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1.
Fed Pract ; 40(6): 186-193, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37860072

ABSTRACT

Background: Telepathology, which includes the use of telecommunication links, helps enable transmission of digital pathology images for primary diagnosis, quality assurance, education, research, or second opinion diagnoses. Observations: This review covers all aspects of telepathology implementation, including the selection of platforms, budgets and regulations, validation, implementation, education, quality monitoring, and the potential to improve practice. Considering the long-term trends, the lessons of the COVID-19 pandemic, and the potential for future pandemics or other disasters, the validation and implementation of telepathology remains a reasonable choice for laboratories looking to improve their practice. Conclusions: Though barriers to implementation exist, there are potential benefits, such as the wide spectrum of uses like frozen section, telecytology, primary diagnosis, and second opinions. Telepathology represents an innovation that may transform the future of pathology practice.

3.
Front Immunol ; 14: 1113883, 2023.
Article in English | MEDLINE | ID: mdl-36776889

ABSTRACT

Introduction: Non-alcoholic fatty liver disease (NAFLD) has a global prevalence of 25% of the population and is a leading cause of cirrhosis and hepatocellular carcinoma. NAFLD ranges from simple steatosis (non-alcoholic fatty liver) to non-alcoholic steatohepatitis (NASH). Hepatic macrophages, specifically Kupffer cells (KCs) and monocyte-derived macrophages, act as key players in the progression of NAFLD. Caspases are a family of endoproteases that provide critical connections to cell regulatory networks that sense disease risk factors, control inflammation, and mediate inflammatory cell death (pyroptosis). Caspase-11 can cleave gasdermin D (GSDMD) to induce pyroptosis and specifically defends against bacterial pathogens that invade the cytosol. However, it's still unknown whether high fat diet (HFD)-facilitated gut microbiota-generated cytoplasmic lipopolysaccharides (LPS) activate caspase-11 and promote NAFLD. Methods: To examine this hypothesis, we performed liver pathological analysis, RNA-seq, FACS, Western blots, Seahorse mitochondrial stress analyses of macrophages and bone marrow transplantation on HFD-induced NAFLD in WT and Casp11-/- mice. Results and Discussion: Our results showed that 1) HFD increases body wight, liver wight, plasma cholesterol levels, liver fat deposition, and NAFLD activity score (NAS score) in wild-type (WT) mice; 2) HFD increases the expression of caspase-11, GSDMD, interleukin-1ß, and guanylate-binding proteins in WT mice; 3) Caspase-11 deficiency decreases fat liver deposition and NAS score; 4) Caspase-11 deficiency decreases bone marrow monocyte-derived macrophage (MDM) pyroptosis (inflammatory cell death) and inflammatory monocyte (IM) surface GSDMD expression; 5) Caspase-11 deficiency re-programs liver transcriptomes and reduces HFD-induced NAFLD; 6) Caspase-11 deficiency decreases extracellular acidification rates (glycolysis) and oxidative phosphorylation (OXPHOS) in inflammatory fatty acid palmitic acid-stimulated macrophages, indicating that caspase-11 significantly contributes to maintain dual fuel bioenergetics-glycolysis and OXPHOS for promoting pyroptosis in macrophages. These results provide novel insights on the roles of the caspase-11-GSDMD pathway in promoting hepatic macrophage inflammation and pyroptosis and novel targets for future therapeutic interventions involving the transition of NAFLD to NASH, hyperlipidemia, type II diabetes, metabolic syndrome, metabolically healthy obesity, atherosclerotic cardiovascular diseases, autoimmune diseases, liver transplantation, and hepatic cancers.


