Abstract Background Oesophageal cancer is the sixth leading cause of cancer-related mortality wit... more Abstract Background Oesophageal cancer is the sixth leading cause of cancer-related mortality with more than 90% of oesophageal cancer being squamous cell carcinomas (ESCC) in Asian countries. Prognosis of ESCC remains extremely poor and identification of better prognostic factors is an unmet need. Methods We investigated the immune- histochemical expression of Notch1, Notch2, Notch 3, HES-1 (Hairy enhancer of Split -1) (a downstream transcription factor) and p21 among ESCC and non-tumour controls. Non-tumour controls consisted of diagnostic biopsies of GERD patients in which Barrett’s and erosive esophagitis had been ruled out. We also investigated the association of these markers with clinico-pathological features and survival. We included 46 patients of ESCC and 42 controls. IHC markers were performed according to the standard guidelines and analysed with a semi-quantitative H –score (The H score was calculated as: H score= D X I with values ranging from 1-15). Results The median age was 60 (37-78 years). M:F ratio was 30: 16. 65.2 % were smokers and 19.6 % were tobacco chewers. 38 cases were locally advanced (Stage III) and 8 were metastatic at baseline. Palliative intent therapy was offered to 24 % and definitive therapy to 76%. An ECOG -PS of 1,2 and 3 was observed in 26, 16 and 4 patients respectively. At a median follow up of 50.67 months, the median overall survival was10.47 mon (range= 8.23-15.1) mon. Using a cut-off score of 7.5 to define positivity, NOTCH 1,2,3 as well as p21 were found to be significantly over-expressed in ESCC as compared to normal controls, while there was no difference in Hes1 expression. Location, grade, baseline metastases, duration of symptoms showed no association with NOTCH 1,2 or 3 positivity. On univariate analysis, male sex, age >60 years, smokers, ECOG-PS>1, Notch 3 H score was found significant. On multivariate analysis, smokers (HR = 3.53, p = 0.013), ECOG-PS>1 (HR = 2.88, p = 0.006) and Notch3 H score (HR = 2.38, p = 0.047) emerged as independent adverse prognostic factors. Conclusions NOTCH 1,2 and 3 are highly expressed in ESCC as compared to controls. Notch3 H score is an independent predictor of survival in ESCC and merits evaluation in larger studies. Legal entity responsible for the study Raja Pramanik. Funding Intramural Research Fund, Research Section, All India Institute of Medical Sciences, New Delhi. Disclosure All authors have declared no conflicts of interest.
Background: H. pylori-associated gastritis in patients from the high-altitude area of Ladakh show... more Background: H. pylori-associated gastritis in patients from the high-altitude area of Ladakh showed severe gastritis, mucosal nodularity, atrophy, and cancer in comparison to those from North India. This study served to analyze if differences in the H. pylori virulence genotypes decide the extent of gastric mucosal inflammation. Methods: Fifty gastric biopsies each from patients with H. pylori-associated gastritis from Ladakh and a tertiary care center in North India were included. The presence of H. pylori strain was confirmed with Warthin starry stain and polymerase chain amplification of the H. pylori-specific 16S rRNA. The cagA, vacA s1, s2, and m1, m2 alleles, and dupA virulence genotypes were studied in all archival samples, followed by their histological correlations. Results: cagA (P 0.009) and vacAs1 m1 (P 0.009) genes were distinctly more in H. pylori strains colonizing the biopsies of North Indian patients. In contrast, the cagA -ve vacAs2 m2 strains were significantly more in H. pylori strain colonizing the biopsies from Ladakhi patients. dupA genotype was almost similarly present in strains from both regions. Among these, only cagA and dupA virulence genes were associated with severe mucosal neutrophilic activity and deep infiltration of H. pylori strains in North Indian patients. Conclusions: Differences in virulence genotypes of H. pylori in gastric biopsies from North Indian and Ladakhi patients were found not significant in deciding the severity of H. pylori-associated gastritis.
