Clinical and molecular features of acquired resistance to immunotherapy in non-small cell lung cancer

Although immunotherapy with PD-(L)1 blockade is routine for lung cancer, little is known about acquired resistance. Among 1,201 patients with non-small cell lung cancer (NSCLC) treated with PD-(L)1 blockade, acquired resistance is common, occurring in >60% of initial responders. Acquired resistance shows differential expression of inflammation and interferon (IFN) signaling. Relapsed tumors can be separated by upregulated or stable expression of IFNγ response genes. Upregulation of IFNγ response genes is associated with putative routes of resistance characterized by signatures of persistent IFN signaling, immune dysfunction, and mutations in antigen presentation genes which can be recapitulated in multiple murine models of acquired resistance to PD-(L)1 blockade after in vitro IFNγ treatment. Acquired resistance to PD-(L)1 blockade in NSCLC is associated with an ongoing, but altered IFN response. The persistently inflamed, rather than excluded or deserted, tumor microenvironment of acquired resistance may inform therapeutic strategies to effectively reprogram and reverse acquired resistance.

Subclonal Somatic Copy-Number Alterations Emerge and Dominate in Recurrent Osteosarcoma

Multiple large-scale genomic profiling efforts have been undertaken in osteosarcoma to define the genomic drivers of tumorigenesis, therapeutic response, and disease recurrence. The spatial and temporal intratumor heterogeneity could also play a role in promoting tumor growth and treatment resistance. We conducted longitudinal whole-genome sequencing of 37 tumor samples from 8 patients with relapsed or refractory osteosarcoma. Each patient had at least one sample from a primary site and a metastatic or relapse site. Subclonal copy-number alterations were identified in all patients except one. In 5 patients, subclones from the primary tumor emerged and dominated at subsequent relapses. MYC gain/amplification was enriched in the treatment-resistant clones in 6 of 7 patients with multiple clones. Amplifications in other potential driver genes, such as CCNE1, RAD21, VEGFA, and IGF1R, were also observed in the resistant copy-number clones. A chromosomal duplication timing analysis revealed that complex genomic rearrangements typically occurred prior to diagnosis, supporting a macroevolutionary model of evolution, where a large number of genomic aberrations are acquired over a short period of time followed by clonal selection, as opposed to ongoing evolution. A mutational signature analysis of recurrent tumors revealed that homologous repair deficiency (HRD)-related SBS3 increases at each time point in patients with recurrent disease, suggesting that HRD continues to be an active mutagenic process after diagnosis. Overall, by examining the clonal relationships between temporally and spatially separated samples from patients with relapsed/refractory osteosarcoma, this study sheds light on the intratumor heterogeneity and potential drivers of treatment resistance in this disease.

SIGNIFICANCE

The chemoresistant population in recurrent osteosarcoma is subclonal at diagnosis, emerges at the time of primary resection due to selective pressure from neoadjuvant chemotherapy, and is characterized by unique oncogenic amplifications.

Exportin 1 inhibition prevents neuroendocrine transformation through SOX2 down-regulation in lung and prostate cancers

In lung and prostate adenocarcinomas, neuroendocrine (NE) transformation to an aggressive derivative resembling small cell lung cancer (SCLC) is associated with poor prognosis. We previously described dependency of SCLC on the nuclear transporter exportin 1. Here, we explored the role of exportin 1 in NE transformation. We observed up-regulated exportin 1 in lung and prostate pretransformation adenocarcinomas. Exportin 1 was up-regulated after genetic inactivation of TP53 and RB1 in lung and prostate adenocarcinoma cell lines, accompanied by increased sensitivity to the exportin 1 inhibitor selinexor in vitro. Exportin 1 inhibition prevented NE transformation in different TP53/RB1-inactivated prostate adenocarcinoma xenograft models that acquire NE features upon treatment with the aromatase inhibitor enzalutamide and extended response to the EGFR inhibitor osimertinib in a lung cancer transformation patient-derived xenograft (PDX) model exhibiting combined adenocarcinoma/SCLC histology. Ectopic SOX2 expression restored the enzalutamide-promoted NE phenotype on adenocarcinoma-to-NE transformation xenograft models despite selinexor treatment. Selinexor sensitized NE-transformed lung and prostate small cell carcinoma PDXs to standard cytotoxics. Together, these data nominate exportin 1 inhibition as a potential therapeutic target to constrain lineage plasticity and prevent or treat NE transformation in lung and prostate adenocarcinoma.