Subject(s)
Diabetes Mellitus, Type 2 , Non-alcoholic Fatty Liver Disease , Mice , Animals , Non-alcoholic Fatty Liver Disease/pathology , Diet, High-Fat/adverse effects , Caspases/metabolism , Pyroptosis , Oxidative Phosphorylation , Diabetes Mellitus, Type 2/metabolism , Macrophages , Inflammation/metabolism , Glycolysis
5.
Adv Anat Pathol ; 29(6): 349-357, 2022 Nov 01.
Article in English | MEDLINE | ID: mdl-36306184

ABSTRACT

Pancreatic cysts are increasingly detected on imaging studies. Accurate determination of the type of cyst is important to provide appropriate care for patients. It is also very clear that not one single modality can provide adequate diagnostic information for pancreatic cysts. A multimodal approach to the diagnosis of pancreatic cyst is the key. This review will highlight how to approach to fine-needle aspiration of pancreatic cysts. The review will also highlight salient features of common neoplastic pancreatic cysts along with the use of ancillary testing which includes biochemical testing, commonly utilized molecular tests, and/or immunohistochemical tests to provide an accurate diagnosis.


Subject(s)
Pancreatic Cyst , Pancreatic Neoplasms , Humans , Biopsy, Fine-Needle , Pancreatic Neoplasms/diagnosis , Pancreatic Cyst/diagnosis , Immunohistochemistry
6.
Indian J Pathol Microbiol ; 65(4): 966-969, 2022.
Article in English | MEDLINE | ID: mdl-36308226

ABSTRACT

Dr. Purushottam Vishwanath Gharpure was an eminent Indian pathologist and an emeritus Professor of Pathology at the Grant Medical College, Bombay. He was a pioneer in carrying out the first field trial of polio vaccination which marked the beginning of the polio eradication program in India. Dr. Gharpure set an example by taking his laboratory work to the field and proving how the laboratory research can be used to better the society. The mesmerizing story of Dr. "Gharpure's life" is described in this paper.


Subject(s)
Pathologists , Poliomyelitis , Humans , India , Laboratories , Poliomyelitis/prevention & control , Vaccination
7.
Cytojournal ; 19: 16, 2022.
Article in English | MEDLINE | ID: mdl-35510111

ABSTRACT

Malignant effusions can occur in patients with neoplasia. Once a metastatic diagnosis is confirmed, the primary site of origin of malignancy needs to be ascertained. This task can be challenging without a prior history of malignancy. In some patients their effusion may be the initial presentation of an underlying malignancy. Metastases usually present with a dual population of mesothelial and malignant cells. Combining cytomorphologic examination with ancillary testing such as immunocytochemistry can help identify the origin of the foreign malignant cell population. Helpful architectural clues include a single cell pattern, solid cell ball pattern, single file arrangement, papillary formation, psammoma bodies and background mucin. Useful cellular features include the presence of signet ring cells, small cells, pleomorphic and multinucleated giant cells, squamous cells, spindle cells and pigmentation. Rarely, despite an extensive work-up the primary site of origin for a malignant effusion may remain unresolved. This review article will be incorporated finally as one of the chapters in CMAS (CytoJournal Monograph/Atlas Series) #2. It is modified slightly from the chapter by the initial authors in the first edition of Cytopathologic Diagnosis of Serous Fluids.

8.
Cytojournal ; 19: 14, 2022.
Article in English | MEDLINE | ID: mdl-35510119

ABSTRACT

This chapter highlights the steps that would help to analyze any fluid. It highlights importance of knowing gross analysis of fluid along with biochemical information. These parameters along with clinical information are very important in arriving at a differential diagnosis. Morphologic appearances in the fluid can often become challenging and occasionally reactive conditions can reveal changes that may mimic malignancies. This chapter provides not only a framework of approach to assessment of fluid cytology but also shows how to distinguish some of the challenging reactive conditions from the diagnosis of carcinoma. The chapter also utilizes two cases to demonstrate approach to reactive conditions. This review article will be incorporated finally as one of the chapters in CMAS (CytoJournal Monograph/Atlas Series) #2. It is modified slightly from the chapter by the initial authors in the first edition of Cytopathologic Diagnosis of Serous Fluids.

