Telomere length variation and expression analysis of shelterin complex genes during gallbladder carcinogenesis.

BACKGROUND: Telomeres, which are bound with shelterin protein complex, play an important role in maintaining genomic stability and its dysfunction may lead to carcinogenesis. Here, we aimed to analyze whether shelterin complex gene expression and telomere length variation, play any role in gallbladder carcinogenesis. METHODS: Telomere length analysis was carried out by monochrome multiplex qPCR, whereas expression analysis of shelterin genes was carried out using RT-qPCR. Statistical analysis was carried out using SigmaPlot 11 software. RESULTS: We found significantly reduced telomere length in tumor tissues, and this reduction was seen in both, tumors with or without gallstones in comparison to adjacent non tumor and gallstone (chronic calculous cholecystitis: Inflamed) tissues. Inflamed tissues showed increased telomere length as compared to both adjacent non tumor and tumor tissues. Expression analysis of five shelterin genes showed significant downregulation of TERF1, POT1, and TINF2 genes in inflamed tissues as compared to non tumor and tumor tissues. POT1 was also found to be significantly upregulated in tumor tissues and specifically in tumor tissues with gallstones compared to inflamed tissues. CONCLUSION: This study, thus, suggests that, gallstone does not affect telomere length and even after having increased telomere length, decreased expression of some shelterin genes in inflamed tissue might cause telomeres to cap improperly, possibly leading to telomere dysfunction and further, gallbladder carcinogenesis. Also, increased expression of POT1 in tumor tissues with gallstones could act as a diagnostic marker in patients with gallstones.

Epigenetic profiling of gallbladder cancer and gall stone diseases: Evaluation of role of tumour associated genes.

BACKGROUND: As on today, the global mortality rate of gallbladder cancer is still very high. Both genetic and epigenetic alterations play pivotal roles in the development of cancer. We selected seven tumour associated genes, implicated in other cancers, to assess their methylation status in gallbladder cancer and gallstone diseases. AIM OF STUDY: To study the promoter methylation of certain tumour associated genes in the molecular pathogenesis of gallbladder cancer and gall stone diseases. MATERIALS AND METHODS: Methylation specific PCR for seven tumour associated genes, viz., MASPIN, 14-3-3 sigma gene, THBS1, FLNC, HLTF, COX-2 and SOCS1, was performed in 50 gallbladder cancer (GBC), 30 gall stone diseases (GSD) and their respective adjacent control tissues. Semi-quantitative PCR and immunohistochemistry was carried out to check the expression level. Student's t-test was carried out to compare the differences in the methylation and expression patterns between cases and control tissues. RESULTS: We observed methylation of CpG islands in seven of the studied markers, but, the frequency of methylation was found varying among different samples. Of them, 14-33 sigma showed methylation in 45 GBC (90%; p=0.0001) and 25 GSD (86.66%; p=0.001), MASPIN in 35 GBC (70%; p=0.0008) and 18 GSD (51.43%; p=0.040), FLNC in 16 GBC (32%; p=0.0044) and 9 GSD (25.71%; p=ns), THBS1 in 26 GBC (52%; p=0.0009) and 10 GSD (28.57%; p=0.0505), HLTF in 8 GBC (16%; p=ns) and 2 GSD (5.71%; p=ns), COX2 in 10 GBC (20%; p=ns) and 6 GSD (17.14%; p=ns) and SOCS-1 in 3 GBC samples only (6%; p=ns), but not in GSD. Semi-quantitative PCR revealed down regulation in MASPIN, 14-3-3 sigma, THBS1, HLTF, COX2 and SOCS1 in advanced gallbladder cases. Immunohistochemistry further confirmed the down-regulation of SOCS1 in GBC. CONCLUSION: The present study infers that accumulation of epigenetic alterations increases poor prognosis of GBC patients. Out of seven genes, MASPIN and THBS1 play key epigenetic role in GBC, but not in GSD. The reason for downregulation of SOCS1 only in GBC, and unaltered expression of 14-3-3 sigma protein in all the GBC and GSD tissue samples is not clear. Further investigation on the expression pattern of these genes in GBC cell lines may elucidate their likely functional role in in association with gallbladder cancer.

Analysis of autosomal dominant spinocerebellar ataxia type 1 in an extended family of central India.

BACKGROUND: Spinocerebeller ataxia type 1 (SCA1) is a specific type of ataxia among a group of inherited diseases of the central nervous system. In SCA1, genetic defects lead to impairment of specific nerve fibers carrying messages to and from the brain, resulting in the degeneration of the cerebellum, the coordination center of the brain. We investigated 24 members of an extended family in Gwalior city, India, some of which were earlier clinically diagnosed to be suffering from yet unconfirmed type of SCA neurodegenerative disorder. MATERIALS AND METHODS: All the family members from each age group were screened clinically and the characteristics of those resembling with ataxia were recorded for diagnosis by MRI. The confirmed patients of the family were genetically tested by PCR based molecular testing to identify the type of SCA (i.e., SCA 1, 2, 3, 4, 6 or 7). Family tree of the disease inheritance was constructed by pedigree based method. RESULT AND CONCLUSION: We found the clinical (symptoms and MRI) and genetic (Pedigree and PCR) results to be correlated. The PCR result revealed the disease to be of SCA 1 type being inherited in the family.

Quantitative Assessment of Expression of Lactate Dehydrogenase and its Isoforms 3 and 4 may Serve as Useful Indicators of Progression of Gallbladder Cancer: A Pilot Study.

We have studied the expression of lactate dehydrogenase and its isoforms in gall bladder cancer, cholelithiasis and chronic cholecystitis. Quantitative and qualitative assays of lactate dehydrogenase and its various isoforms were carried out in the blood sera of patients and healthy controls along with parallel estimation of various liver function test enzymes. Statistical analysis was done using the software Graph Pad Prism. Significantly high expression of lactate dehydrogenase along with alkaline phosphatase and total bilirubin (P ≤ 0.05) was observed in all the three clinical conditions as compared to controls. LDH showed an increasing trend from stage I to stage IV of GBC indicating a significant positive association with the disease progression. The levels of LDH 3 and 4 isoforms appeared significantly more elevated in GBC than cholelithiasis or chronic cholecystitis. We suggest that a careful estimation of total LDH and its isoforms 3 and 4 alone or along with alkaline phosphatase and total bilirubin during different clinical stages, like chronic cholecystitis, cholelithiasis and GBC, may prove to be a potentially useful biomarker in the prognostic management of gall bladder diseases, specifically GBC.