Background and Aim In patients with liver disease, etiology and body mass index (BMI) affects con... more Background and Aim In patients with liver disease, etiology and body mass index (BMI) affects controlled attenuation parameter (CAP) assessment using FibroScan. We aimed to assess the performance characteristics of CAP for hepatic steatosis in patients with non-alcoholic fatty liver disease (NAFLD) stratified into obese (BMI ≥ 30 kg/m 2 ) and non-obese (BMI < 30 kg/m 2 ) subgroups. Methods In this prospective study, 219 consecutive adult NAFLD patients, with an available FibroScan value (liver stiffness measurement—[LSM] and CAP) and liver biopsy, were included. Receiver operating characteristic curves were used for assessment of the CAP cut-off values predicting different stages of hepatic steatosis. Results The mean ± standard deviation age of patients was 39.7 ± 10.5 years, 116 (53%) were males, and median (interquartile range) BMI was 31.8 (25.7–43.8) kg/m 2 . One hundred (45.7%) and 119 (54.3%) patients were non-obese and obese, respectively. The median values of CAP and LSM were significantly higher among obese patients as compared with the non-obese ones: 333 (304–368) vs. 320 (296–345) dB/m, p = 0.002 and 8.3 (6.1–11.4) vs. 6.6 (5.7–10.3) kPa, p = 0.012, respectively. Among non-obese NAFLD, optimal CAP cut-off values for steatosis (S) ≥ S1, ≥ S2, and ≥ S3 were 275 dB/m, 319 dB/m, and 337 dB/m, respectively. The corresponding CAP values among obese patients were higher as 285 dB/m, 340 dB/m, and 355 dB/m, respectively. BMI independently predicted CAP on multivariate analysis. The discordance of 2-grades between CAP and biopsy measured steatosis was seen in 13% in non-obese and 19.3% in obese NAFLD. CAP overestimated steatosis more often than underestimating it, with a higher proportion in obese NAFLD. Conclusion In patients with NAFLD, interpretation of CAP requires consideration of BMI.
Background and Aims: Current evidence lay emphasis on detection of clinically significant portal ... more Background and Aims: Current evidence lay emphasis on detection of clinically significant portal hypertension rather than Varices needing treatment(VNTs) as a decision to start beta-blockers. Esophageal varices (EVs) irrespective of their size are the most reliable indicator of CSPH. While non-invasive tools (NITs) accurately identify those with VNTs, their role to identify any EVs in patients with compensated advanced liver disease(cACLD) is not known. Methods: Patients with cACLD with reliable liver stiffness measurement(LSM), blood parameters and gastroscopy were retrospectively recruited from multinational cohorts. Performance of Baveno-VI (LSM > 20kPa or platelet < 150,000/mm3) and expanded Baveno-VI criteria(LSM > 25kPa or platelet < 110,000/mm3) was assessed to detect VNTs as well as any EVs. This performance was compared with Baveno-VII possible CSPH criteria (LSM ³ 15 kPa and platelet ≤ 150000/mm3) to evaluate its utility to detect any EVs. Result: Patients with...
Background: Hepatocellular carcinoma (HCC) occurs in the majority of patients with underlying chr... more Background: Hepatocellular carcinoma (HCC) occurs in the majority of patients with underlying chronic liver disease (CLD) of viral and non-viral etiologies, which requires screening for early HCC diagnosis. Liquid biopsy holds great promise now for early detection, prognosis, and assessment of response to cancer therapy. Cell-free DNA (cfDNA) as a liquid biopsy marker can be easily detected by a real-time quantitative PCR (RT-qPCR) assay for a change in its concentration, integrity, and fragmentation in cancer.Methods: Patients with HCC (n = 100), CLD (n = 100), and healthy (n = 30) controls were included in the study. The cfDNA was isolated from serum and real-time quantitative PCR (RT-qPCR) was carried out using primer pairs for large (>205 bp) and small (110 bp) fragments of repetitive elements (ALU and LINE1) and housekeeping genes (β-Actin and GAPDH). Total cfDNA concentrations and integrity index were determined by the absolute quantitation method (L/S ratio or cfDII-integr...