Lineage tracing reveals clonal progenitors and long-term persistence of tumor-specific T cells during immune checkpoint blockade

Paired single-cell RNA and T cell receptor sequencing (scRNA/TCR-seq) has allowed for enhanced resolution of clonal T cell dynamics in cancer. Here, we report a scRNA/TCR-seq analysis of 187,650 T cells from 31 tissue regions, including tumor, adjacent normal tissues, and lymph nodes (LN), from three patients with non-small cell lung cancer after immune checkpoint blockade (ICB). Regions with viable cancer cells are enriched for exhausted CD8+ T cells, regulatory CD4+ T cells (Treg), and follicular helper CD4+ T cells (TFH). Tracking T cell clonotypes across tissues, combined with neoantigen specificity assays, reveals that TFH and tumor-specific exhausted CD8+ T cells are clonally linked to TCF7+SELL+ progenitors in tumor draining LNs, and progressive exhaustion trajectories of CD8+ T, Treg, and TFH cells with proximity to the tumor microenvironment. Finally, longitudinal tracking of tumor-specific CD8+ and CD4+ T cell clones reveals persistence in the peripheral blood for years after ICB therapy.

Abstract 3594: Exportin 1 inhibition as a therapeutic strategy for small cell lung cancer

Small cell lung cancer (SCLC) is an aggressive disease characterized by early metastasis and exceptional lethality, comprising 13% of all lung cancer cases. With few treatment options, typically resulting in only transient responses, SCLC is responsible for approximately 250,000 deaths globally per year. The backbone of SCLC treatment over the past several decades has been platinum-based doublet chemotherapy, with the recent addition of immunotherapy to first-line chemotherapy showing limited benefit in a small subset of patients. Major hurdles to improving SCLC treatment include development of rapid chemoresistance and ineffective second line therapies. The identification of more durably effective therapeutic strategies is a major unmet clinical need. Here, we performed an in vitro CRISPR screen in SCLC cell lines from all major SCLC subtypes, including short-term cultured cells from patient-derived xenografts (PDXs), to identify potential therapeutic targets to enhance sensitivity to chemotherapy. Candidate hits were validated genetically and pharmacologically with in vitro synergy assays, in vivo clonal competition assays and pharmacologic assessments in PDX models. Signaling pathways were studied by RNA sequencing and western blot, and toxicity studies were performed in vivo to assess the safety of the agents at pharmacologically effective doses. We performed immunohistochemistry (IHC) to assess expression of candidate targets in tissue microarrays (TMAs). Our CRISPR screen revealed the nuclear exporter exportin 1 (encoded by the XPO1 gene) as a promising target sensitizing to chemotherapy, independently of the SCLC subtype. We found that XPO1 mRNA expression was higher in SCLC than in any other solid tumor or hematological malignancy, and demonstrated consistently high protein expression by IHC in clinical TMAs. A potent and selective exportin 1 inhibitor, selinexor, is approved for use in hematological malignancies. Combination of selinexor with cisplatin or irinotecan demonstrated synergy in vitro and efficacy in vivo in an array of chemonäive and chemoresistant SCLC PDXs, including all major SCLC subtypes. The combinations were well tolerated in mice. The chemo-sensitizing effects of selinexor were associated with suppression of chemotherapy-induced AKT activation. In conclusion, exportin 1 inhibition strongly enhances sensitivity of SCLC tumors to cisplatin and irinotecan, used in first line and second line treatment of SCLC tumors, respectively, and these effects are independent of the SCLC subtype. These results provide preclinical rationale for the combination of selinexor with cisplatin or irinotecan in naïve and relapsed SCLC. The clinical availability of selinexor will allow rapid clinical translation of these results in a disease setting with extremely limited therapeutic options.

