Male circumcision and prostate cancer: a meta-analysis revisited.

INTRODUCTION The relationship between circumcision and prostate cancer has been controversial. A recently published meta-analysis contradicted previous meta-analyses of male circumcision and prostate cancer risk. Our aim was to conduct a de novo meta-analysis and critically evaluate this recent paper published by Van Howe. MATERIALS AND METHODS: We retrieved data from each of the 12 source studies Van Howe used, then performed a random effects meta-analysis of those data. We critically examined the data and other information in Van Howe's study. RESULTS: Using the same values as Van Howe, we confirmed his finding of a positive association of circumcision with prostate cancer (random effects summary OR = 1.14; 95% CI 0.99, 1.31). However, our independent meta-analysis found a negative association of circumcision with prostate cancer (random effects summary OR= 0.87; 95% CI 0.76, 1.00; p = 0.05). The reason for this critical discrepancy was Van Howe's erroneous transposition of values for circumcised and uncircumcised men in his Table columns, leading to inversion of the result. We further critically evaluated a geographical analysis and cost analysis of circumcision and prostate cancer, as well as claims denying a role for sexually transmitted infections in prostate cancer etiology, finding these too to be misleading. CONCLUSIONS: Van Howe's 2020 meta-analysis was based on erroneous data transposition leading to an inverted outcome. The journal concerned recently corrected his Table. Van Howe's claim of a positive association of circumcision with country-level-age standardized prostate cancer prevalence and his cost analysis were found to be questionable. Our meta-analysis showed that circumcision is associated with lower prostate cancer risk.

Dual targeting of EZH2 and androgen receptor as a novel therapy for castration-resistant prostate cancer.

Castration-resistant prostate cancer (CRPC) emerges after androgen withdrawal therapy and remains incurable due to the lack of effective treatment protocols. Treatment with enzalutamide, a second generation androgen receptor (AR) antagonist, offers an initial response followed by drug resistance and tumor relapse. Enhancer of zeste homolog 2 (EZH2), a member of PRC2 complex, is an important target that acts as a coactivator of AR-mediated gene suppression whose oncogenic activity increases during castration. We hypothesize that dual targeting of EZH2 and AR could be highly effective in CRPC treatment. The present study aimed to examine the effectiveness of combination using EZH2 inhibitor GSK126 with antiandrogen enzalutamide in the treatment of CRPC cells. Treatment of 22Rv1 and C42B CRPC cells with a combination of GSK126 and enzalutamide led to synergistic inhibition of cell proliferation, cell cycle arrest and marked increase in cell death. Mechanistically, this combination treatment significantly reduced expression of AR and AR-v7, decrease in PSA and Akt activity, diminution of EZH2 and other members of PCR2 complex including SUZ12 and EED, with simultaneous loss of H3K27 trimethylation and dissociation between AR and PRC2 complex members compared to individual treatment. This study provides preclinical proof-of-concept that combined treatment of EZH2 inhibitor with AR antagonist results in synergistic anticancer effects opening new possibilities for treatment of CRPC tumors.

Comments by opponents on the British Medical Association's guidance on non-therapeutic male circumcision of children seem one-sided and may undermine public health.

The British Medical Association (BMA) guidance on non-therapeutic circumcision (NTMC) of male children is limited to ethical, legal and religious issues. Here we evaluate criticisms of the BMA's guidance by Lempert et al. While their arguments promoting autonomy and consent might be superficially appealing, their claim of high procedural risks and negligible benefits seem one-sided and contrast with high quality evidence of low risk and lifelong benefits. Extensive literature reviews by the American Academy of Pediatrics and the United States Centers for Disease Control and Prevention in developing evidence-based policies, as well as risk-benefit analyses, have found that the medical benefits of infant NTMC greatly exceed the risks, and there is no reduction in sexual function and pleasure. The BMA's failure to consider the medical benefits of early childhood NTMC may partly explain why this prophylactic intervention is discouraged in the United Kingdom. The consequence is higher prevalence of preventable infections, adverse medical conditions, suffering and net costs to the UK's National Health Service for treatment of these. Many of the issues and contradictions in the BMA guidance identified by Lempert et al stem from the BMA's guidance not being sufficiently evidence-based. Indeed, that document called for a review by others of the medical issues surrounding NTMC. While societal factors apply, ultimately, NTMC can only be justified rationally on scientific, evidence-based grounds. Parents are entitled to an accurate presentation of the medical evidence so that they can make an informed decision. Their decision either for or against NTMC should then be respected.

