Purification of hepatitis C virus core protein in non-denaturing condition.

Hepatitis C virus (HCV) is the major cause of chronic hepatitis and hepatocellular carcinoma. Among its structural proteins, the HCV core protein has been implicated in liver disease. Understanding the role of HCV core proteins in viral diseases is crucial to elucidating disease mechanisms and identifying potential drug targets. However, purification challenges hinder the comprehensive elucidation of the structure and biochemical properties of HCV core proteins. In this study, we successfully solubilized bacterially expressed core protein using a high-salt and detergent-containing buffer and bypassed the denaturing-refolding process. Size-exclusion chromatography revealed three distinct peaks in the HCV-infected cell lysate, with the bacterially expressed soluble core protein corresponding to its second peak. Using a combination of affinity, size exclusion, and multi-modal chromatography purification techniques, we achieved a purity of > 95% for the core protein. Analytical ultracentrifugation revealed monomer formation in the solution. Far UV Circular dichroism spectroscopy identified 25.53% alpha helices and 20.26% beta sheets. These findings strongly suggest that the purified core proteins retained one of the native structures observed in HCV-infected cells.

Clinicopathological Features of Buccal Squamous Cell Carcinoma with Focus on Patients Who Never Smoke and Never Drink

Abstract Introduction Oral carcinoma has been reported at a substantial proportion in patients who never smoke and never drink. However, the proportion may vary by subsite and ethnicity. Objective We aimed to determine the clinicopathological features of buccal squamous cell carcinoma (SCC) in a Japanese population. Methods We retrospectively analyzed the records of patients diagnosed with buccal SCC at our institution from September 2002 to November 2015. We reviewed the gender, age, tumor status, treatment, smoking, alcohol drinking, multiple primary cancers, and prognosis of the patients. The overall and cause-specific survival rates were calculated, and the effects of clinicopathological variables were assessed by univariate analysis. Furthermore, the cause of death was evaluated. Results Among the 63 patients (men: 38; women: 25) included in the present study, 29 (46.0%) never smoked or drank. Women were almost 5 years older than men (p = 0.014). The number of women in the group who never smoked or drank was disproportionately higher than that of those in the smoker or drinker groups (p < 0.001). In total, 29 patients (46.0%) had 59 multiple primary cancers, including 26 oral cancers. Surgeries and radiotherapy were performed in 57 (90.5%) and 6 (9.5%) cases, respectively. The 5-year overall survival and disease-specific survival rates were 74.6 and 78.8%, respectively. Conclusion Our study confirms that buccal SCC may develop in older adult Japanese patients, especially in women who have never smoked or drank. These patients could be at risk for second primary malignancy.