Citation Format: Alvaro Quintanal-Villalonga, Hirokazu Taniguchi, Yuan Hao, Andrew Chow, Yingqian A. Zhan, Fathema Uddin, Viola Allaj, Parvathy Manoj, Nisargbhai S. Shah, Umesh K. Bhanot, Juan Qiu, Elisa de Stanchina, Richard P. Koche, Triparna Sen, John T. Poirier, Charles M. Rudin. Exportin 1 inhibition as a therapeutic strategy for small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3594.

Abstract 658: AKT pathway as a therapeutic target to constrain lineage plasticity leading to histological transdifferentiation

Lineage plasticity contributes to therapeutic resistance in cancer. In lung adenocarcinomas (LUADs), this phenomenon drives neuroendocrine (NE) and squamous cell (LUSC) histologic transdifferentiation in the context of acquired resistance to targeted inhibition of driver mutations, with up to 14% and 9% incidences in EGFR-mutant tumors relapsed on EGFR inhibitors, respectively. Notably, survival of patients with NE- or LUSC-transdifferentiated tumors is lower than that of either LUAD or de novo LUSC patients. To date, little is known about the molecular effectors enhancing lineage plasticity and driving histological transdifferentiation due to the paucity of well annotated pre- and post-transdifferentiation clinical samples amenable for molecular analyses. Currently no specific therapies for LUSC or NE transdifferentiation prevention are available for patients at high risk of transformation.

We performed multi-omic profiling of transdifferentiating clinical samples, as well as control never-transformed LUAD and de novo LUSC and small cell carcinomas, including comprehensive and integrative genomic (whole exome sequencing), epigenomic (bisulfite sequencing), transcriptomic (RNAseq) and protein (antibody arrays) characterization. Findings were validated in preclinical models including cell lines as well as LUSC- and NE-transdifferentiation patient-derived xenograft models.

Our data suggest that histological transdifferentiation is driven by epigenetic -rather than mutational- events, and indicate that transdifferentiated tumors retain molecular features of their previous LUAD state. Integrative analysis revealed biological pathways dysregulated specifically for distinct histological outcomes, including downregulation of RTK signaling and Notch-related genes in NE-transformed tumors, and upregulation of genes involved in Hedgehog and Notch signaling and MYC targets in LUSC-transdifferentiated tumors. Most interestingly, these analyses revealed commonly dysregulated pathways for transdifferentiated tumors, including marked downregulation of a variety of immune-related pathways and upregulation of genes involved in AKT signaling and in the PRC2 epigenetic remodeling complex. Concurrent activation of AKT and MYC overexpression induced a squamous phenotype in EGFR-mutant LUAD preclinical models, further accentuated by EGFR inhibition. Pharmacological targeting of AKT in combination with osimertinib delayed both squamous and NE transformation in EGFR-mutant patient-derived xenograft transdifferentiation models.

These results identify common and histology-specific drivers and dysregulated pathways in NE and LUSC transdifferentiation, and nominate AKT as a therapeutic target to constrain lineage plasticity and prevent the acquisition of resistance to EGFR-targeted therapies through histological transdifferentiation.

Citation Format: Alvaro Quintanal-Villalonga, Hirokazu Taniguchi, Yingqian A. Zhan, Fathema Uddin, Viola Allaj, Parvathy Manoj, Nisargbhai S. Shah, Umesh K. Bhanot, Jacklynn Egger, Juan Qiu, Elisa de Stanchina, Natasha Rekhtman, Brian Houck-Loomis, Richard P. Koche, Helena A. Yu, Triparna Sen, Charles M. Rudin. AKT pathway as a therapeutic target to constrain lineage plasticity leading to histological transdifferentiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 658.

