Sexual dimorphism in solid and hematological malignancies

OncoSexome: the landscape of sex-based differences in oncologic diseases

The NIH policy on sex as biological variable (SABV) emphasized the importance of sex-based differences in precision oncology. Over 50% of clinically actionable oncology genes are sex-biased, indicating differences in drug efficacy. Research has identified sex differences in non-reproductive cancers, highlighting the need for comprehensive sex-based cancer data. We therefore developed OncoSexome, a multidimensional knowledge base describing sex-based differences in cancer (https://idrblab.org/OncoSexome/) across four key topics: antineoplastic drugs and responses (SDR), oncology-related biomarkers (SBM), risk factors (SRF) and microbial landscape (SML). SDR covers sex-based differences in 2051 anticancer drugs; SBM describes 12 551 sex-differential biomarkers; SRF illustrates 350 sex-dependent risk factors; SML demonstrates 1386 microbes with sex-differential abundances associated with cancer development. OncoSexome is unique in illuminating multifaceted influences of biological sex on cancer, providing both external and endogenous contributors to cancer development and describing sex-based differences for the broadest oncological classes. Given the increasing global research interest in sex-based differences, OncoSexome is expected to impact future precision oncology practices significantly.

Sex-dependent niche responses modulate steady-state and regenerative hematopoiesis

Hematopoietic stem cells (HSCs) adapt to organismal blood production needs by balancing self-renewal and differentiation, adjusting to physiological demands and external stimuli. Although sex differences have been implicated in differential hematopoietic function in males versus females, the mediators responsible for these effects require further study. Here, we characterized hematopoiesis at a steady state and during regeneration following hematopoietic stem cell transplantation (HST). RNA sequencing of lineage(-) bone marrow cells from C57/Bl6 mice revealed a broad transcriptional similarity between the sexes. However, we identified distinct sex differences in key biological pathways, with female cells showing reduced expression of signatures involved in inflammation and enrichment of genes related to glycolysis, hypoxia, and cell cycle regulation, suggesting a more quiescent and less inflammatory profile compared with male cells. To determine the functional impacts of the observed transcriptomic differences, we performed sex-matched and mismatched transplantation studies of lineage(-) donor cells. During short-term 56-day HST recovery, we found a male donor cell proliferative advantage, coinciding with elevated serum TNF-α, and a male recipient engraftment advantage, coinciding with increased serum CXCL12. Together, we show that sex-specific cell responses, marked by differing expression of pathways regulating metabolism, hypoxia, and inflammation, shape normal and regenerative hematopoiesis, with implications for the clinical understanding of hematopoietic function.

A retrospective study of intravenous pentamidine for Pneumocystis jirovecii pneumonia prophylaxis in adult patients with hematologic malignancies-its utility during respiratory virus pandemics

OBJECTIVES

In hematology, prophylaxis for Pneumocystis jirovecii pneumonia (PCP) is recommended for patients undergoing hematopoietic stem cell transplantation and in selected categories of intensive chemotherapy for hematologic malignancies. Trimethoprim-sulfamethoxazole (TMP-SMX) is the recommended first-line agent; however, its use is not straightforward. Inhaled pentamidine is the recommended second-line agent; however, aerosolized medications were discouraged during respiratory virus outbreaks, especially during the COVID-19 pandemic, in view of potential contamination risks. Intravenous (IV) pentamidine is a potential alternative agent. We evaluated the effectiveness and tolerability of IV pentamidine use for PCP prophylaxis in adult allogeneic hematopoietic stem cell transplantation recipients and patients with hematologic malignancies during COVID-19.

RESULTS

A total of 202 unique patients who received 239 courses of IV pentamidine, with a median of three doses received (1-29). The largest group of the patients (49.5%) who received IV pentamidine were undergoing or had received a hematopoietic stem cell transplant. The most common reason for not using TMP-SMX prophylaxis was cytopenia (34.7%). We have no patients who had breakthrough PCP infection while on IV pentamidine. None of the patients developed an infusion reaction or experienced adverse effects from IV pentamidine.

CONCLUSIONS

Pentamidine administered IV monthly is safe and effective.