MARCH7 is an E3 ubiquitin ligase known to regulate neuronal development, T-cell proliferation, an... more MARCH7 is an E3 ubiquitin ligase known to regulate neuronal development, T-cell proliferation, and cell and tissue differentiation. But, the altered expression of MARCH7 has been observed in various malignancies. Herein, the cellular localization and role of MARCH7have been elucidated in esophageal squamous cell carcinoma (ESCC), the information regarding which is currently limited. To check the expression of MARCH7 and its correlation with immune cells infiltration in ESCC, immunohistochemical analysis was performed. RNAi approach was used to investigate the role of MARCH7 in esophagealcancer cells. Interestingly, we found a significantly higher expression of MARCH7 protein in 84% of ESCC tissues than in distant matched non-malignant tissues (p ≤ 0.001). In addition to this, immunohistochemistry results have shown a negative correlation between MARCH7 protein expression and tumor-infiltrating immune cells such as CD8 + T cells (r=-0.667, p = 0.035) and PD1 + T cells (r=-0.509, p = ...
Journal of Clinical and Experimental Hepatology, 2021
Background Tight junction proteins (TJPs) play an important role in gut-barrier dysfunction in ci... more Background Tight junction proteins (TJPs) play an important role in gut-barrier dysfunction in cirrhosis and its complications such as acute variceal bleed (AVB). However, the dynamics of TJPs expression after AVB, its relation to bacterial translocation, and impact on clinical outcome is largely unknown. Aims The aim of this study was to study the expression of TJPs in cirrhosis and assess its dynamic changes in AVB. In addition, the relation of TJP expression to endotoxemia and clinical outcomes was assessed. Methods In this prospective pilot study, 17 patients of cirrhosis with AVB, 59 patients of cirrhosis without AVB (non-AVB cirrhosis), and 20 controls were assessed for claudin-2 and claudin-4 expression in the duodenal biopsy. In the AVB-cirrhosis group, additional biopsies were obtained after 3 weeks. Endotoxemia was assessed by measuring IgG anti-endotoxin antibody levels. Claudin expression was correlated with a 6-month survival. Results Claudin-2 expression was downregulated in patients with AVB and non-AVB cirrhosis in villi (P < 0.001 and 0.013) and crypts (P < 0.001 and 0.012), respectively, compared with the controls. Claudin-4 expression was similar in villi (P = 0.079), but lower in crypts (P = 0.007) in patients with cirrhosis. Claudin-2 expression was upregulated on serial biopsies in both villi and crypts (P = 0.003 and 0.001, respectively) in AVB-cirrhosis with postbleed expression comparable with those with non-AVB cirrhosis. IgG anti-endotoxin antibody levels were elevated in cirrhosis with no correlation with claudin-2/4 expression. Claudin-2 expression independently predicted survival at 6 months. Conclusion Both claudin-2 and claudin-4 expression are downregulated in cirrhosis. AVB is associated with dynamic changes in TJPs expression. Gut-barrier dysfunction might predict outcomes independent of bacterial endotoxemia in cirrhosis.
Indian Journal of Pathology and Microbiology, 2021
Background: Aggressive pancreatobiliary tumors often require oxaliplatin-based therapies, instead... more Background: Aggressive pancreatobiliary tumors often require oxaliplatin-based therapies, instead of standard gemcitabine-based therapy and biomarker studies at diagnosis to decide the appropriate therapeutic regimen. The ribonucleotide Reductase catalytic subunit M1 (RRM1) and excision repair cross-complementing gene-1 (ERCC1) are related to DNA synthesis and repair and essential in this regard. However, apart from the therapeutic benefit, their prognostic implication is controversial. Methods: In this retrospective study, paraffin-embedded tissue from 51 cases of pancreatic cancer and 29 cases of cholangiocarcinoma were evaluated for RRM1 and ERCC1 expression by immunohistochemical technique along with 18 control pancreatic and biliary tissues. The semiquantitatively H score was calculated based on stain distribution and stain intensities. Results: Both RRM1 and ERCC1 expression were high in tumor epithelium than in controls (RRM1: the difference was statistically significant in c...