Signatures of plasticity, metastasis, and immunosuppression in an atlas of human small cell lung cancer

Small cell lung cancer (SCLC) is an aggressive malignancy that includes subtypes defined by differential expression of ASCL1, NEUROD1, and POU2F3 (SCLC-A, -N, and -P, respectively). To define the heterogeneity of tumors and their associated microenvironments across subtypes, we sequenced 155,098 transcriptomes from 21 human biospecimens, including 54,523 SCLC transcriptomes. We observe greater tumor diversity in SCLC than lung adenocarcinoma, driven by canonical, intermediate, and admixed subtypes. We discover a PLCG2-high SCLC phenotype with stem-like, pro-metastatic features that recurs across subtypes and predicts worse overall survival. SCLC exhibits greater immune sequestration and less immune infiltration than lung adenocarcinoma, and SCLC-N shows less immune infiltrate and greater T cell dysfunction than SCLC-A. We identify a profibrotic, immunosuppressive monocyte/macrophage population in SCLC tumors that is particularly associated with the recurrent, PLCG2-high subpopulation.

Comprehensive molecular characterization of lung tumors implicates AKT and MYC signaling in adenocarcinoma to squamous cell transdifferentiation

BACKGROUND

Lineage plasticity, the ability to transdifferentiate among distinct phenotypic identities, facilitates therapeutic resistance in cancer. In lung adenocarcinomas (LUADs), this phenomenon includes small cell and squamous cell (LUSC) histologic transformation in the context of acquired resistance to targeted inhibition of driver mutations. LUAD-to-LUSC transdifferentiation, occurring in up to 9% of EGFR-mutant patients relapsed on osimertinib, is associated with notably poor prognosis. We hypothesized that multi-parameter profiling of the components of mixed histology (LUAD/LUSC) tumors could provide insight into factors licensing lineage plasticity between these histologies.

METHODS

We performed genomic, epigenomics, transcriptomics and protein analyses of microdissected LUAD and LUSC components from mixed histology tumors, pre-/post-transformation tumors and reference non-transformed LUAD and LUSC samples. We validated our findings through genetic manipulation of preclinical models in vitro and in vivo and performed patient-derived xenograft (PDX) treatments to validate potential therapeutic targets in a LUAD PDX model acquiring LUSC features after osimertinib treatment.

RESULTS

Our data suggest that LUSC transdifferentiation is primarily driven by transcriptional reprogramming rather than mutational events. We observed consistent relative upregulation of PI3K/AKT, MYC and PRC2 pathway genes. Concurrent activation of PI3K/AKT and MYC induced squamous features in EGFR-mutant LUAD preclinical models. Pharmacologic inhibition of EZH1/2 in combination with osimertinib prevented relapse with squamous-features in an EGFR-mutant patient-derived xenograft model, and inhibition of EZH1/2 or PI3K/AKT signaling re-sensitized resistant squamous-like tumors to osimertinib.

CONCLUSIONS

Our findings provide the first comprehensive molecular characterization of LUSC transdifferentiation, suggesting putative drivers and potential therapeutic targets to constrain or prevent lineage plasticity.

Multi-omic analysis of lung tumors defines pathways activated in neuroendocrine transformation

Lineage plasticity is implicated in treatment resistance in multiple cancers. In lung adenocarcinomas (LUADs) amenable to targeted therapy, transformation to small cell lung cancer (SCLC) is a recognized resistance mechanism. Defining molecular mechanisms of neuroendocrine (NE) transformation in lung cancer has been limited by a paucity of pre-/post-transformation clinical samples. Detailed genomic, epigenomic, transcriptomic, and protein characterization of combined LUAD/SCLC tumors, as well as pre-/post-transformation samples, support that NE transformation is primarily driven by transcriptional reprogramming rather than mutational events. We identify genomic contexts in which NE transformation is favored, including frequent loss of the 3p chromosome arm. We observed enhanced expression of genes involved in PRC2 complex and PI3K/AKT and NOTCH pathways. Pharmacological inhibition of the PI3K/AKT pathway delayed tumor growth and NE transformation in an EGFR-mutant patient-derived xenograft model. Our findings define a novel landscape of potential drivers and therapeutic vulnerabilities of neuroendocrine transformation in lung cancer.