Infectious Diseases and Secondary Antibody Deficiency in Patients from a Mesoregion of São Paulo State, Brazil

Our aim was to determine the secondary antibody deficiency (SAD) profiles of patients in a mesoregion of São Paulo state, Brazil, focusing on infectious diseases. Demographic characteristics, and clinical and laboratory data were obtained from electronic files; infections were classified as organ-specific and graded as mild, moderate, life-threatening, and fatal. Non-Hodgkin's lymphoma (NHL) accounted for 30% of patients, nephrotic syndrome (NS) 25%, chronic lymphocyte leukemia 20%, and multiple myeloma 15%. Patients with NS were younger than those in other groups, and hypo-γ-globulinemia was detected in 94.1%, IgG < 400 mg/dL in 60.0%, IgA < 40 mg/dL in 55.0%, and CD19 < 20 cells/mm3 in 30.0%. One hundred and one infections were found; 82.1% were classified as mild or moderate, 7.9% as life-threatening, and 3.0% as fatal. Respiratory tract infections were more prevalent (41.5%), and pneumonia accounted for 19.8%. Lower levels of infections were found in patients with NS compared with NHL (p = 0.0001). Most patients progressed to hypo-γ-globulinemia and SAD after treatment with immunosuppressants, and mild and moderate infections were predominant. These therapies are increasing in patients with different diseases; therefore, monitoring hypo-γ-globulinemia and infections may help to identify patients at high risk for severe complications, antibiotic prophylaxis or treatment, and immunoglobulin replacement.

Ocular toxicities in chimeric antigen receptor T-cell therapy: a real-world study leveraging FAERS database

Aim: The purpose of this study was to comprehensively explore the ocular toxicity associated with chimeric antigen receptor (CAR) T-cell therapy. Materials & methods: Data were assembled from the US FDA's Adverse Event Reporting System (FAERS) database from 2017 to 2023. Information component and reporting odds ratio methods were used for signal detection in total/categorized CAR T-cell therapy. Results: A total of 17 positive signals (preferred term) were detected, yet none of them were documented in the product information. Some adverse events were with death outcomes and overlapped a lot with cytokine-release syndrome. Conclusion: The ocular adverse events associated with CAR-T cell therapy are noteworthy, and it is imperative to maintain increased alertness and institute early intervention strategies.

Tamoxifen for the treatment of myeloproliferative neoplasms: A Phase II clinical trial and exploratory analysis

Current therapies for myeloproliferative neoplasms (MPNs) improve symptoms but have limited effect on tumor size. In preclinical studies, tamoxifen restored normal apoptosis in mutated hematopoietic stem/progenitor cells (HSPCs). TAMARIN Phase-II, multicenter, single-arm clinical trial assessed tamoxifen's safety and activity in patients with stable MPNs, no prior thrombotic events and mutated JAK2V617F, CALRins5 or CALRdel52 peripheral blood allele burden ≥20% (EudraCT 2015-005497-38). 38 patients were recruited over 112w and 32 completed 24w-treatment. The study's A'herns success criteria were met as the primary outcome ( ≥ 50% reduction in mutant allele burden at 24w) was observed in 3/38 patients. Secondary outcomes included ≥25% reduction at 24w (5/38), ≥50% reduction at 12w (0/38), thrombotic events (2/38), toxicities, hematological response, proportion of patients in each IWG-MRT response category and ELN response criteria. As exploratory outcomes, baseline analysis of HSPC transcriptome segregates responders and non-responders, suggesting a predictive signature. In responder HSPCs, longitudinal analysis shows high baseline expression of JAK-STAT signaling and oxidative phosphorylation genes, which are downregulated by tamoxifen. We further demonstrate in preclinical studies that in JAK2V617F+ cells, 4-hydroxytamoxifen inhibits mitochondrial complex-I, activates integrated stress response and decreases pathogenic JAK2-signaling. These results warrant further investigation of tamoxifen in MPN, with careful consideration of thrombotic risk.