9.
J Immunol Res ; 2021: 3928323, 2021.
Article in English | MEDLINE | ID: mdl-34859106

ABSTRACT

We performed a panoramic analysis on both human nonalcoholic steatohepatitis (NASH) microarray data and microarray/RNA-seq data from various mouse models of nonalcoholic fatty liver disease NASH/NAFLD with total 4249 genes examined and made the following findings: (i) human NASH and NAFLD mouse models upregulate both cytokines and chemokines; (ii) pathway analysis indicated that human NASH can be classified into metabolic and immune NASH; methionine- and choline-deficient (MCD)+high-fat diet (HFD), glycine N-methyltransferase deficient (GNMT-KO), methionine adenosyltransferase 1A deficient (MAT1A-KO), and HFCD (high-fat-cholesterol diet) can be classified into inflammatory, SAM accumulation, cholesterol/mevalonate, and LXR/RXR-fatty acid ß-oxidation NAFLD, respectively; (iii) canonical and noncanonical inflammasomes play differential roles in the pathogenesis of NASH/NAFLD; (iv) trained immunity (TI) enzymes are significantly upregulated in NASH/NAFLD; HFCD upregulates TI enzymes more than cytokines, chemokines, and inflammasome regulators; (v) the MCD+HFD is a model with the upregulation of proinflammatory cytokines and canonical and noncanonical inflammasomes; however, the HFCD is a model with upregulation of TI enzymes and lipid peroxidation enzymes; and (vi) caspase-11 and caspase-1 act as upstream master regulators, which partially upregulate the expressions of cytokines, chemokines, canonical and noncanonical inflammasome pathway regulators, TI enzymes, and lipid peroxidation enzymes. Our findings provide novel insights on the synergies between hyperlipidemia and hypomethylation in establishing TI and promoting inflammation in NASH and NAFLD progression and novel targets for future therapeutic interventions for NASH and NAFLD, metabolic diseases, transplantation, and cancers.


Subject(s)
Hyperlipidemias/immunology , Inflammation/immunology , Animals , Caspase 1/metabolism , Caspases/metabolism , Cytokines/metabolism , Diet, High-Fat , Disease Models, Animal , Glycine N-Methyltransferase/genetics , Humans , Immunity , Inflammation Mediators/metabolism , Methionine Adenosyltransferase/genetics , Methylation , Mice , Mice, Knockout , Non-alcoholic Fatty Liver Disease
10.
Indian J Pathol Microbiol ; 64(4): 791-794, 2021.
Article in English | MEDLINE | ID: mdl-34673606

ABSTRACT

Amyloidosis is caused by an extracellular accumulation of insoluble fibrillary protein predominantly in the kidneys, spleen, and heart. The deposition of amyloid into the joints, synovia, and osseous tissues (amyloid arthropathy) is an uncommon condition with only a few case reports in the English literature. Similarly, amyloid deposition predominantly limited to the vascular wall is rarely described. In this report, we describe an additional case of amyloidosis of the hip joint along with amyloidosis of intramural coronaries leading to sudden death in a middle-aged male.


Subject(s)
Amyloidosis/mortality , Amyloidosis/pathology , Death, Sudden, Cardiac/pathology , Hip Joint/pathology , Amyloid/metabolism , Coronary Vessels/pathology , Hip Joint/diagnostic imaging , Humans , Magnetic Resonance Imaging , Male , Middle Aged
12.
Clin Gastroenterol Hepatol ; 19(4): 825-835.e7, 2021 04.
Article in English | MEDLINE | ID: mdl-32652307