Pancreatic intraductal tubulopapillary neoplasm is genetically distinct from intraductal papillary mucinous neoplasm and ductal adenocarcinoma

Intraductal tubulopapillary neoplasm is a relatively recently described member of the pancreatic intraductal neoplasm family. The more common member of this family, intraductal papillary mucinous neoplasm, often carries genetic alterations typical of pancreatic infiltrating ductal adenocarcinoma (KRAS, TP53, and CDKN2A) but additionally has mutations in GNAS and RNF43 genes. However, the genetic characteristics of intraductal tubulopapillary neoplasm have not been well characterized. Twenty-two intraductal tubulopapillary neoplasms were analyzed by either targeted next-generation sequencing, which enabled the identification of sequence mutations, copy number alterations, and selected structural rearrangements involving all targeted (≥300) genes, or whole-exome sequencing. Three of these intraductal tubulopapillary neoplasms were also subjected to whole-genome sequencing. All intraductal tubulopapillary neoplasms revealed the characteristic histologic (cellular intraductal nodules of back-to-back tubular glands lined by predominantly cuboidal cells with atypical nuclei and no obvious intracellular mucin) and immunohistochemical (immunolabeled with MUC1 and MUC6 but were negative for MUC2 and MUC5AC) features. By genomic analyses, there was loss of CDKN2A in 5/20 (25%) of these cases. However, the majority of the previously reported intraductal papillary mucinous neoplasm-related alterations were absent. Moreover, in contrast to most ductal neoplasms of the pancreas, MAP-kinase pathway was not involved. In fact, 2/22 (9%) of intraductal tubulopapillary neoplasms did not reveal any mutations in the tested genes. However, certain chromatin remodeling genes (MLL1, MLL2, MLL3, BAP1, PBRM1, EED, and ATRX) were found to be mutated in 7/22 (32%) of intraductal tubulopapillary neoplasms and 27% harbored phosphatidylinositol 3-kinase (PI3K) pathway (PIK3CA, PIK3CB, INPP4A, and PTEN) mutations. In addition, 4/18 (18%) of intraductal tubulopapillary neoplasms had FGFR2 fusions (FGFR2-CEP55, FGFR2-SASS6, DISP1-FGFR2, FGFR2-TXLNA, and FGFR2-VCL) and 1/18 (5.5%) had STRN-ALK fusion. Intraductal tubulopapillary neoplasm is a distinct clinicopathologic entity in the pancreas. Although its intraductal nature and some clinicopathologic features resemble those of intraductal papillary mucinous neoplasm, our results suggest that intraductal tubulopapillary neoplasm has distinguishing genetic characteristics. Some of these mutated genes are potentially targetable. Future functional studies will be needed to determine the consequences of these gene alterations.

Abstract 2714: Analytical validation of clinical whole genome and transcriptome sequencing of patient derived tumors: clinical application of whole genome sequencing for reporting targetable variants in cancer