Clinical characteristics of bloodstream infections in adult patients with solid tumours and a nomogram for mortality prediction: a 5-year case-controlled retrospective study in a tertiary-level hospital

Background

Bloodstream infections (BSIs) are one of the leading causes of death in cancer patients. Nevertheless, the risk factors of BSIs in solid tumors have rarely been ascertained adequately.

Methods

We conducted a single-center case-controlled retrospective study from 2017 to 2021 among adults with solid tumors in a tertiary-level hospital. The BSIs and control group were matched by the propensity score matching method. We found independent risk factors of occurrence and death of BSIs using univariate and multivariate regression analysis. Additionally, a nomogram was constructed to predict the risk of mortality in BSIs.

Results

Of 602 patients with solid tumors in the study period, 186 had BSIs and 416 had non-BSIs. The incidence of BSIs was 2.0/1,000 admissions (206/102,704), and the 30-day mortality rate was 18.8% (35/186). Compared to the control group, the BSIs had longer hospital stays (24.5 days vs. 20.0 days), and higher frequency complicating with organ failure (10.5% vs. 2.4%), nephropathy (19.6% vs. 3.8%), comorbidities≥3 (35.5% vs. 20.0%), and liver-biliary-pancreatic infections (15.6% vs. 5.3%) (all P<0.001). Among the 186 patients with BSIs, 35 died within 30 days after BSIs. Gram-negative bacteria were the most frequent microorganisms (124/192, 64.6%). Liver cancer, organ failure, a high level of lactate dehydrogenase and septic shock were the independent hazardous factors for death of BSIs. What's more, a nomogram was constructed to predict the 30-day survival rate of BSIs, which was proved to have good accuracy (AUC: 0.854; 95% confidence interval: 0.785~0923) and consistency.

Conclusion

Being aware of the risk factors of BSIs redounds to take preventive measures to reduce the incidence and death of BSIs.

Differential expression of KCNQ1 and ATP4A genes according to the sex and age in the stomach

We compared the expression of six genes in stomach tissue samples between healthy men and women in different age groups to study sexually dimorphic gene expression. Real-Time RT-PCR was used to compare gene expression between men and women. Our results showed that the expression of KCNQ1 (p = 0.01) was significantly higher in non-menopausal women compared to post-menopausal women. In addition, the expression level of the ATP4A gene in men under 35 years was significantly higher than in men above 50 (p = 0.026). Sexually and age dimorphic gene expression in some genes throughout life may affect gastric function.

Latexin regulates sex dimorphism in hematopoiesis via gender-specific differential expression of microRNA 98-3p and thrombospondin 1

Hematopoietic stem cells (HSCs) have the ability to self-renew and differentiate to all blood cell types. HSCs and their differentiated progeny show sex/gender differences. The fundamental mechanisms remain largely unexplored. We previously reported that latexin (Lxn) deletion increased HSC survival and repopulation capacity in female mice. Here, we find no differences in HSC function and hematopoiesis in Lxn knockout (Lxn-/-) male mice under physiologic and myelosuppressive conditions. We further find that Thbs1, a downstream target gene of Lxn in female HSCs, is repressed in male HSCs. Male-specific high expression of microRNA 98-3p (miR98-3p) contributes to Thbs1 suppression in male HSCs, thus abrogating the functional effect of Lxn in male HSCs and hematopoiesis. These findings uncover a regulatory mechanism involving a sex-chromosome-related microRNA and its differential control of Lxn-Thbs1 signaling in hematopoiesis and shed light on the process underlying sex dimorphism in both normal and malignant hematopoiesis.

Sex differences in adults with acute myeloid leukemia and the impact of sex on overall survival

BACKGROUND

There is a male predominance of acute myeloid leukemia (AML) incidence, but survival data are conflicting. The objective of this study is to carry out a comprehensive analysis of sex differences in AML, and to investigate the impact of sex disparities in survival.

METHODS

The cohort included patients ≥18 years diagnosed with AML (2010-2022). Demographics, treatment patterns, treatment adverse events, and survival were analyzed. The population was described and compared by sex, and sex-based risks and associations were obtained via Cox proportional-hazards regression.

