Numerous studies propose that epigallocatechin-3-gallate (EGCG), an abundant polyphenol in green tea, has anti-cancer properties. However, its mechanism of action in breast cancer remains unclear. This study investigated the capacity of EGCG to suppress breast cancer cell growth in vitro and in vivo, characterizing the underlying mechanisms, focusing on the effect of EGCG on glucose metabolism. EGCG reduced breast cancer 4T1 cell growth in a concentration- (10–320 μM) and time- (12–48 h) dependent manner. EGCG induced breast cancer apoptotic cell death at 24 h, as evidenced by annexin V/PI, caspase 3, caspase 8 and caspase 9 activation. Furthermore, EGCG affected the expression of 16 apoptosis-related genes, and promoted mitochondrial depolarization. EGCG induced autophagy concentration-dependently in 4T1 cells by modulating the levels of the autophagy-related proteins Beclin1, ATG5 and LC3B. Moreover, EGCG affected glucose, lactate and ATP levels. Mechanistically, EGCG significantly inhibited the activities and mRNA levels of the glycolytic enzymes hexokinase (HK), phosphofructokinase (PFK), and lactic dehydrogenase (LDH), and to a lesser extent the activity of pyruvate kinase (PK). In addition, EGCG decreased the expression of hypoxia-inducible factor 1α (HIF1α) and glucose transporter 1 (GLUT1), critical players in regulating glycolysis. In vivo, EGCG reduced breast tumor weight in a dose-dependent manner, reduced glucose and lactic acid levels and reduced the expression of the vascular endothelial growth factor (VEGF). In conclusion, EGCG exerts an anti-tumor effect through the inhibition of key enzymes that participate in the glycolytic pathway and the suppression of glucose metabolism.
Background: Early detection and treatment of bacterial sexually transmitted infections has been advocated as an HIV prevention strategy. Aim: To inform screening guidelines, the incidence and risk factors for urethral and anal gonorrhoea and chlamydia were studied in a prospective cohort of community-based HIV negative homosexual men in Sydney, New South Wales, Australia. Methods: All participants were offered annual screening for gonorrhoea and chlamydia (study-visit diagnoses) on urine and anal swabs using nucleic acid amplification. Participants also reported diagnoses of gonorrhoea and chlamydia made elsewhere between interviews (interval diagnoses). All diagnoses were summed to create a combined incidence rate, and detailed data on specific sexual practices with casual and regular partners were collected. Results: Among 1427 men enrolled, the combined incidence rates were 3.49 and 2.96 per 100 person-years for urethral and anal gonorrhoea, respectively; and 7.43 and 4.98 per 100 person-years for urethral and anal chlamydia, respectively. Urethral infections were associated with unprotected anal intercourse (UAI) with HIV-positive partners (hazard ratio (HR) = 2.58, 95% CI 1.10 to 6.05 for urethral gonorrhoea) and with frequent insertive oral sex (p for trend 0.007 for urethral chlamydia). Anal infections were associated with receptive UAI (p for trend 0.001 for both anal gonorrhoea and chlamydia) and other receptive anal sexual practices. Stratified analyses showed the independence of the associations of insertive oral sex with urethral infections and of non-intercourse receptive anal practices with anal infections. Conclusion: Incident gonorrhoea and chlamydia were common. Risk behaviours for both urethral and anal infections were not restricted to UAI. Screening that includes tests for anal and urethral infections should be considered for all sexually active homosexual men, not just for those who report UAI.
Analysis of cancer risk in primary immune deficiency (PID) offers insight into the relationship between immune function and cancer. Data on Australian patients (n = 1132) notified voluntarily to the Australasian Society of Clinical Immunology and Allergy PID Registry (1990-2008) were linked with national death and cancer registries. Person-years of follow-up commenced from up to 15 years before registration on the PID Registry or January 1982, the inception of national cancer registration. Site-specific, 5-year age-, sex-, calendar year–, and state-standardized incidence ratios (SIRs) with 95% confidence intervals (95% CIs) were calculated for all cancers except nonmelanocytic skin cancer. During an average of 16 person-years follow-up, a 1.6-fold excess relative risk of cancer was observed (n = 58; SIR 1.60, 95% CI 1.22-2.07) for all PID combined. Relative risk was increased for non-Hodgkin lymphoma (n = 16; SIR 8.82, 95% CI 5.04-14.30), leukemia (n = 4; SIR 5.36, 95% CI 1.46-13.73), and stomach cancer (n = 3; SIR 6.10, 95% CI 1.26-17.84). Excess cancer risk was observed for predominantly antibody deficiencies and other well-defined immunodeficiency syndromes. Results suggest that predominantly antibody deficiencies may be associated with a narrower range of solid cancers than immunodeficiency characterized by predominantly T-cell deficiency, such as iatrogenic and HIV-related immunodeficiency, although this requires confirmation in larger cohorts.