Streptococcus gallolyticus subsp. gallolyticus (Sg) has long been known to have a strong association with colorectal cancer (CRC). This knowledge has important clinical implications, and yet little is known about the role of Sg in the development of CRC. Here we demonstrate that Sg promotes human colon cancer cell proliferation in a manner that depends on cell context, bacterial growth phase and direct contact between bacteria and colon cancer cells. In addition, we observed increased level of β-catenin, c-Myc and PCNA in colon cancer cells following incubation with Sg. Knockdown or inhibition of β-catenin abolished the effect of Sg. Furthermore, mice administered with Sg had significantly more tumors, higher tumor burden and dysplasia grade, and increased cell proliferation and β-catenin staining in colonic crypts compared to mice receiving control bacteria. Finally, we showed that Sg is present in the majority of CRC patients and is preferentially associated with tumor compared to normal tissues obtained from CRC patients. These results taken together establish for the first time a tumor-promoting role of Sg that involves specific bacterial and host factors and have important clinical implications. Colorectal cancer (CRC) is a leading cause of cancer-related death. The recognition that microbial agents can contribute to the development of CRC raises hope for improving CRC diagnosis and treatment by incorporating both microbial and patient characteristics into clinical strategies. S. gallolyticus subsp. gallolyticus (Sg) has been implicated in CRC for decades. Patients with Sg infections display a much higher risk of having CRC compared to the general population. Despite this, the precise role of Sg in the development of CRC—i.e., whether this organism plays an active role in the development of tumor or its presence is merely a consequence of the tumor environment being favorable for its colonization of the colon—was unknown. Here using in vitro cell cultures and mouse models of CRC, we demonstrate that Sg actively promotes colon cancer cell proliferation and tumor growth, suggesting that it is not an innocent “passenger”. These results represent a major step forward in understanding the relationship between Sg and CRC. This combined with the prevalence of Sg in CRC patients highlight Sg as being both clinically relevant and functionally important for CRC.

After more than a century, aspirin remains one of the most commonly used drugs in western medicine. Although mainly used for its anti-thrombotic, anti-pyretic, and analgesic properties, a multitude of clinical studies have provided convincing evidence that regular, low-dose aspirin use dramatically lowers the risk of cancer. These observations coincide with recent studies showing a functional relationship between platelets and tumors, suggesting that aspirin’s chemopreventive properties may result, in part, from direct modulation of platelet biology and biochemistry. Here, we present a review of the biochemistry and pharmacology of aspirin with particular emphasis on its cyclooxygenase-dependent and cyclooxygenase-independent effects in platelets. We also correlate the results of proteomic-based studies of aspirin acetylation in eukaryotic cells with recent developments in platelet proteomics to identify non-cyclooxygenase targets of aspirin-mediated acetylation in platelets that may play a role in its chemopreventive mechanism.

Objective Aspirin and non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs) are preventive against cardiovascular disease (CVD) and several cancer types, but long-term use has been associated with significant health risks, resulting in conflicting recommendations on NSAID use for prevention of CVD and cancer. Previous research indicates that aspirin use increases with age and CVD risk factors and that a large percentage of the US population regularly use analgesics, including NSAIDs, but there has not been a recent, in-depth assessment of NSAID use prevalence, changes in use over time or predictors of NSAID use in the USA. Methods We used the cross-sectional, National Health And Nutrition Examination Survey (NHANES) from 1988 to 1994 and three continuous cycles (1999–2004) to assess regular NSAID use prevalence, changes over time and predictors of regular NSAID use. Results Overall, regular NSAID use increased over time and varied by demographic features. Participants over 60 years of age, women, participants with high body mass index, increased waist circumference or heart disease were significantly more likely to be regular NSAID users. By contrast, non-Hispanic African American and Mexican American participants were significantly less likely to regularly use NSAIDs. Conclusions This study uses a nationally representative data set (NHANES) to provide an exploration of regular NSAID use patterns over time, highlighting several demographic, lifestyle and clinical conditions associated with regular NSAID use. Understanding who is likely to regularly use NSAIDs enables more targeted messaging both for increasing the preventive benefits and for limiting the toxicities associated with regular use of NSAIDs.

Androgen-withdrawal-induced apoptosis (AWIA) is deregulated in androgen refractory prostate cancer. Androgens have been shown to positively regulate expression of the antiapoptotic FADD-like interleukin-1β-converting enzyme (FLICE)-like inhibitory protein (FLIP), and reduced FLIP expression precedes apoptosis after androgen withdrawal. Here, we show that FLIP protein expression is downregulated in castrated rats, while in LNCaP cells, androgens regulate FLIP in a manner that is dependent on phosphoinositol-3-kinase (PI3K) and Akt signaling. Specifically, treatment of LNCaP cells with LY294002, or expression of either PTEN or a non-phosphorylatable form of FOXO3a (FOXO3aTM), downregulates FLIP protein and mRNA. Conversely, treatment with androgens in the absence of PI3/Akt signaling, or following expression of FOXO3aTM, leads to increased FLIP expression. A FOXO3a binding site was identified in the FLIP promoter and shown necessary for the combined effects of androgens and FOXO3a on FLIP transcription. FOXO3a binds the androgen receptor, suggesting that the transcriptional synergy depends on an interaction between these proteins. Finally, LNCaP cells are sensitized to TRAIL-induced apoptosis by PTEN or LY294002, and rescued by androgens. FOXO3aTM also sensitizes cells to androgen-inhibited TRAIL apoptosis. Androgen rescue was diminished when either FOXO3a or FLIP was reduced by siRNA. These data support a role for FOXO3a in AWIA.