RESULTS

In total, 1020 AML patients were analyzed (57.4% males), with lower risk of death for females (aHR = 0.41, 95% CI 0.26-0.66). Among females, BMT (aHR = 0.51, 95% CI 0.27-0.97), hospitalization record (aHR = 0.65, 95%CI 0.45-0.93), and higher appointment completion rates (aHR = 0.98, 95% CI 0.98-0.98) were associated with lower risk of death. Overall, and similarly in males, higher age at diagnosis (aHR = 1.03, 95% CI 1.02-1.04) and a TP53 mutation (aHR = 2.24, 95% CI 1.69-2.97) were associated with higher risk of death.

CONCLUSION

Sex differences exist in both AML incidence and overall survival. Treatment and health care factors should be addressed by caregivers and public policies developed to reduce mortality rates and mitigate existing sex differences.

Incidence and survival of lymphoid neoplasms in Spain, 2002-2013: A population-based study from the Spanish Network of Cancer Registries (REDECAN)

Introduction

The aim of this study was to describe incidence, incidence trends and survival patterns of lymphoid neoplasms (LNs) and its subtypes in Spain in the period 2002-2013 using data from the Spanish Network of Cancer Registries (REDECAN).

Materials and Methods

Data were extracted from 13 Spanish population-based cancer registries. LNs incident cases were codified using the International Classification of Diseases for Oncology, third edition (ICD-O-3) and grouped according to the WHO 2008 classification. Age-standardized incidence rates to the 2013 European standard population (ASIRe) were obtained. Poisson regression models were used to analyze trends in incidence rates and estimate the annual percentage change (APC) for each subtype. The number of cases in Spain for 2023 was estimated by applying the estimated age-specific rates for the year 2023 to the 2023 Spanish population. Observed survival (OS) was estimated by the Kaplan-Meier method and net survival (NS) by the Pohar-Perme method. Sex- and age-specific estimates of 5-year NS were calculated, as well as its changes according to two periods of diagnosis (2002-2007 and 2008-2013).

Results

LNs accounted for 69% (n=39,156) of all hematological malignancies (n=56,751) diagnosed during the period of study. Median age at diagnosis was 67 years (interquartile range (IQR) = 52-77). The overall ASIRe was 34.23 (95% confidence interval (CI): 33.89, 34.57) and showed a marked male predominance in almost all subtypes (global sex ratio = 1.45). During the study period, incidence trends of LNs remained stable (APC: 0.3; 95% CI: -0.1, 0.6), nevertheless some subtypes showed statistically significant variations, such as LNs NOS category (APC: -5.6; 95% CI: -6.8, -4.3). Around 17,926 new cases of LNs will be diagnosed in 2023 in Spain. Survival rates differed considerably across age-groups, while they were similar between men and women. Five- year NS was 62.81% (95% CI: 62.1, 63.52) for all LNs, and varied widely across LNs subtypes, ranging from 39.21% to 90.25%. NS for all LNs improved from the first period of diagnosis to the second one, being 61.57% (95% CI: 60.56, 62.61) in 2002-2007 and 64.17% (95% CI: 63.29, 65.07) in 2008-2013.

Conclusions

This study presents the first complete and extensive population-based analysis of LNs incidence and survival in Spain. These population-based data provide relevant information to better understand the epidemiology of LNs in Southern Europe and it features some useful points for public health authorities and clinicians. However, additional improvements regarding the registration of these hematological neoplasms can be implemented.

Hematological Effects and Benchmark Doses of Long-Term Co-Exposure to Benzene, Toluene, and Xylenes in a Follow-Up Study on Petrochemical Workers