MARCH8 is an E3 ligase, primarily involved in immune-modulation. Recently, we reported its aberra... more MARCH8 is an E3 ligase, primarily involved in immune-modulation. Recently, we reported its aberrant expression in human esophageal squamous cell carcinoma. However, exact mechanisms by which it regulates cancer have been poorly understood. We applied high-throughput quantitative proteomics approach to identify downstream protein targets of MARCH8. Silencing of endogenous MARCH8 in ESCC cells followed by LC-MS/MS analysis led to identification of 1029 unique proteins showing altered expression post MARCH8 knockdown. Several previously reported MARCH8 target proteins viz. TFR1, syntaxin-4, e-cadherin and CD44 were found to be upregulated. Furthermore, new putative targets of MARCH8, including β2M, were identified in the present study. We demonstrated that MARCH8 interacts with and ubiquitinates CDH1 and β2M. Inhibiting proteasome activity with MG132 prevented CDH1 and β2M degradation, indicating that MARCH8 might be targeting CDH1 and β2M for proteasomal degradation. Further, loss of β2M and CDH1 expression significantly and inversely correlated with MARCH8 expression in ESCC tissues (r = -0.737 and - 0.651, respectively; p < 0.01). In conclusion, our present study has led to identification of new targets of MARCH8 and suggests the role of MARCH8 in regulating CDH1 and β2M turnover in esophageal cancer cells. SIGNIFICANCE: The use of quantitative proteomics carried out has led to the recognition of new targets of MARCH8. The present study gives a broad understanding of the molecular remodeling arising in the ESCC after MARCH8 knockdown. The study also solidifies the idea that role of MARCH8 is not just limited to immunomodulation as silencing of MARCH8 affects various other processes such as protein processing and localization. This study might help in understanding the regulation of MARCH8 in ESCCs and the mechanism by which MARCH8 might be facilitating cancer cells to evade immune surveillance.
Abstract Background Oesophageal cancer is the sixth leading cause of cancer-related mortality wit... more Abstract Background Oesophageal cancer is the sixth leading cause of cancer-related mortality with more than 90% of oesophageal cancer being squamous cell carcinomas (ESCC) in Asian countries. Prognosis of ESCC remains extremely poor and identification of better prognostic factors is an unmet need. Methods We investigated the immune- histochemical expression of Notch1, Notch2, Notch 3, HES-1 (Hairy enhancer of Split -1) (a downstream transcription factor) and p21 among ESCC and non-tumour controls. Non-tumour controls consisted of diagnostic biopsies of GERD patients in which Barrett’s and erosive esophagitis had been ruled out. We also investigated the association of these markers with clinico-pathological features and survival. We included 46 patients of ESCC and 42 controls. IHC markers were performed according to the standard guidelines and analysed with a semi-quantitative H –score (The H score was calculated as: H score= D X I with values ranging from 1-15). Results The median age was 60 (37-78 years). M:F ratio was 30: 16. 65.2 % were smokers and 19.6 % were tobacco chewers. 38 cases were locally advanced (Stage III) and 8 were metastatic at baseline. Palliative intent therapy was offered to 24 % and definitive therapy to 76%. An ECOG -PS of 1,2 and 3 was observed in 26, 16 and 4 patients respectively. At a median follow up of 50.67 months, the median overall survival was10.47 mon (range= 8.23-15.1) mon. Using a cut-off score of 7.5 to define positivity, NOTCH 1,2,3 as well as p21 were found to be significantly over-expressed in ESCC as compared to normal controls, while there was no difference in Hes1 expression. Location, grade, baseline metastases, duration of symptoms showed no association with NOTCH 1,2 or 3 positivity. On univariate analysis, male sex, age >60 years, smokers, ECOG-PS>1, Notch 3 H score was found significant. On multivariate analysis, smokers (HR = 3.53, p = 0.013), ECOG-PS>1 (HR = 2.88, p = 0.006) and Notch3 H score (HR = 2.38, p = 0.047) emerged as independent adverse prognostic factors. Conclusions NOTCH 1,2 and 3 are highly expressed in ESCC as compared to controls. Notch3 H score is an independent predictor of survival in ESCC and merits evaluation in larger studies. Legal entity responsible for the study Raja Pramanik. Funding Intramural Research Fund, Research Section, All India Institute of Medical Sciences, New Delhi. Disclosure All authors have declared no conflicts of interest.