Critical evaluation of contrasting evidence on whether male circumcision has adverse psychological effects: A systematic review.

OBJECTIVE: To conduct the first systematic review critically examining evidence on whether early male circumcision has short- and long-term adverse psychological effects. METHODS: We searched PubMed, EMBASE, SCOPUS, Cochrane Library, and Google Scholar. RESULTS: Twenty-four studies with original data met the inclusion criteria. These comprised 11,173 total males, 4340 circumcised in infancy and 6908 uncircumcised. Nineteen were rated 1+, 2++ or 2+, and 5 were rated 2- by SIGN criteria. Neonatal circumcision, particularly without anesthetic, increased vaccination pain response, but had little effect on breastfeeding or cognitive ability. Studies reporting associations with sudden infant death syndrome, autism, alexithymia and impaired sexual function and pleasure had design flaws and were rated 2-. Sexual arousal, touch, pain, and warmth thresholds measured by quantitative sensory testing were not diminished in neonatally circumcised men. Neonatal circumcision was not associated with empathy in men, contradicting the hypothesis that procedural pain causes central nervous system changes. After correcting all associations with socioaffective processing parameters for multiple testing only higher sociosexual desire, dyadic sexual libido/drive, and stress remained significant. The relatively greater sexual activity found in circumcised men might reflect reduced sexual activity in uncircumcised men overall owing to pain and psychological aversion in those with foreskin-related medical conditions (reverse causality). Most studies employed case-control designs with limited follow-up. Studies beyond childhood were prone to confounding. CONCLUSION: The highest quality evidence suggest that neonatal and later circumcision has limited or no short-term or long-term adverse psychological effects.

Thioredoxin reductase is a major regulator of metabolism in leukemia cells.

Despite the fact that AML is the most common acute leukemia in adults, patient outcomes are poor necessitating the development of novel therapies. We identified that inhibition of Thioredoxin Reductase (TrxR) is a promising strategy for AML and report a highly potent and specific inhibitor of TrxR, S-250. Both pharmacologic and genetic inhibition of TrxR impairs the growth of human AML in mouse models. We found that TrxR inhibition leads to a rapid and marked impairment of metabolism in leukemic cells subsequently leading to cell death. TrxR was found to be a major and direct regulator of metabolism in AML cells through impacts on both glycolysis and the TCA cycle. Studies revealed that TrxR directly regulates GAPDH leading to a disruption of glycolysis and an increase in flux through the pentose phosphate pathway (PPP). The combined inhibition of TrxR and the PPP led to enhanced leukemia growth inhibition. Overall, TrxR abrogation, particularly with S-250, was identified as a promising strategy to disrupt AML metabolism.

Critical evaluation of arguments opposing male circumcision: A systematic review.

OBJECTIVE: To systematically evaluate evidence against male circumcision (MC). METHODS: We searched PubMed, Google Scholar, EMBASE and Cochrane databases. RESULTS: Database searches retrieved 297 publications for inclusion. Bibliographies of these yielded 101 more. After evaluation we found: Claims that MC carries high risk were contradicted by low frequency of adverse events that were virtually all minor and easily treated with complete resolution. Claims that MC causes psychological harm were contradicted by studies finding no such harm. Claims that MC impairs sexual function and pleasure were contradicted by high-quality studies finding no adverse effect. Claims disputing the medical benefits of MC were contradicted by a large body of high-quality evidence indicating protection against a wide range of infections, dermatological conditions, and genital cancers in males and the female sexual partners of men. Risk-benefit analyses reported that benefits exceed risks by 100-200 to 1. To maximize benefits and minimize risks, the evidence supported early infant MC rather than arguments that the procedure should be delayed until males are old enough to decide for themselves. Claims that MC of minors is unethical were contradicted by balanced evaluations of ethical issues supporting the rights of children to be provided with low-risk, high-benefit interventions such as MC for better health. Expert evaluations of case-law supported the legality of MC of minors. Other data demonstrated that early infant MC is cost-saving to health systems. CONCLUSIONS: Arguments opposing MC are supported mostly by low-quality evidence and opinion, and are contradicted by strong scientific evidence.