Next Generation DNA Sequencing (NGS) technologies are currently being applied in the clinical setting for the treatment of disease. The goal is to use high-throughput sequencing to identify specific variants within each tumor and recommend personalized treatment approaches or clinical trials tailored to the individual’s disease and genomic profile. These assays are comprised of either predefined sequencing panels, where a handpicked set of clinically significant genes are examined within each patient, or are cancer type specific targeted sequencing protocols or whole exome platforms covering only the coding region of the patient’s genome. Whole genome sequencing allows hypothesis-free interrogation of both coding and non-coding regions of the genome revealing more potential therapeutic options than examining a small set of genes or genomic loci. The protocol eliminates sequence capture related bias observed in whole exome or panel sequencing. The New York Genome Center therefore has performed analytical validation of whole genome and transcriptome sequencing (WGTS) of patient derived tumors and matched normals for the purposes of clinical testing and have devised a clinical reporting strategy of significant driver and therapeutic associated mutations. Many clinical NGS guidelines are directed toward targeted panel or exome sequencing validation. Here, we expanded on New York State’s Department of Health NGS guidelines developing them into novel standards applicable to WGTS for the purposes of clinical test validation. We first sequenced a virtual tumor at very high coverage (300x) and downsampled to determine the optimum depth of sequencing necessary for high confidence somatic variant calling across the entire genome. We then validated whole genome sequencing laboratory protocols for DNA and RNA sequencing on a total of 50 specimens derived from fresh frozen (FF) and formalin-fixed paraffin-embedded (FFPE) tumor samples. We performed a series of experiments to assess the accuracy and reliability of the results based on our laboratory and bioinformatics protocols. We performed our validation on the 50 tumor normal pairs, a subset of which had known genomic profiles. Comparisons were also made for variant calling concordance and reproducibility between matched FF and FFPE tumors. Here, we present our validation results and clinical WGTS standards for depth of sequencing, reproducibility, sensitivity, and present limit of detection analysis for SNV calling, copy number identification and structural variants. RNA sequencing is performed to call fusion or exon skipping events and to confirm the DNA variants. The New York Genome Center WGTS clinical assay is intended to provide a more comprehensive patient variant discovery approach suitable for directed oncological therapeutic applications.

Citation Format: Kazimierz O. Wrzeszczynski, Avinash Abhyankar, Vanessa Felice, Esra Dikoglu, Lukasz Kozon, Nicolas Robine, Anne-Katrin Emde, Olca Basturk, Umesh K. Bhanot, Alex Kentsis, Mahesh Mansukhani, Govind Bhagat, Vaidehi Jobanputra. Analytical validation of clinical whole genome and transcriptome sequencing of patient derived tumors: clinical application of whole genome sequencing for reporting targetable variants in cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2714. doi:10.1158/1538-7445.AM2017-2714

Combined melanocytic and sweat gland neoplasm: cell subsets harbor an identical HRAS mutation in phacomatosis pigmentokeratotica

Phacomatosis pigmentokeratotica (PPK) is characterized by the co-existence of epidermal nevi and large segmental speckled lentiginous nevi of the papulosa type. PPK, previously explained as 'twin spot' mosaicism due to the postzygotic crossing-over of two homozygous recessive mutations, has recently been shown to derive from one postzygotic activating RAS mutation. Epidermal nevi, including those in PPK, are known to give rise to neoplasms such as trichoblastoma and basal cell carcinoma. Within speckled lentiginous nevi, Spitz nevi and melanoma have been well documented. We report a case of PPK with a combined melanocytic and adnexal neoplasm presenting where the nevi conjoined. Using next-generation sequencing techniques, we were able to identify the same HRAS G13R mutation within both components of the tumor, and to show the absence of additional mutated modifier genes in a panel of 300 cancer-related genes. Given the genetic findings in this rare tumor-type, we suggest that this case may be used as a model for understanding the development of biphenotypic neoplasia or intratumoral heterogeneity in some cases.