Background: H. pylori-associated gastritis in patients from the high-altitude area of Ladakh show... more Background: H. pylori-associated gastritis in patients from the high-altitude area of Ladakh showed severe gastritis, mucosal nodularity, atrophy, and cancer in comparison to those from North India. This study served to analyze if differences in the H. pylori virulence genotypes decide the extent of gastric mucosal inflammation. Methods: Fifty gastric biopsies each from patients with H. pylori-associated gastritis from Ladakh and a tertiary care center in North India were included. The presence of H. pylori strain was confirmed with Warthin starry stain and polymerase chain amplification of the H. pylori-specific 16S rRNA. The cagA, vacA s1, s2, and m1, m2 alleles, and dupA virulence genotypes were studied in all archival samples, followed by their histological correlations. Results: cagA (P 0.009) and vacAs1 m1 (P 0.009) genes were distinctly more in H. pylori strains colonizing the biopsies of North Indian patients. In contrast, the cagA -ve vacAs2 m2 strains were significantly more in H. pylori strain colonizing the biopsies from Ladakhi patients. dupA genotype was almost similarly present in strains from both regions. Among these, only cagA and dupA virulence genes were associated with severe mucosal neutrophilic activity and deep infiltration of H. pylori strains in North Indian patients. Conclusions: Differences in virulence genotypes of H. pylori in gastric biopsies from North Indian and Ladakhi patients were found not significant in deciding the severity of H. pylori-associated gastritis.
Background and Aim In patients with liver disease, etiology and body mass index (BMI) affects con... more Background and Aim In patients with liver disease, etiology and body mass index (BMI) affects controlled attenuation parameter (CAP) assessment using FibroScan. We aimed to assess the performance characteristics of CAP for hepatic steatosis in patients with non-alcoholic fatty liver disease (NAFLD) stratified into obese (BMI ≥ 30 kg/m 2 ) and non-obese (BMI < 30 kg/m 2 ) subgroups. Methods In this prospective study, 219 consecutive adult NAFLD patients, with an available FibroScan value (liver stiffness measurement—[LSM] and CAP) and liver biopsy, were included. Receiver operating characteristic curves were used for assessment of the CAP cut-off values predicting different stages of hepatic steatosis. Results The mean ± standard deviation age of patients was 39.7 ± 10.5 years, 116 (53%) were males, and median (interquartile range) BMI was 31.8 (25.7–43.8) kg/m 2 . One hundred (45.7%) and 119 (54.3%) patients were non-obese and obese, respectively. The median values of CAP and LSM were significantly higher among obese patients as compared with the non-obese ones: 333 (304–368) vs. 320 (296–345) dB/m, p = 0.002 and 8.3 (6.1–11.4) vs. 6.6 (5.7–10.3) kPa, p = 0.012, respectively. Among non-obese NAFLD, optimal CAP cut-off values for steatosis (S) ≥ S1, ≥ S2, and ≥ S3 were 275 dB/m, 319 dB/m, and 337 dB/m, respectively. The corresponding CAP values among obese patients were higher as 285 dB/m, 340 dB/m, and 355 dB/m, respectively. BMI independently predicted CAP on multivariate analysis. The discordance of 2-grades between CAP and biopsy measured steatosis was seen in 13% in non-obese and 19.3% in obese NAFLD. CAP overestimated steatosis more often than underestimating it, with a higher proportion in obese NAFLD. Conclusion In patients with NAFLD, interpretation of CAP requires consideration of BMI.