ABSTRACT

BACKGROUND & AIMS: Given the lack of procedure standardization, findings vary from analyses of pancreatic tissues collected by endoscopic ultrasound-guided fine-needle biopsy. It is not clear which needle and technique yield the best specimen for analysis. We compared the specimen quality and accuracy of diagnoses made from samples collected by fine-needle biopsy needles using different collection techniques. METHODS: Patients found to have pancreatic masses during imaging (n = 129) were assigned randomly to groups from whom pancreatic tissue samples were collected by reverse-bevel, Menghini-tip, franseen, or fork-tip needles. A second randomization determined the technical sequence of biopsies in each patient (suction, no suction, and stylet retraction). Two independent pathologists, blinded to the type of needle and sampling technique, analyzed all the samples. Final diagnoses of malignancy were made based on surgical resection, death from cancer progression, or findings from radiology or clinical follow-up evaluations (reference standard). The primary objective was to compare the cellularity of the samples collected, defined as the proportion of core tissue in the biopsy sample. Secondary objectives were to compare the accuracy of diagnoses made from biopsy samples and identify factors associated with high cellularity. RESULTS: One-hundred and nine patients had a final diagnosis of malignancy (84.5%) and 20 patients had benign disease (15.5%). Samples collected by fork-tip or franseen needles had significantly higher cellularity than samples collected by reverse-bevels or Menghini-tip needles (P < .001). Neoplasias were identified with greater than 90% accuracy using samples collected by fork-tip or franseen needles (P < .001 compared with other needles). On multivariable regression analysis, use of franseen needles (odds ratio [OR], 4.42; 95% CI, 2.58-7.58; P < .001) or fork-tip needles (OR, 3.86; 95% CI, 2.24-6.64; P < .001), stylet retraction (OR, 2.13; 95% CI, 1.21-3.72; P = .008), no suction (OR, 2.74; 95% CI, 1.57-4.80; P < .001), and pancreatic mass larger than 3 cm (OR, 1.92; 95% CI, 1.21-3.05; P = .005) were associated with high cellularity of the sample. CONCLUSIONS: In patients with suspected pancreatic cancer, samples with the highest degree of cellularity in a single biopsy, resulting in a diagnostic accuracy of 90% of higher, were collected by fine-needle biopsy using the franseen or fork-tip needle. Clinicaltrials.gov no: NCT04085055.


Subject(s)
Needles , Pancreatic Neoplasms , Endoscopic Ultrasound-Guided Fine Needle Aspiration , Humans , Pancreas/diagnostic imaging , Pancreatic Neoplasms/diagnosis , Ultrasonography
13.
Front Immunol ; 11: 595813, 2020.
Article in English | MEDLINE | ID: mdl-33154757

ABSTRACT

Interleukin (IL) 35 is a novel immunosuppressive heterodimeric cytokine in IL-12 family. Whether and how IL-35 regulates ischemia-induced angiogenesis in peripheral artery diseases are unrevealed. To fill this important knowledge gap, we used loss-of-function, gain-of-function, omics data analysis, RNA-Seq, in vivo and in vitro experiments, and we have made the following significant findings: i) IL-35 and its receptor subunit IL-12RB2, but not IL-6ST, are induced in the muscle after hindlimb ischemia (HLI); ii) HLI-induced angiogenesis is improved in Il12rb2-/- mice, in ApoE-/-/Il12rb2-/- mice compared to WT and ApoE-/- controls, respectively, where hyperlipidemia inhibits angiogenesis in vivo and in vitro; iii) IL-35 cytokine injection as a gain-of-function approach delays blood perfusion recovery at day 14 after HLI; iv) IL-35 spares regenerative angiogenesis at the late phase of HLI recovery after day 14 of HLI; v) Transcriptome analysis of endothelial cells (ECs) at 14 days post-HLI reveals a disturbed extracellular matrix re-organization in IL-35-injected mice; vi) IL-35 downregulates three reactive oxygen species (ROS) promoters and upregulates one ROS attenuator, which may functionally mediate IL-35 upregulation of anti-angiogenic extracellular matrix proteins in ECs; and vii) IL-35 inhibits human microvascular EC migration and tube formation in vitro mainly through upregulating anti-angiogenic extracellular matrix-remodeling proteins. These findings provide a novel insight on the future therapeutic potential of IL-35 in suppressing ischemia/inflammation-triggered inflammatory angiogenesis at early phase but sparing regenerative angiogenesis at late phase.