Benzene, toluene, and xylenes (BTX) commonly co-exist. Exposure to individual components and BTX-rich mixtures can induce hematological effects. However, the hematological effects of long-term exposure to BTX are still unclear, and respective reference levels based on empirical evidence should be developed. We conducted a follow-up study in BTX-exposed petrochemical workers. Long-term exposure levels were quantified by measuring cumulative exposure (CE). Generalized weighted quantile sum (WQS) regression models and Benchmark Dose (BMD) Software were used to evaluate their combined effects and calculate their BMDs, respectively. Many hematologic parameters were significantly decreased at the four-year follow-up (p < 0.05). We found positive associations of CE levels of benzene, toluene, and xylene with the decline in monocyte counts, lymphocyte counts, and hematocrit, respectively (β > 0.010, Ptrend < 0.05). These associations were stronger in subjects with higher baseline parameters, males, drinkers, or overweight subjects (Pinteraction < 0.05). BTX had positive combined effects on the decline in monocyte counts, red-blood-cell counts, and hemoglobin concentrations (Ptrend for WQS indices < 0.05). The estimated BMDs for CE levels of benzene, toluene, and xylene were 2.138, 1.449, and 2.937 mg/m3 × year, respectively. Our study demonstrated the hematological effects of long-term BTX co-exposure and developed 8h-RELs of about 0.01 ppm based on their hematological effects.

Sex differences in normal and malignant hematopoiesis

Hematopoiesis is a continuous and well-regulated process requiring both the capacity for self-renewal and the potential for differentiation of hematopoietic stem cells. Multiple studies indicate that sex hormones exert significant effects on not only hematopoietic stem and progenitor cells, but also the development of hematopoietic lineages, resulting in sexual dimorphisms in normal hematopoiesis. Hematologic malignancies comprise a wide variety of cancers affecting the blood, bone marrow, and lymphatic system, such as leukemia, lymphoma, myeloma, myelodysplastic syndrome, and myeloproliferative diseases. Overall, males are at greater risk and have worse prognosis for most of these malignancies compared with females. A better understanding of the differences between male and female could be of substantial value in research as well as clinical management.

A biological approach to adult sex differences in skeletal indicators of childhood stress

OBJECTIVES

In previous work examining the etiology of cribra orbitalia (CO) and porotic hyperostosis (PH) in a contemporary juvenile mortality sample, we noted that males had higher odds of having CO lesions than females. Here, we examine potential reasons for this pattern in greater detail. Four non-mutually exclusive mechanisms could explain the observed sex differences: (1) sex-biased mortality; (2) sexual dimorphism in immune responses; (3) sexual dimorphism in bone turnover; or (4) sexual dimorphism in marrow conversion.

SUBJECTS AND METHODS

The sample consists of postmortem computed tomography scans and autopsy reports, field reports, and limited medical records of 488 individuals from New Mexico (203 females; 285 males) aged between 0.5 and 15 years. We used Kaplan-Meier survival analysis, predicted probabilities, and odds ratios to test each mechanism.

RESULTS

Males do not have lower survival probabilities than females, and we find no indications of sex differences in immune response. Overall, males have a higher probability of having CO or PH lesions than females.

CONCLUSIONS

All results indicate that lesion formation in juveniles is influenced by some combination of sex differences in the pace of red-yellow conversion of the bone marrow and bone turnover. The preponderance of males with CO and PH likely speaks to the potential for heightened osteoblastic activity in males. We find no support for the hypotheses that sex biases in mortality or immune responses impacted lesion frequency in this sample. Sex differences in biological processes experienced by children may affect lesion formation and lesion expression in later life.

Immune Sexual Dimorphism: Connecting the Dots

Despite numerous studies of immune sexual dimorphism, sexual differences are not rigorously mapped and dimorphic mechanisms are incompletely understood. Current immune research typically studies sex differences in specific cells, tissues, or diseases but without providing an integrated picture. To connect the dots, we suggest comprehensive research approaches to better our understanding of immune sexual dimorphism and its mechanisms.

Sex-Based Differences in the Tumor Microenvironment

Cancers are heterogeneous multifactorial diseases consisting of a major public health issue worldwide. Sex disparities are evidenced in cancer incidence, mortality, expression of prognosis factor, response to treatment, and survival. For both sexes, an interplay of intrinsic and environmental factors influences cancer cells and tumor microenvironment (TME) components. The TME cumulates both supportive and communicative functions, contributing to cancer development, progression, and metastasis dissemination. The frontline topics of this chapter are focused on the contribution of sex, via steroid hormones, such as estrogens and androgens, on the following components of the TME: cancer-associated fibroblasts (CAFs), extracellular matrix (ECM), blood and lymphatic endothelial cells, and immunity/inflammatory system.

