Perceptions of Infertility and Semen Analysis Testing Among American Men Without Children.

OBJECTIVE: To determine whether health-conscious men are more likely to be concerned about infertility and self-initiate semen analysis at a laboratory/clinic or through a direct-to-consumer at-home product without a health care provider recommendation. METHODS: Cross-sectional survey conducted online via ResearchMatch.org between November 2019 and January 2020. Men age 18 and older without children (n = 634) were included for analysis. Outcomes were likelihood of self-initiating a semen analysis, prevalence of infertility concern. RESULTS: Of the 634 participants, 186 expressed concern about infertility but only 29% were likely to discuss these concerns with a health care provider. More men would self-initiate a semen analysis using an at-home product than through a traditional laboratory/clinic (14.2% vs 10.4%, P = .04). Odds of self-initiating a traditional semen analysis were higher for men concerned about low testosterone (odds ratio [OR] 2.30, 95% confidence interval [CI] 1.12-4.74, P = .023) and infertility (OR 3.91, 95% CI 2.14-7.15, P <.001). Self-initiating an at-home semen analysis was associated with concern for low testosterone and infertility as well as middle age (age 40-59: OR 3.02, 95% CI 1.16-7.88, P = .024) and fitness tracker use (OR: 1.95, 95% CI 1.12-3.39, P = .018). CONCLUSION: Many men were unlikely to discuss infertility concerns with a health care provider. Middle aged men and those who used fitness trackers were more likely to self-initiate fertility evaluation through at-home semen analysis. Concern about low serum testosterone was pervasive and strongly associated with concern for being infertile and self-initiating a semen analysis of any kind.

A Role for Tryptophan-2,3-dioxygenase in CD8 T-cell Suppression and Evidence of Tryptophan Catabolism in Breast Cancer Patient Plasma.

Tryptophan catabolism is an attractive target for reducing tumor progression and improving antitumor immunity in multiple cancers. Tumor infiltration by CD8 T cells correlates with improved prognosis in triple-negative breast cancer (TNBC) and a significant effort is underway to improve CD8 T-cell antitumor activity. In this study, primary human immune cells were isolated from the peripheral blood of patients and used to demonstrate that the tryptophan catabolite kynurenine induces CD8 T-cell death. Furthermore, it is demonstrated that anchorage-independent TNBC utilizes the tryptophan-catabolizing enzyme tryptophan 2,3-dioxygenase (TDO) to inhibit CD8 T-cell viability. Publicly available data revealed that high TDO2, the gene encoding TDO, correlates with poor breast cancer clinical outcomes, including overall survival and distant metastasis-free survival, while expression of the gene encoding the more commonly studied tryptophan-catabolizing enzyme, IDO1 did not. Metabolomic analysis, using quantitative mass spectrometry, of tryptophan and its catabolites, including kynurenine, in the plasma from presurgical breast cancer patients (n = 77) and 40 cancer-free donors (n = 40) indicated a strong correlation between substrate and catabolite in both groups. Interestingly, both tryptophan and kynurenine were lower in the plasma from patients with breast cancer compared with controls, particularly in women with estrogen receptor (ER)-negative and stage III and IV breast cancer. IMPLICATIONS: This study underscores the importance of tryptophan catabolism, particularly in aggressive disease, and suggests that future pharmacologic efforts should focus on developing drugs that target both TDO and IDO1.

Reversal of Triple-Negative Breast Cancer EMT by miR-200c Decreases Tryptophan Catabolism and a Program of Immunosuppression.

Tryptophan-2,3-dioxygenase (TDO2), a rate-limiting enzyme in the tryptophan catabolism pathway, is induced in triple-negative breast cancer (TNBC) by inflammatory signals and anchorage-independent conditions. TNBCs express extremely low levels of the miR-200 family compared with estrogen receptor-positive (ER+) breast cancer. In normal epithelial cells and ER+ breast cancers and cell lines, high levels of the family member miR-200c serve to target and repress genes involved in epithelial-to-mesenchymal transition (EMT). To identify mechanism(s) that permit TNBC to express TDO2 and other proteins not expressed in the more well-differentiated ER+ breast cancers, miRNA-200c was restored in TNBC cell lines. The data demonstrate that miR-200c targeted TDO2 directly resulting in reduced production of the immunosuppressive metabolite kynurenine. Furthermore, in addition to reversing a classic EMT signature, miR-200c repressed many genes encoding immunosuppressive factors including CD274/CD273, HMOX-1, and GDF15. Restoration of miR-200c revealed a mechanism, whereby TNBC hijacks a gene expression program reminiscent of that used by trophoblasts to suppress the maternal immune system to ensure fetal tolerance during pregnancy. IMPLICATIONS: Knowledge of the regulation of tumor-derived immunosuppressive factors will facilitate development of novel therapeutic strategies that complement current immunotherapy to reduce mortality for patients with TNBC.

