Methylated SDC2 testing in stool DNA for early screening of colorectal cancer in Shipai Town, Dongguan City / 中华胃肠外科杂志

Objective: To explore the utility of stool-based DNA test of methylated SDC2 (mSDC2) for colorectal cancer (CRC) screening in residents of Shipai Town, Dongguan City. Methods: This was a cross-sectional study. Using a cluster sampling method, residents of 18 villages in Shipai Town, Dongguan City were screened for CRC from May 2021 to February 2022. In this study, mSDC2 testing was employed as a preliminary screening method. Colonoscopy examination was recommended for individuals identified as high-risk based on the positive mSDC2 tests. The final screening results, including the rate of positive mSDC2 tests, the rate of colonoscopy compliance, the rate of lesions detection, and the cost-effectiveness of screening, were analyzed to explore the benefits of this screening strategy. Results: A total of 10 708 residents were enrolled and completed mSDC2 testing, giving a participation rate of 54.99% (10 708/19 474) and a pass rate of 97.87% (10 708/10 941). These individuals included 4 713 men (44.01%) and 5 995 women (55.99%) with a mean age of (54.52±9.64) years. The participants were allocated to four age groups (40-49, 50-59, 60-69, and 70-74 years), comprising 35.21%(3770/10 708), 36.25% (3882/10 708), 18.84% (2017/10 708), and 9.70% (1039/10 708) of all participants, respectively. mSDC2 testing was positive in 821/10 708 (7.67%) participants, 521 of whom underwent colonoscopy, resulting in a compliance rate of 63.46% (521/821). After eliminating of 8 individuals without pathology results, data from 513 individuals were finally analyzed. Colonoscopy detection rate differed significantly between age groups (χ2=23.155, P<0.001),ranging from a low of 60.74% in the 40-49 year age group to a high of 86.11% in the 70-74 year age group. Colonoscopies resulted in the diagnosis of 25 (4.87%) CRCs, 192 (37.43%) advanced adenomas, 67 (13.06%) early adenomas, 15 (2.92%) serrated polyps, and 86 (16.76%) non- adenomatous polyps. The 25 CRCs were Stage 0 in 14 (56.0%) individuals, stage I in 4 (16.0%), and Stage II in 7(28.0%). Thus, 18 of the detected CRCs were at an early stage. The early detection rate of CRCs and advanced adenomas was 96.77% (210/217). The rate of mSDC2 testing for all intestinal lesions was 75.05% (385/513). In particular, the financial benefit of this screening was 32.64 million yuan, and the benefit-cost ratio was 6.0. Conclusion: Screening for CRCs using stool-based mSDC2 testing combined with colonoscopy has a high lesion detection rate and a high cost-effectiveness ratio. This is a CRC screening strategy that deserves to be promoted in China.

Human normal biliary epithelial cells transformation and tumor development induced by hepatitis C virus core protein / 中华外科杂志

<p><b>OBJECTIVE</b>To study the effect of hepatitis C virus core protein (HCV-C) on human normal biliary epithelial cells (BEC) transformation and tumor development.</p><p><b>METHODS</b>BEC cells were transfected with plasmid pcDNA HCV-C (expressing HCV-C) by lipofectamine and selected in G418. The expression of HCV-C gene and protein was determined by PCR and immunohistochemical staining, respectively. Biological effect of transfected cells was observed through cell proliferation assay, anchor independent growth, and tumor development in nude mice. The expression of HCV-C protein in the induced tumor was evaluated by immunohistochemistry.</p><p><b>RESULTS</b>HCV-C was strongly expressed in BEC cells transfected with plasmid pcDNA HCV-C and the positive signal was located in cytoplasm. The HCV-C expression protein in the induced cytoplasm. Cell proliferation assay showed that the population doubling time in the pcDNA HCV-C transfected cells was much shorter than that in the pcDNA3 and non-transfected cells (14 h, 28 h, 30 h respectively). The cloning efficiencies of transfected cells with pcDNA HCV-C, pcDNA3 and non-transfected cells were 36%, 2.5% and 1.5%, respectively (P < 0.01). Tumor developed in nude mice inoculated with pcDNA HCV-C transfected cells after the inoculation. HE staining showed bile duct carcinoma character and immunohistochemistry confirmed HCV-C expression in the tumor tissue. The positive control group also showed tumor development, while no tumor mass obtained in the nude mice inoculated with pcDNA3 and non-transfected cells even 36 days after the injection.</p><p><b>CONCLUSION</b>HCV-C protein showed human normal biliary epithelial cells transformation and tumorigenic features.</p>