[Gender blindness in medical textbooks: the case of leukemias]

OBJECTIVE

To analyse the existence of sex-differences in the content on leukemias in the Haematology and Internal Medicine textbooks recommended in the Medical Degrees, 2019-2020, by comparison with the sex-differences recognized in the scientific literature.

METHOD

Manifest content analysis of the content of chapters on leukemias in the books on hematology and internal medicine, clinical haematology and haematology undergraduate. Analysis categories: epidemiology, etiopathogenesis, diagnosis, treatment and prognosis of leukemias.

RESULTS

Epidemiological information from the revised books has a greater consideration of sex differences in incidence and prognosis but does not contain data on mortality and survival. Etiopathogenesis is described in all books as the same physiological process for both sexes and no differences in the presentation of symptoms are described in any book. Three books describe a unique treatment that is assumed equal for both sexes; two books mention the treatment of acute myeloid leukemia in pregnant women and one in chronic myeloid leukemia. No book mentions sex-differences in pharmacokinetics, efficacy, or treatment toxicity, although there is greater evidence on unequal behavior between the sexes.

CONCLUSIONS

The contents of sex and gender differences in the leukemia chapters analyzed are insufficient compared to the evidence in the scientific literature today. Hematology textbooks might increase their scientific quality in future editions, including knowledge of sex-gender interaction in the sections of epidemiology, etiology, pathogenesis, diagnosis, treatment, prognosis, and consequences of leukemias, which will contribute to better professional practices, more efficient and equitable.

Association of RERG Expression with Female Survival Advantage in Malignant Pleural Mesothelioma

Sex differences in incidence, prognosis, and treatment response have been described for many cancers. In malignant pleural mesothelioma (MPM), a lethal disease associated with asbestos exposure, men outnumber women 4 to 1, but women consistently live longer than men following surgery-based therapy. This study investigated whether tumor expression of genes associated with estrogen signaling could potentially explain observed survival differences. Two microarray datasets of MPM tumors were analyzed to discover estrogen-related genes associated with survival. A validation cohort of MPM tumors was selected to balance the numbers of men and women and control for competing prognostic influences. The RAS like estrogen regulated growth inhibitor (RERG) gene was identified as the most differentially-expressed estrogen-related gene in these tumors and predicted prognosis in discovery datasets. In the sex-matched validation cohort, low RERG expression was significantly associated with increased risk of death among women. No association between RERG expression and survival was found among men, and no relationship between estrogen receptor protein or gene expression and survival was found for either sex. Additional investigations are needed to elucidate the molecular mechanisms underlying this association and its sex specificity.

Effects of Clinicopathological Characteristics on the Survival of Patients Treated with PD-1/PD-L1 Inhibitor Monotherapy or Combination Therapy for Advanced Cancer: A Systemic Review and Meta-Analysis

Background

PD-1/PD-L1 inhibitors have made unprecedented progress in the treatment of cancer.

Methods

A systemic search was conducted for randomized controlled trials that compared PD-1/PD-L1 inhibitor monotherapy or combination therapy with nonimmunotherapy. Hazard ratios (HRs) of overall survival (OS) according to the sex, age, ECOG PS, smoking status, liver metastasis, PD-L1 expression, EGFR, and KRAS status of patients were analyzed.

Results

Totally, 13 studies with monotherapy and 5 with combination regimens were included, and the pooled HRs of OS were 0.74 (P < 0.001) and 0.64 (P < 0.001), respectively. EGFR wild-type patients could benefit from immunotherapy monotherapy (HR, 0.77; P < 0.001) while those of the mutant type had no survival benefit (HR, 1.11; P = 0.54), and the difference was statistically significant (interaction, P = 0.005). KRAS wild-type patients had no survival benefit from monotherapy (HR, 0.89; P = 0.49). For combination therapy, both male and female derived benefits but female had a significantly reduced risk of death (HR, 0.45; P < 0.001) compared with male (HR, 0.73; P < 0.001; interaction, P = 0.004). Nonsmokers derived more survival benefits from combination therapy (HR, 0.29; P < 0.001) than smokers (HR, 0.63; P = 0.001; interaction, P = 0.02). No significant difference was found between age, ECOG PS, liver metastasis, PD-L1 expression, and OS of both PD-1/PD-L1 inhibitor monotherapy and combination therapy.