Androgen Receptor Supports an Anchorage-Independent, Cancer Stem Cell-like Population in Triple-Negative Breast Cancer.

Preclinical and early clinical trials indicate that up to 50% of triple-negative breast cancers (TNBC) express androgen receptor (AR) and are potentially responsive to antiandrogens. However, the function of AR in TNBC and the mechanisms by which AR-targeted therapy reduces tumor burden are largely unknown. We hypothesized that AR maintains a cancer stem cell (CSC)-like tumor-initiating population and serves as an antiapoptotic factor, facilitating anchorage independence and metastasis. AR levels increased in TNBC cells grown in forced suspension culture compared with those in attached conditions, and cells that expressed AR resisted detachment-induced apoptosis. Culturing TNBC cells in suspension increased the CSC-like population, an effect reversed by AR inhibition. Pretreatment with enzalutamide (Enza) decreased the tumor-initiating capacity of TNBC cells and reduced tumor volume and viability when administered simultaneously or subsequent to the chemotherapeutic paclitaxel; simultaneous treatment more effectively suppressed tumor recurrence. Overall, our findings suggest that AR-targeted therapies may enhance the efficacy of chemotherapy even in TNBCs with low AR expression by targeting a CSC-like cell population with anchorage independence and invasive potential. Cancer Res; 77(13); 3455-66. ©2017 AACR.

Morphine paradoxically prolongs neuropathic pain in rats by amplifying spinal NLRP3 inflammasome activation.

Opioid use for pain management has dramatically increased, with little assessment of potential pathophysiological consequences for the primary pain condition. Here, a short course of morphine, starting 10 d after injury in male rats, paradoxically and remarkably doubled the duration of chronic constriction injury (CCI)-allodynia, months after morphine ceased. No such effect of opioids on neuropathic pain has previously been reported. Using pharmacologic and genetic approaches, we discovered that the initiation and maintenance of this multimonth prolongation of neuropathic pain was mediated by a previously unidentified mechanism for spinal cord and pain-namely, morphine-induced spinal NOD-like receptor protein 3 (NLRP3) inflammasomes and associated release of interleukin-1ß (IL-1ß). As spinal dorsal horn microglia expressed this signaling platform, these cells were selectively inhibited in vivo after transfection with a novel Designer Receptor Exclusively Activated by Designer Drugs (DREADD). Multiday treatment with the DREADD-specific ligand clozapine-N-oxide prevented and enduringly reversed morphine-induced persistent sensitization for weeks to months after cessation of clozapine-N-oxide. These data demonstrate both the critical importance of microglia and that maintenance of chronic pain created by early exposure to opioids can be disrupted, resetting pain to normal. These data also provide strong support for the recent "two-hit hypothesis" of microglial priming, leading to exaggerated reactivity after the second challenge, documented here in the context of nerve injury followed by morphine. This study predicts that prolonged pain is an unrealized and clinically concerning consequence of the abundant use of opioids in chronic pain.

A TDO2-AhR signaling axis facilitates anoikis resistance and metastasis in triple-negative breast cancer.

The ability of a cancer cell to develop resistance to anoikis, a programmed cell death process triggered by substratum detachment, is a critical step in the metastatic cascade. Triple-negative breast cancers (TNBC) exhibit higher rates of metastasis after diagnosis, relative to estrogen-positive breast cancers, but while TNBC cells are relatively more resistant to anoikis, the mechanisms involved are unclear. Through gene expression and metabolomic profiling of TNBC cells in forced suspension culture, we identified a molecular pathway critical for anchorage-independent cell survival. TNBC cells in suspension upregulated multiple genes in the kynurenine pathway of tryptophan catabolism, including the enzyme tryptophan 2,3-dioxygenase (TDO2), in an NF-κB-dependent manner. Kynurenine production mediated by TDO2 in TNBC cells was sufficient to activate aryl hydrocarbon receptor (AhR), an endogenous kynurenine receptor. Notably, pharmacologic inhibition or genetic attenuation of TDO2 or AhR increased cellular sensitivity to anoikis, and also reduced proliferation, migration, and invasion of TNBC cells. In vivo, TDO2 inhibitor-treated TNBC cells inhibited colonization of the lung, suggesting that TDO2 enhanced metastatic capacity. In clinical specimens of TNBC, elevated expression of TDO2 was associated with increased disease grade, estrogen receptor-negative status, and shorter overall survival. Our results define an NF-κB-regulated signaling axis that promotes anoikis resistance, suggest functional connections with inflammatory modulation by the kynurenine pathway, and highlight TDO2 as an attractive target for treatment of this aggressive breast cancer subtype.