Subject(s)
Hindlimb/blood supply , Interleukins/immunology , Ischemia/immunology , Receptors, Interleukin-12/immunology , Animals , Apolipoproteins E/genetics , Cell Line , Cell Movement , Extracellular Matrix/immunology , Humans , Male , Mice, Inbred C57BL , Mice, Knockout , Neovascularization, Pathologic , Neovascularization, Physiologic , Reactive Oxygen Species/immunology , Receptors, Interleukin-12/genetics
14.
Pathogens ; 9(11)2020 Oct 24.
Article in English | MEDLINE | ID: mdl-33114395

ABSTRACT

Ischemia reperfusion injury (IRI) during liver transplantation increases morbidity and contributes to allograft dysfunction. There are no therapeutic strategies to mitigate IRI. We examined a novel hypothesis: caspase 1 and caspase 11 serve as danger-associated molecular pattern (DAMPs) sensors in IRI. By performing microarray analysis and using caspase 1/caspase 11 double-knockout (Casp DKO) mice, we show that the canonical and non-canonical inflammasome regulators are upregulated in mouse liver IRI. Ischemic pre (IPC)- and post-conditioning (IPO) induce upregulation of the canonical and non-canonical inflammasome regulators. Trained immunity (TI) regulators are upregulated in IPC and IPO. Furthermore, caspase 1 is activated during liver IRI, and Casp DKO attenuates liver IRI. Casp DKO maintained normal liver histology via decreased DNA damage. Finally, the decreased TUNEL assay-detected DNA damage is the underlying histopathological and molecular mechanisms of attenuated liver pyroptosis and IRI. In summary, liver IRI induces the upregulation of canonical and non-canonical inflammasomes and TI enzyme pathways. Casp DKO attenuate liver IRI. Development of novel therapeutics targeting caspase 1/caspase 11 and TI may help mitigate injury secondary to IRI. Our findings have provided novel insights on the roles of caspase 1, caspase 11, and inflammasome in sensing IRI derived DAMPs and TI-promoted IRI-induced liver injury.

15.
Cancer Cytopathol ; 128(6): 392-402, 2020 06.
Article in English | MEDLINE | ID: mdl-32267606

ABSTRACT

BACKGROUND: Fine needle aspiration (FNA) is commonly used for the preoperative evaluation of salivary gland tumors. Tumor grade is a key factor influencing clinical management of salivary gland carcinomas (SGCs). To assess the ability to grade nonbasaloid SGCs in FNA specimens, an international panel of cytopathologists convened to review and score SGC cases. METHODS: The study cohort included 61 cases of primary SGC from the pathology archives of 3 tertiary medical centers. Cases from 2005 to 2016 were selected, scanned, and digitized. Nineteen cytopathologists blinded to the histologic diagnosis reviewed the digitized cytology slides and graded them as low, high, or indeterminate. The panelists' results were then compared to the tumor grades based on histopathologic examination of the corresponding resection specimens. RESULTS: All but 2 of the 19 (89.5%) expert panelists review more than 20 salivary gland FNAs per year; 16 (84.2%) of the panelists work at academic medical centers, and 13 (68.4%) have more than 10 years' experience. Participants had an overall accuracy of 89.4% in the grading of SGC cases, with 90.2% and 88.3% for low- and high-grade SGC, respectively. Acinic cell carcinoma and mucoepidermoid carcinoma had the highest degree of accuracy, while epithelial-myoepithelial carcinoma and salivary duct carcinoma had the lowest degree of accuracy. As expected, the intermediate-grade SGC cases showed the greatest variability (high-grade, 42.1%; low-grade, 37.5%, indeterminate, 20.4%). CONCLUSION: This study confirms the high accuracy of cytomorphologic grading of primary SGC by FNA as low- or high-grade. However, caution should be exercised when a grade cannot be confidently assigned.