Conclusions

Both PD-1/PD-L1 inhibitor monotherapy and combination therapy significantly prolonged the OS of patients with advanced malignant tumors. EGFR status for monotherapy and sex and smoking status for combination therapy were important predictors of survival benefits.

Sexual dimorphism in aging hematopoiesis: an earlier decline of hematopoietic stem and progenitor cells in male than female mice

Adult hematopoietic stem and progenitor cells (HSPCs) reside in the bone marrow (BM) ensuring homeostasis of blood production and immune response throughout life. Sex differences in immunocompetence and mortality are well-documented in humans. However, whether HSPCs behave dimorphically between sexes during aging remains unknown. Here, we show that a significant expansion of BM-derived HSPCs occurs in the middle age of female but in the old age of male mice. We then show that a decline of HSPCs in male mice, as indicated by the expression levels of select hematopoietic genes, occurs much earlier in the aging process than that in female mice. Sex-mismatched heterochronic BM transplantations indicate that the middle-aged female BM microenvironment plays a pivotal role in sustaining hematopoietic gene expression during aging. Furthermore, a higher concentration of the pituitary sex hormone follicle-stimulating hormone (FSH) in the serum and a concomitant higher expression of its receptor on HSPCs in the middle-aged and old female mice than age-matched male mice, suggests that FSH may contribute to the sexual dimorphism in aging hematopoiesis. Our study reveals that HSPCs in the BM niches are possibly regulated in a sex-specific manner and influenced differently by sex hormones during aging hematopoiesis.

Influence of Androgens on Immunity to Self and Foreign: Effects on Immunity and Cancer

It is well-known that sex hormones can directly and indirectly influence immune cell function. Different studies support a suppressive role of androgens on different components of the immune system by decreasing antibody production, T cell proliferation, NK cytotoxicity, and stimulating the production of anti-inflammatory cytokines. Androgen receptors have also been detected in many different cells of hematopoietic origin leading to direct effects of their ligands on the development and function of the immune system. The immunosuppressive properties of androgens could contribute to gender dimorphisms in autoimmune and infectious disease and thereby also hamper immune surveillance of tumors. Consistently, females generally are more prone to autoimmunity, while relatively less susceptible to infections, and have lower incidence and mortality of the majority of cancers compared to males. Some studies show that androgen deprivation therapy (ADT) can induce expansion of naïve T cells and increase T-cell responses. Emerging clinical data also reveal that ADT might enhance the efficacy of various immunotherapies including immune checkpoint blockade. In this review, we will discuss the potential role of androgens and their receptors in the immune responses in the context of different diseases. A particular focus will be on cancer, highlighting the effect of androgens on immune surveillance, tumor biology and on the efficacy of anti-cancer therapies including emerging immune therapies.

The Relevance of Gender in Tumor-Influencing Epigenetic Traits

Tumorigenesis as well as the molecular orchestration of cancer progression are very complex mechanisms that comprise numerous elements of influence and regulation. Today, many of the major concepts are well described and a basic understanding of a tumor's fine-tuning is given. Throughout the last decade epigenetics has been featured in cancer research and it is now clear that the underlying mechanisms, especially DNA and histone modifications, are important regulators of carcinogenesis and tumor progression. Another key regulator, which is well known but has been neglected in scientific approaches as well as molecular diagnostics and, consequently, treatment conceptualization for a long time, is the subtle influence patient gender has on molecular processes. Naturally, this is greatly based on hormonal differences, but from an epigenetic point of view, the diverse susceptibility to stress and environmental influences is of prime interest. In this review we present the current view on which and how epigenetic modifications, emphasizing DNA methylation, regulate various tumor diseases. It is our aim to elucidate gender and epigenetics and their interconnectedness, which will contribute to understanding of the prospect molecular orchestration of cancer in individual tumors.