Membrane bound IL-21 based NK cell feeder cells drive robust expansion and metabolic activation of NK cells.

NK cell adoptive therapy is a promising cancer therapeutic approach, but there are significant challenges that limiting its feasibility and clinical efficacy. One difficulty is the paucity of clinical grade manufacturing platforms to support the large scale expansion of highly active NK cells. We created an NK cell feeder cell line termed 'NKF' through overexpressing membrane bound IL-21 that is capable of inducing robust and sustained proliferation (>10,000-fold expansion at 5 weeks) of highly cytotoxic NK cells. The expanded NK cells exhibit increased cytotoxic function against a panel of blood cancer and solid tumor cells as compared to IL-2-activated non-expanded NK cells. The NKF-expanded NK cells also demonstrate efficacy in mouse models of human sarcoma and T cell leukemia. Mechanistic studies revealed that membrane-bound IL-21 leads to an activation of a STAT3/c-Myc pathway and increased NK cell metabolism with a shift towards aerobic glycolysis. The NKF feeder cell line is a promising new platform that enables the large scale proliferation of highly active NK cells in support of large scale third party NK cell clinical studies that have been recently intiatied. These results also provide mechanistic insights into how membrane-bound IL-21 regulates NK cell expansion.

Inhibiting TGF-beta signaling preserves the function of highly activated, in vitro expanded natural killer cells in AML and colon cancer models.

Natural killer cells harnessed from healthy individuals can be expanded ex vivo using various platforms to produce large doses for adoptive transfer into cancer patients. During such expansion, NK cells are increasingly activated and more efficient at killing cancer cells. Adoptive transfer however introduces these activated cells into a highly immunosuppressive tumor microenvironment mediated in part by excessive transforming growth factor beta (TGF-beta) from both cancer cells and their surrounding stroma. This microenvironment ultimately limits the clinical efficacy of NK cell therapy. In this study, we examined the use of a TGF-beta receptor kinase inhibitor, LY2157299, in preserving the cytotoxic function of ex vivo expanded, highly activated NK cells following sustained exposure to pathologic levels of TGF-beta in vitro and in a liver metastases model of colon cancer. Using myeloid leukemia and colon cancer cell lines, we show that the TGF-beta driven impairment of NK cell cytotoxicity is mitigated by LY2157299. We demonstrate this effect using quantitative cytotoxicity assays as well as by showing a preserved activated phenotype with high NKG2D/CD16 expression and enhanced cytokine production. In a mouse liver metastases model of colon cancer, we observed significantly improved eradication of liver metastases in mice treated with adoptive NK cells combined with LY2157299 compared with mice receiving NK cells or TGF beta inhibition alone. We propose that the therapeutic efficacy of adoptive NK cell therapy clinically will be markedly enhanced by complementary approaches targeting TGF-beta signaling in vivo.

Correction: Inhibiting TGF-beta signaling preserves the function of highly activated, in vitro expanded natural killer cells in AML and colon cancer models.

[This corrects the article DOI: 10.1371/journal.pone.0191358.].

GSK-3 Inhibition Sensitizes Acute Myeloid Leukemia Cells to 1,25D-Mediated Differentiation.