Subject(s)
Cytodiagnosis/methods , Pathologists/statistics & numerical data , Salivary Gland Neoplasms/pathology , Salivary Glands/pathology , Biopsy, Fine-Needle , Cohort Studies , Humans , International Cooperation , Neoplasm Grading , Pathology, Clinical/methods , Reproducibility of Results , Salivary Gland Neoplasms/diagnosis , Sensitivity and Specificity
16.
Acta Cytol ; 64(1-2): 124-135, 2020.
Article in English | MEDLINE | ID: mdl-31509835

ABSTRACT

Pancreatic cysts are increasingly detected on imaging studies. Accurate determination of the cyst type is important to provide appropriate care for the patients. It is also very clear that not one single modality can provide adequate diagnostic information. A multidisciplinary approach is the key to the diagnosis of pancreatic cysts. In this setting, the role of ancillary testing, which includes biochemical testing (carcinoembryonic antigen and amylase levels in the cyst), molecular testing (e.g., KRAS, GNAS, VHL, and CTNB1), and/or immunohistochemical tests are very important to obtain an accurate diagnosis. This review will discuss helpful ancillary tests in common pancreatic cyst neoplasms and how to approach the diagnosis of pancreatic cysts.


Subject(s)
Carcinoma, Pancreatic Ductal/diagnosis , Endoscopic Ultrasound-Guided Fine Needle Aspiration/methods , Pancreatic Cyst/diagnosis , Pancreatic Neoplasms/diagnosis , Carcinoembryonic Antigen/metabolism , Carcinoma, Pancreatic Ductal/genetics , Carcinoma, Pancreatic Ductal/metabolism , DNA Mutational Analysis/methods , Humans , Immunohistochemistry/methods , Mutation , Pancreatic Cyst/genetics , Pancreatic Cyst/metabolism , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/metabolism , Proto-Oncogene Proteins p21(ras)/genetics
17.
Adv Anat Pathol ; 26(5): 292-312, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31274508

ABSTRACT

Celiac disease is a gluten-triggered immune-mediated disorder, characterized by inflammation of the enteric mucosa following lymphocytic infiltration and eventually resulting in villous blunting. There have been many developments in refining diagnostic laboratory tests for celiac disease in the last decade. Biopsy-sparing diagnostic guidelines have been proposed and validated in a few recent prospective studies. However, despite these developments, histologic evaluation of duodenal mucosa remains one of the most essential diagnostic tools as it helps in the diagnosis of celiac disease in individuals who do not fulfill the biopsy-sparing diagnostic criteria and in those not responding to a gluten-free diet. Histologic evaluation also allows for the assessment of mucosal recovery after treatment and in the identification of concurrent intestinal diseases. Therefore, pathologists should be familiar with the histologic spectrum of celiac disease and need to be aware of other disorders with similar symptoms and histopathology that may mimic celiac disease. This review aims to provide pathologists with updates on celiac laboratory testing, biopsy-sparing diagnostic criteria, histopathology, complications, and differential diagnoses of celiac disease.


Subject(s)
Celiac Disease/diagnosis , Celiac Disease/pathology , Duodenum/pathology , Glutens/metabolism , Intestinal Mucosa/pathology , Biopsy , Diagnosis, Differential , Humans
19.
Arch Pathol Lab Med ; 143(8): 1012-1021, 2019 08.
Article in English | MEDLINE | ID: mdl-30702333

ABSTRACT

CONTEXT.­: Recent studies and a few reviews suggest that presence of invasive cribriform lesions (ICLs) in prostatic acinar adenocarcinoma correlates with adverse outcomes. However, a systematic review with meta-analysis on this correlation is currently lacking. OBJECTIVE.­: To compare the likelihood of adverse outcomes by the status of ICLs in prostatic acinar adenocarcinoma with the meta-analysis of high-quality published data and institutional experience. DATA SOURCES.­: PubMed, Scopus, manually searched references, and institutional data. STUDY SELECTION.­: Observational retrospective case-control studies or prospective cohort studies of adverse outcomes stratified by the status of ICLs were selected. DATA EXTRACTION.­: Study quality was analyzed. The prevalence of adverse outcomes stratified by the status of ICLs was extracted. CONCLUSIONS.­: Eighty-five cases were reviewed. Extraprostatic extension, seminal vesicle invasion, and regional lymph node metastasis were observed in 18 (45%), 14 (35%), and 7 (17.5%) of the 40 cases with cribriform lesions, respectively. These features were observed in 4 (8.9%), 1 (2.2%), and 0 (0%) of the 45 cases without ICLs. During the follow-up, biochemical prostate-specific antigen recurrence, local recurrence, and metastasis/disease-specific death were documented in 7 (17.5%), 2 (5%), and 2 (5%) of the 40 cases with ICLs. These poor outcomes were found in 6 (13.3%), 1 (2.2%), and 1 (2.2%) of the 45 cases without ICLs. Meta-analysis revealed a significant increase in the risk of adverse outcomes in patients who had ICLs relative to those who did not (odds ratio, 3.95; 95% CI, 2.61-5.97; I2 = 53%; Z = 6.52; P < .01). These results suggest that presence of ICLs is associated with adverse outcomes.


