Changes in serum hepatitis B e antigen (HBeAg) levels associated with the emergence of YMDD mutants in HBeAg non-seroconverted patients during lamivudine therapy.

Background: To elucidate the associations between the changing patterns of hepatitis B e antigen (HBeAg) levels and the emergence of tyrosine–methionine–aspartate–aspartate (YMDD) mutants in HBeAg non‐seroconverted patients undergoing lamivudine therapy. Methods: This study analysed 76 HBeAg‐positive naïve chronic hepatitis B patients treated with lamivudine. The median duration of therapy was 52 weeks. The YMDD mutants were detected in 35 patients. The changing patterns of HBeAg levels were categorized into three groups: Descending, Descending–Ascending and Fluctuation. HBeAg breakthrough was defined as progressive HBeAg decreasing to <10% of pretreatment levels, followed by increases exceeding 50 S/Co [the ratio of the sample (S) to the cut‐off (Co)] above nadir levels. Results: Of 76 patients, the sensitivity and specificity for predicting YMDD mutants by the Descending–Ascending pattern were 66 and 100% respectively. Of 17 patients with YMDD mutants in the Descending–Ascending group, hepatitis B virus (HBV) DNA first increased, followed by increased HBeAg levels and finally by biochemical breakthrough. The median intervals between virological breakthrough and HBeAg breakthrough, between HBeAg breakthrough and biochemical breakthrough and between virological breakthrough and biochemical breakthrough were 4, 24 and 33 weeks respectively. Conclusions: Serial HBeAg levels are useful in predicting YMDD mutant emergence in HBeAg non‐seroconverted patients during lamivudine therapy.     

S100P interacts with integrin α7 and increases cancer cell migration and invasion in lung cancer

S100P, a Ca2⁺ binding protein, has been shown to be overexpressed in various cancers. However, its functional character in lung cancer remains largely unknown. In this study, we show that S100P increases cancer migration, invasion and metastasis in lung cancer cells. Ectopic expression of S100P increases migration, invasion and EMT in less invasive CL1-0 lung cancer cells. Conversely, knockdown of S100P suppressed migration and invasion, and caused a reversion of EMT in highly invasive lung cancer cells. These effects were transduced by increasing the interaction of S100P with integrin α7, which activated focal adhesion kinase (FAK) and AKT. Blocking FAK significantly decreased S100P-induced migration by decreasing Src and AKT activation, whereas inhibiting AKT reduced S100P upregulation on ZEB1 expression. Further study has indicated that S100P knockdown prevents the spread of highly metastatic human lung cancer in animal models. This study therefore suggests that S100P represents a critical activator of lung cancer metastasis. Detection and targeted treatment of S100P-expressing cancer is an attractive therapeutic strategy in treating lung cancer.     

Involvement of reactive oxygen species/c-Jun NH(2)-terminal kinase pathway in kotomolide A induces apoptosis in human breast cancer cells

The anticancer effects of kotomolide A (KTA), a new butanolide constituent isolated from the leaves of Cinnamomum kotoense (Lauraceae), on the two human breast cancer cell lines MCF-7 and MDA-MB-231, were first investigated in our study. KTA exhibited selectively antiproliferative effects in cancer cell lines without showing any toxicity in normal mammary epithelial cells. Treatment of cancer cells with KTA to trigger G2/M phase arrest was associated with increased p21/WAF1 levels and reduced amounts of cyclin A, cyclin B1, cdc2 and cdc25C. KTA induced cancer cell death treatment by triggering mitochondrial and death receptor 5 (DR5) apoptotic pathways, but did not act on the Fas receptor. Exposure of MCF-7 and MDA-MB-231 cells to KTA resulted in cellular glutathione reduction and ROS generation, accompanied by JNK activation and apoptosis. Both antioxidants, NAC and catalase, significantly decreased apoptosis by inhibiting the phosphorylation of JNK and subsequently triggering DR5 cell death pathways. The reduction of JNK expression by siRNA decreased KTA-mediated Bim cleavage, DR5 upregulation and apoptosis. Furthermore, daily KTA i.p. injections in nude mice with MDA-MB-231 s.c. tumors resulted in a 50% decrease of mean tumor volume, compared with vehicle-treated controls. Taken together, the data show that cell death of breast cancer cells in response to KTA is dependent upon ROS generation and JNK activation, triggering intrinsic and extrinsic apoptotic pathways. The ROS/JNK pathway could be a useful target for novel approaches in breast cancer chemotherapy.     

Possible mechanisms mediating apoptosis of bronchial epithelial cells in chronic obstructive pulmonary disease – A next-generation sequencing approach

Purpose

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory airway disease characterized by persistent airflow limitation. Apoptosis of pulmonary structural cells contributes to pulmonary destruction and dysfunction. This study aimed to explore the possible mechanisms underlying decreased cell proliferation and increased apoptosis of bronchial epithelial cells of COPD.