1,25-dihydroxyvitamin D3 (1,25D), the biologically active form of vitamin D, is widely considered a promising therapy for acute myeloid leukemia (AML) based on its ability to drive differentiation of leukemic cells. However, clinical trials have been disappointing in part to dose-limiting hypercalcemia. Here we show how inhibiting glycogen synthase kinase 3 (GSK3) can improve the differentiation response of AML cells to 1,25D-mediated differentiation. GSK3 inhibition in AML cells enhanced the differentiating effects of low concentrations of 1,25D. In addition, GSK3 inhibition augmented the ability of 1,25D to induce irreversible growth inhibition and slow the progression of AML in mouse models. Mechanistic studies revealed that GSK3 inhibition led to the hyperphosphorylation of the vitamin D receptor (VDR), enabling an interaction between VDR and the coactivator, SRC-3 (NCOA3), thereby increasing transcriptional activity. We also found that activation of JNK-mediated pathways in response to GSK3 inhibition contributed to the potentiation of 1,25D-induced differentiation. Taken together, our findings offer a preclinical rationale to explore the repositioning of GSK3 inhibitors to enhance differentiation-based therapy for AML treatment. Cancer Res; 76(9); 2743-53. ©2016 AACR.

Repression of GSK3 restores NK cell cytotoxicity in AML patients.

Natural killer cells from acute myeloid leukaemia patients (AML-NK) show a dramatic impairment in cytotoxic activity. The exact reasons for this dysfunction are not fully understood. Here we show that the glycogen synthase kinase beta (GSK3ß) expression is elevated in AML-NK cells. Interestingly, GSK3 overexpression in normal NK cells impairs their ability to kill AML cells, while genetic or pharmacological GSK3 inactivation enhances their cytotoxic activity. Mechanistic studies reveal that the increased cytotoxic activity correlates with an increase in AML-NK cell conjugates. GSK3 inhibition promotes the conjugate formation by upregulating LFA expression on NK cells and by inducing ICAM-1 expression on AML cells. The latter is mediated by increased NF-κB activation in response to TNF-α production by NK cells. Finally, GSK3-inhibited NK cells show significant efficacy in human AML mouse models. Overall, our work provides mechanistic insights into the AML-NK dysfunction and a potential NK cell therapy strategy.

A Novel Glycogen Synthase Kinase-3 Inhibitor Optimized for Acute Myeloid Leukemia Differentiation Activity.

Standard therapies used for the treatment of acute myeloid leukemia (AML) are cytotoxic agents that target rapidly proliferating cells. Unfortunately, this therapeutic approach has limited efficacy and significant toxicity and the majority of AML patients still die of their disease. In contrast to the poor prognosis of most AML patients, most individuals with a rare subtype of AML, acute promyelocytic leukemia, can be cured by differentiation therapy using regimens containing all-trans retinoic acid. GSK3 has been previously identified as a therapeutic target in AML where its inhibition can lead to the differentiation and growth arrest of leukemic cells. Unfortunately, existing GSK3 inhibitors lead to suboptimal differentiation activity making them less useful as clinical AML differentiation agents. Here, we describe the discovery of a novel GSK3 inhibitor, GS87. GS87 was discovered in efforts to optimize GSK3 inhibition for AML differentiation activity. Despite GS87's dramatic ability to induce AML differentiation, kinase profiling reveals its high specificity in targeting GSK3 as compared with other kinases. GS87 demonstrates high efficacy in a mouse AML model system and unlike current AML therapeutics, exhibits little effect on normal bone marrow cells. GS87 induces potent differentiation by more effectively activating GSK3-dependent signaling components including MAPK signaling as compared with other GSK3 inhibitors. GS87 is a novel GSK3 inhibitor with therapeutic potential as a differentiation agent for non-promyelocytic AML. Mol Cancer Ther; 15(7); 1485-94. ©2016 AACR.

Identification of a Small Molecule That Overcomes HdmX-Mediated Suppression of p53.