Subject(s)
Adenocarcinoma/pathology , Prostatic Neoplasms/pathology , Aged , Humans , Male , Middle Aged , Neoplasm Invasiveness , Neoplasm Recurrence, Local , Prospective Studies , Retrospective Studies
20.
Int J Cancer ; 145(2): 474-483, 2019 07 15.
Article in English | MEDLINE | ID: mdl-30614530

ABSTRACT

The poly(ADP-ribose) polymerases (PARP) play important roles in repairing damaged DNA during intrinsic cell death. We recently linked PARP-1 to death receptor (DR)-activated extrinsic apoptosis, the present studies sought to elucidate the function of cytoplasmic PARP-1 in pancreatic cancer tumorigenesis and therapy. Using human normal and pancreatic cancer tissues, we analyzed the prevalence of cytoplasmic PARP-1 expression. In normal human pancreatic tissues, PARP-1 expression was present in the nucleus; however, cytoplasmic PARP-1 expression was identified in pancreatic cancers. Therefore, cytoplasmic PARP-1 mutants were generated by site-direct mutagenesis, to determine a causative effect of cytoplasmic PARP-1 on pancreatic cancer tumorigenesis and sensitivity to therapy with TRA-8, a humanized DR5 antibody. PARP-1 cytoplasmic mutants rendered TRA-8 sensitive pancreatic cancer cells, BxPc-3 and MiaPaCa-2, more resistant to TRA-8-induced apoptosis; whereas wild-type PARP-1, localizing mainly in the nucleus, had no effects. Additionally, cytoplasmic PARP-1, but not wild-type PARP-1, increased resistance of BxPc-3 cells to TRA-8 therapy in a mouse xenograft model in vivo. Inhibition of PARP enzymatic activity attenuated cytoplasmic PARP-1-mediated TRA-8 resistance. Furthermore, increased cytoplasmic PARP-1, but not wild-type PARP-1, was recruited into the TRA-8-activated death-inducing signaling complex and associated with increased and sustained activation of Src-mediated survival signals. In contrast, PARP-1 knockdown inhibited Src activation. Taken together, we have identified a novel function and mechanism underlying cytoplasmic PARP-1, distinct from nuclear PARP-1, in regulating DR5-activated apoptosis. Our studies support an innovative application of available PARP inhibitors or new cytoplasmic PARP-1 antagonists to enhance TRAIL therapy for TRAIL-resistant pancreatic cancers.


Subject(s)
Cytoplasm/metabolism , Drug Resistance, Neoplasm , Pancreatic Neoplasms/pathology , Poly (ADP-Ribose) Polymerase-1/genetics , Poly (ADP-Ribose) Polymerase-1/metabolism , Receptors, TNF-Related Apoptosis-Inducing Ligand/metabolism , Animals , Antibodies, Monoclonal/pharmacology , Cell Nucleus/metabolism , Cell Proliferation/drug effects , Cell Survival/drug effects , Drug Resistance, Neoplasm/drug effects , Gene Expression Regulation, Neoplastic , Humans , Male , Mice , Mutagenesis, Site-Directed , Neoplasm Grading , Neoplasm Transplantation , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/metabolism , Phenanthrenes/pharmacology , Poly (ADP-Ribose) Polymerase-1/antagonists & inhibitors , Receptors, TNF-Related Apoptosis-Inducing Ligand/antagonists & inhibitors , Signal Transduction/drug effects , Up-Regulation/drug effects
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