Background and Aims: Current evidence lay emphasis on detection of clinically significant portal ... more Background and Aims: Current evidence lay emphasis on detection of clinically significant portal hypertension rather than Varices needing treatment(VNTs) as a decision to start beta-blockers. Esophageal varices (EVs) irrespective of their size are the most reliable indicator of CSPH. While non-invasive tools (NITs) accurately identify those with VNTs, their role to identify any EVs in patients with compensated advanced liver disease(cACLD) is not known. Methods: Patients with cACLD with reliable liver stiffness measurement(LSM), blood parameters and gastroscopy were retrospectively recruited from multinational cohorts. Performance of Baveno-VI (LSM > 20kPa or platelet < 150,000/mm3) and expanded Baveno-VI criteria(LSM > 25kPa or platelet < 110,000/mm3) was assessed to detect VNTs as well as any EVs. This performance was compared with Baveno-VII possible CSPH criteria (LSM ³ 15 kPa and platelet ≤ 150000/mm3) to evaluate its utility to detect any EVs. Result: Patients with...
Background: Hepatocellular carcinoma (HCC) occurs in the majority of patients with underlying chr... more Background: Hepatocellular carcinoma (HCC) occurs in the majority of patients with underlying chronic liver disease (CLD) of viral and non-viral etiologies, which requires screening for early HCC diagnosis. Liquid biopsy holds great promise now for early detection, prognosis, and assessment of response to cancer therapy. Cell-free DNA (cfDNA) as a liquid biopsy marker can be easily detected by a real-time quantitative PCR (RT-qPCR) assay for a change in its concentration, integrity, and fragmentation in cancer.Methods: Patients with HCC (n = 100), CLD (n = 100), and healthy (n = 30) controls were included in the study. The cfDNA was isolated from serum and real-time quantitative PCR (RT-qPCR) was carried out using primer pairs for large (>205 bp) and small (110 bp) fragments of repetitive elements (ALU and LINE1) and housekeeping genes (β-Actin and GAPDH). Total cfDNA concentrations and integrity index were determined by the absolute quantitation method (L/S ratio or cfDII-integr...
MARCH7 is an E3 ubiquitin ligase known to regulate neuronal development, T-cell proliferation, an... more MARCH7 is an E3 ubiquitin ligase known to regulate neuronal development, T-cell proliferation, and cell and tissue differentiation. But, the altered expression of MARCH7 has been observed in various malignancies. Herein, the cellular localization and role of MARCH7have been elucidated in esophageal squamous cell carcinoma (ESCC), the information regarding which is currently limited. To check the expression of MARCH7 and its correlation with immune cells infiltration in ESCC, immunohistochemical analysis was performed. RNAi approach was used to investigate the role of MARCH7 in esophagealcancer cells. Interestingly, we found a significantly higher expression of MARCH7 protein in 84% of ESCC tissues than in distant matched non-malignant tissues (p ≤ 0.001). In addition to this, immunohistochemistry results have shown a negative correlation between MARCH7 protein expression and tumor-infiltrating immune cells such as CD8 + T cells (r=-0.667, p = 0.035) and PD1 + T cells (r=-0.509, p = ...