Inactivation of the p53 tumor suppressor by mutation or overexpression of negative regulators occurs frequently in cancer. As p53 plays a key role in regulating proliferation or apoptosis in response to DNA-damaging chemotherapies, strategies aimed at reactivating p53 are increasingly being sought. Strategies to reactivate wild-type p53 include the use of small molecules capable of releasing wild-type p53 from key, cellular negative regulators, such as Hdm2 and HdmX. Derivatives of the Hdm2 antagonist Nutlin-3 are in clinical trials. However, Nutlin-3 specifically disrupts Hdm2-p53, leaving tumors harboring high levels of HdmX resistant to Nutlin-3 treatment. Here, we identify CTX1, a novel small molecule that overcomes HdmX-mediated p53 repression. CTX1 binds directly to HdmX to prevent p53-HdmX complex formation, resulting in the rapid induction of p53 in a DNA damage-independent manner. Treatment of a panel of cancer cells with CTX1 induced apoptosis or suppressed proliferation and, importantly, CTX1 demonstrates promising activity as a single agent in a mouse model of circulating primary human leukemia. CTX1 is a small molecule HdmX inhibitor that demonstrates promise as a cancer therapeutic candidate. Mol Cancer Ther; 15(4); 574-82. ©2016 AACR.

Aberrant Notch Signaling in the Bone Marrow Microenvironment of Acute Lymphoid Leukemia Suppresses Osteoblast-Mediated Support of Hematopoietic Niche Function.

More than half of T-cell acute lymphoblastic leukemia (T-ALL) patients harbor gain-of-function mutations in the intracellular domain of Notch1. Diffuse infiltration of the bone marrow commonly occurs in T-ALL and relapsed B-cell acute lymphoblastic leukemia patients, and is associated with worse prognosis. However, the mechanism of leukemia outgrowth in the marrow and the resulting biologic impact on hematopoiesis are poorly understood. Here, we investigated targetable cellular and molecular abnormalities in leukemia marrow stroma responsible for the suppression of normal hematopoiesis using a T-ALL mouse model and human T-ALL xenografts. We found that actively proliferating leukemia cells inhibited normal hematopoietic stem and progenitor cell (HSPC) proliferation and homing to the perivascular region. In addition, leukemia development was accompanied by the suppression of the endosteum-lining osteoblast population. We further demonstrated that aberrant Notch activation in the stroma plays an important role in negatively regulating the expression of CXLC12 on osteoblasts and their differentiation. Notch blockade reversed attenuated HSPC cycling, leukemia-associated abnormal blood lineage distribution, and thrombocytopenia as well as recovered osteoblast and HSPC abundance and improved the hematopoietic-supportive functions of osteoblasts. Finally, we confirmed that reduced osteoblast frequency and enhanced Notch signaling were also features of the marrow stroma of human ALL tissues. Collectively, our findings suggest that therapeutically targeting the leukemia-infiltrated hematopoietic niche may restore HSPC homeostasis and improve the outcome of ALL patients.

The role of TLR8 signaling in acute myeloid leukemia differentiation.

Acute myeloid leukemia (AML) is an aggressive disease with a poor 5-year survival of 21% that is characterized by the differentiation arrest of immature myeloid cells. For a rare subtype of AML (acute promyeloctyic leukemia, 5-10% of cases), all-trans retinoic acid therapy removes the differentiation block, yielding over a 90% cure rate. However, this treatment is not effective for the other 90-95% of AML patients, suggesting that new differentiation strategies are needed. Interestingly, differentiation is induced in normal hematopoietic cells through Toll-like receptor (TLR) stimulation and TLRs are expressed on AML cells. We present evidence that the TLR8 activation promotes AML differentiation and growth inhibition in a TLR8/MyD88/p38-dependent manner. We also show that that TLR7/TLR8 agonist, R848, considerably impairs the growth of human AML cells in immunodeficient mice. Our data suggests TLR8 activation has direct anti-leukemic effects independent of its immunomodulating properties that are currently under investigation for cancer therapy. Taken together, our results suggest that treatment with TLR8 agonists may be a promising new therapeutic strategy for AML.