[Parenchymal regression in chronic pancreatitis spares islets reprogrammed for expression of NFkappaB and IAPs]

In chronic pancreatitis (CP), fibrous replacement of exocrine tissue spares islets. There is local production of IFNgamma and death ligands by inflammatory cells as well as TGFbeta and TRAIL by pancreatic stellate cells (PSCs), along with functional death receptor neo-expression and apoptosis in exocrine but not in endocrine cells. Moreover, islets are strongly induced for TRAIL-receptor(R)-4 lacking a functional death domain. TRAIL-R4 signalling in T-cells induces NFkappaB transcription factors which activate anti-apoptotic programs. Whether TRAIL elicits this response in endocrine cells, we tested human insulinoma cell line CM and determined NFkappaB subunits transcripts and NFkappaB dependent inhibitor of apoptosis proteins (IAPs) in normal pancreas (NP) and CP. We treated CM with cytokines, determined TRAIL-R expression by flow cytometry, graded degree of fibrosis in CP specimens, microdissected epithelial compartments, performed real time PCRs for NFkappaB subunits transcripts, and immunohistochemistry for IKK-gamma, IkappaB-alpha, RelA, survivin, and cIAP1. In CM, TGFbeta/IFNgamma/TRAIL induced TRAIL-R4 surface expression. TRAIL/ IFNgamma, upregulated NFkappaB subunits and survivin while down-modulating 1kappaBalpha. NP epithelia had low RNA levels of NFkappaB subunits. These were increased in parenchymal areas of CP with severe fibrosis and most intensely in islets. The NFkappaB regulated proteins IkappaBalpha, survivin, and cIAP1 were found in corresponding sites, again, at highest levels in islets surrounded by fibrosis. In CP, islets not only evade immune attack by non-exposure of functional death receptors in presence of TRAIL-R4. They also neo-express NFkappaB subunits, survivin, and cIAP1. This apoptosis-inhibitory security program might be enforced by PSC-derived TRAIL.

Parenchymal regression in chronic pancreatitis spares islets reprogrammed for the expression of NFkappaB and IAPs

In advanced chronic pancreatitis (CP), islets are preserved even in the midst of scarring. We recently showed in CP local production of interferon (IFN)gamma, transforming growth factor (TGF)beta and death receptor ligand TRAIL (tumor necrosis factor-related apoptosis-inducing ligand), along with functional death receptor neoexpression and apoptosis in exocrine but not in endocrine cells. However, islets are strongly induced for TRAIL-receptor (R)-4 lacking the functional death domain. TRAIL-R4 signaling in T cells induces NFkappaB, which activates antiapoptotic programs. Here, we demonstrate that in insulinoma cells CM, TGFbeta/IFNgamma/TRAIL in combination induced TRAIL-R4 surface expression. TRAIL/IFNgamma upregulated NFkappaB subunits and its target gene survivin while downmodulating IkappaB alpha mRNA. RelA transcriptional activity increased upon stimulation with IFNgamma and IFNgamma/TRAIL. In situ, normal pancreatic epithelia had low mRNA levels of NFkappaB subunits. These were higher in parenchymal areas of CP with severe fibrosis and highest in islets. NFkappaB-regulated proteins IkappaB alpha, survivin and another apoptosis inhibitor, cIAP1, were found in corresponding sites, again at highest levels in islets surrounded by fibrosis. In conclusion, islets in CP not only evade immune attack by nonexposure of functional death receptors in the presence of TRAIL-R4 but also additionally neoexpress NFkappaB and its target genes, survivin and cIAP1, to protect themselves from apoptosis.

Prospective Study of 100 cases of Pap Smear

Abstract

THE ROLE OF FINE NEEDLE ASPIRATION CYTOLOGY (FNAC) IN THE DIAGNOSIS OF TUBERCULOSIS LYMPHADENITIS

ABSTRACT

Correlation of H. pylori density with grading of chronic gastritis

Histopathological study of endoscopic gastric mucosa obtained from 251 patients with acid peptic diseases were studied in relation to the degrees of inflammation and the degree of H. Pylori density. Haematoxylin-Eosin and modified Giemsa stains were used. Gastritis grading was done according to Warren and Marshall with slight modification and H. Pylori grading according to our criteria. In this study no definite relationship could be observed between histological grading of chronic gastritis with that of H. Pylori density.