Journal of Clinical and Experimental Hepatology, 2021
Background Tight junction proteins (TJPs) play an important role in gut-barrier dysfunction in ci... more Background Tight junction proteins (TJPs) play an important role in gut-barrier dysfunction in cirrhosis and its complications such as acute variceal bleed (AVB). However, the dynamics of TJPs expression after AVB, its relation to bacterial translocation, and impact on clinical outcome is largely unknown. Aims The aim of this study was to study the expression of TJPs in cirrhosis and assess its dynamic changes in AVB. In addition, the relation of TJP expression to endotoxemia and clinical outcomes was assessed. Methods In this prospective pilot study, 17 patients of cirrhosis with AVB, 59 patients of cirrhosis without AVB (non-AVB cirrhosis), and 20 controls were assessed for claudin-2 and claudin-4 expression in the duodenal biopsy. In the AVB-cirrhosis group, additional biopsies were obtained after 3 weeks. Endotoxemia was assessed by measuring IgG anti-endotoxin antibody levels. Claudin expression was correlated with a 6-month survival. Results Claudin-2 expression was downregulated in patients with AVB and non-AVB cirrhosis in villi (P < 0.001 and 0.013) and crypts (P < 0.001 and 0.012), respectively, compared with the controls. Claudin-4 expression was similar in villi (P = 0.079), but lower in crypts (P = 0.007) in patients with cirrhosis. Claudin-2 expression was upregulated on serial biopsies in both villi and crypts (P = 0.003 and 0.001, respectively) in AVB-cirrhosis with postbleed expression comparable with those with non-AVB cirrhosis. IgG anti-endotoxin antibody levels were elevated in cirrhosis with no correlation with claudin-2/4 expression. Claudin-2 expression independently predicted survival at 6 months. Conclusion Both claudin-2 and claudin-4 expression are downregulated in cirrhosis. AVB is associated with dynamic changes in TJPs expression. Gut-barrier dysfunction might predict outcomes independent of bacterial endotoxemia in cirrhosis.
Indian Journal of Pathology and Microbiology, 2021
Background: Aggressive pancreatobiliary tumors often require oxaliplatin-based therapies, instead... more Background: Aggressive pancreatobiliary tumors often require oxaliplatin-based therapies, instead of standard gemcitabine-based therapy and biomarker studies at diagnosis to decide the appropriate therapeutic regimen. The ribonucleotide Reductase catalytic subunit M1 (RRM1) and excision repair cross-complementing gene-1 (ERCC1) are related to DNA synthesis and repair and essential in this regard. However, apart from the therapeutic benefit, their prognostic implication is controversial. Methods: In this retrospective study, paraffin-embedded tissue from 51 cases of pancreatic cancer and 29 cases of cholangiocarcinoma were evaluated for RRM1 and ERCC1 expression by immunohistochemical technique along with 18 control pancreatic and biliary tissues. The semiquantitatively H score was calculated based on stain distribution and stain intensities. Results: Both RRM1 and ERCC1 expression were high in tumor epithelium than in controls (RRM1: the difference was statistically significant in c...
MARCH8 is an E3 ligase, primarily involved in immune-modulation. Recently, we reported its aberra... more MARCH8 is an E3 ligase, primarily involved in immune-modulation. Recently, we reported its aberrant expression in human esophageal squamous cell carcinoma. However, exact mechanisms by which it regulates cancer have been poorly understood. We applied high-throughput quantitative proteomics approach to identify downstream protein targets of MARCH8. Silencing of endogenous MARCH8 in ESCC cells followed by LC-MS/MS analysis led to identification of 1029 unique proteins showing altered expression post MARCH8 knockdown. Several previously reported MARCH8 target proteins viz. TFR1, syntaxin-4, e-cadherin and CD44 were found to be upregulated. Furthermore, new putative targets of MARCH8, including β2M, were identified in the present study. We demonstrated that MARCH8 interacts with and ubiquitinates CDH1 and β2M. Inhibiting proteasome activity with MG132 prevented CDH1 and β2M degradation, indicating that MARCH8 might be targeting CDH1 and β2M for proteasomal degradation. Further, loss of β2M and CDH1 expression significantly and inversely correlated with MARCH8 expression in ESCC tissues (r = -0.737 and - 0.651, respectively; p < 0.01). In conclusion, our present study has led to identification of new targets of MARCH8 and suggests the role of MARCH8 in regulating CDH1 and β2M turnover in esophageal cancer cells. SIGNIFICANCE: The use of quantitative proteomics carried out has led to the recognition of new targets of MARCH8. The present study gives a broad understanding of the molecular remodeling arising in the ESCC after MARCH8 knockdown. The study also solidifies the idea that role of MARCH8 is not just limited to immunomodulation as silencing of MARCH8 affects various other processes such as protein processing and localization. This study might help in understanding the regulation of MARCH8 in ESCCs and the mechanism by which MARCH8 might be facilitating cancer cells to evade immune surveillance.
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