↗
PubMed1978

Glucocorticoids induce focus formation and increase sarcoma viral expression in a mink cell line that contains a murine sarcoma viral genome.

Dexamethasone (3 X 10(-10) to 3 X 10(-6) M) induced foci of morphologically transformed cells in a small proportion of a mink cell line that contains the Moloney murine sarcoma viral genome (S+L-). The induction was glucocorticoid specific, since other steroids with glucocorticoid activity (prednisolone, cortisol, and aldosterone) induced foci with an efficiency that paralleled their glucocorticoid activity, and steroids lacking glucocorticoid activity (17B-estradiol, testosterone, and progesterone) failed to induce foci. Viral antigen, as measured by specific immunofluorescence, was localized to the foci. The induction of foci by dexamethasone (3 X 10(-7)) was accompanied by an approximately 10-fold increase in intracellular Moloney murine sarcoma virus-specific RNA and viral p30 antigen. Removal of dexamethasone was followed by the disappearance of foci and a decrease in viral RNA and p30. In this cell system, therefore, glucocorticoids can affect the intracellular levels of type C viral RNA and protein.

Animals↗