Estrogen Receptor β in Melanoma: From Molecular Insights to Potential Clinical Utility

Sex-dependent interaction of PTGS2 with miR-146a as risk factor for melanoma and the impact of sex hormones in gene expression in skin cells

Gender disparity in melanoma is a complex issue where sex hormones could be engaged. Differences in genetic variations are important in understanding the mechanisms of sex disparity in melanoma. Post-transcriptional regulation of prostaglandin-endoperoxide synthase (PTGS2) mRNA occurs through a complex interplay of specific trans-acting RNA-binding proteins and microRNAs. MiR-146a is a key player in melanoma, modulating immune responses and tumor microenvironment (TME). Polymorphisms in PTGS2 gene rs20415GC have been associated with an increased risk of melanoma. Epistasis between polymorphisms rs20415GC was investigated by genotyping 453 melanoma patients and 382 control individuals. The effects of testosterone and 17β-estradiol were analyzed in keratinocytes and two melanoma cell lines. The rs2910164GG showed a higher risk in the presence of the genotype rs20417CC in the male population. Testosterone and 17β-estradiol act differently on PTGS2 and miR-146a expression, depending on the cell type. Testosterone augments PTGS2 gene expression in keratinocytes and miR-146a in melanoma cells. While 17β-estradiol only increases miR-146a expression in HaCaT cells. The present study indicates a sex-specific relation between miR-146a and PTGS2 polymorphisms with melanoma cancer risk. Testosterone and 17β-estradiol act differently on the expression of PTGS2 and miR-146a depending on the skin cell type.

Melanoma and sex hormones: Pathogenesis, progressive disease and response to treatments

Cutaneous melanoma represents the fifth tumor in terms of incidence in young adults, with a major involvement of males than females. Despite the significant changes in available effective treatments for cutaneous melanoma, there is still a proportion of patients that do not benefit long-term disease control with immune checkpoint inhibitors and/or BRAF/MEK inhibitors, and eventually develop progressive disease. In addition to the emerging biomarkers under investigation to understand resistance to treatments, recent studies resumed the role of sex hormones (estrogens, progesterone and androgens) in melanoma patients. In the last decades, the impact of sex hormones has been considered controversial in melanoma patients, but actual growing preclinical and clinical evidence underline the potential influence on melanoma cells' growth, tumor microenvironment, the immune system and consequently on the course of disease.This review will provide available insights on the role of sex hormones in melanoma pathogenesis, disease progression and response/resistance to systemic treatments. We will also offer an overview on the recent studies on the theme, describing the hormonal contribution to disease response and the interaction with targeted therapies and immune-checkpoint inhibitors in cutaneous melanoma patients, illustrating an insight into future research in this field.

Synthesis and Anti-Melanoma Activity of Acryloyl Pyridinone Analogues

A major challenge for clinical management of melanoma is the prevention and treatment of metastatic disease. Drug discovery efforts over the last 10 years have resulted in several drugs that improve the prognosis of metastatic melanoma; however, most patients develop early resistance to these treatments. We designed and synthesized, through a concise synthetic strategy, a series of hybrid olefin-pyridinone compounds that consist of structural motifs from tamoxifen and ilicicolin H. These compounds were tested against a human melanoma cell line and patient-derived melanoma cells that had metastasized to the brain. Three compounds 7 b, 7 c, and 7 g demonstrated promising activity (IC50=0.4-4.3 μM). Cell cycle analysis demonstrated that 7 b and 7 c induce cell cycle arrest predominantly in the G1 phase. Both 7 b and 7c significantly inhibited migration of A375 melanoma cells; greater effects were demonstrated by 7 b. Molecular modelling analysis provides insight into a plausible mechanism of action.

The Association Between Pregnancy Timing and Cumulative Exposure on Survival in Melanoma

BACKGROUND

As melanoma is common among young women, the impact of pregnancy on melanoma prognosis is of interest.

OBJECTIVE

The purpose of this study was to examine the association between pregnancy and survival in female melanoma patients of childbearing age.

METHODS

We performed a population-level, retrospective cohort study of women of childbearing age (18-45 years) diagnosed with melanoma from 2007 to 2017 using administrative data from Ontario, Canada. Patients were categorized according to pregnancy status (i.e. pregnancy before [conception from 60 to 13 months prior to melanoma], pregnancy-associated [conception 12 months prior to and after], and pregnancy after [conception 12 months after] melanoma). Cox models were used to examine melanoma-specific survival (MSS) and overall survival (OS) associated with pregnancy status.

RESULTS

Of 1312 women with melanoma, most did not experience pregnancy (84.1%), with 7.6% experiencing a pregnancy-associated melanoma and 8.2% experiencing a pregnancy after melanoma. Pregnancy before melanoma occurred in 18.1% of patients. Pregnancy before (hazard ratio [HR] 0.67, 95% confidence interval [CI] 0.35-1.28), associated (HR 1.15, 95% CI 0.45-2.97), and after melanoma (HR 0.39, 95% CI 0.13-1.11) was not associated with a difference in MSS compared with those who did not experience a pregnancy during these time periods. Pregnancy status was also not associated with a difference in OS (p > 0.05). Cumulative weeks pregnant were not associated with a difference in MSS (4-week HR 0.99, 95% CI 0.92-1.07) or OS (4-week HR 1.00, 95% CI 0.94-1.06).

CONCLUSIONS

In this population-level analysis of female melanoma patients of childbearing age, pregnancy was not associated with a difference in survival, suggesting that pregnancy is not associated with a worse melanoma prognosis.

An estrogen response-related signature predicts response to immunotherapy in melanoma

Background

Estrogen/estrogen receptor signaling influences the tumor microenvironment and affects the efficacy of immunotherapy in some tumors, including melanoma. This study aimed to construct an estrogen response-related gene signature for predicting response to immunotherapy in melanoma.

Methods

RNA sequencing data of 4 immunotherapy-treated melanoma datasets and TCGA melanoma was obtained from open access repository. Differential expression analysis and pathway analysis were performed between immunotherapy responders and non-responders. Using dataset GSE91061 as the training group, a multivariate logistic regression model was built from estrogen response-related differential expression genes to predict the response to immunotherapy. The other 3 datasets of immunotherapy-treated melanoma were used as the validation group. The correlation was also examined between the prediction score from the model and immune cell infiltration estimated by xCell in the immunotherapy-treated and TCGA melanoma cases.

Results

"Hallmark Estrogen Response Late" was significantly downregulated in immunotherapy responders. 11 estrogen response-related genes were significantly differentially expressed between immunotherapy responders and non-responders, and were included in the multivariate logistic regression model. The AUC was 0.888 in the training group and 0.654-0.720 in the validation group. A higher 11-gene signature score was significantly correlated to increased infiltration of CD8+ T cells (rho=0.32, p=0.02). TCGA melanoma with a high signature score showed a significantly higher proportion of immune-enriched/fibrotic and immune-enriched/non-fibrotic microenvironment subtypes (p<0.001)-subtypes with better response to immunotherapy-and significantly better progression-free interval (p=0.021).

Conclusion

In this study, we identified and verified an 11-gene signature that could predict response to immunotherapy in melanoma and was correlated with tumor-infiltrating lymphocytes. Our study suggests targeting estrogen-related pathways may serve as a combination strategy for immunotherapy in melanoma.

Skin cancer incidence in transgender individuals receiving gender-affirming hormone treatment: a nationwide cohort study in the Netherlands

BACKGROUND

Development of skin cancer, in particular melanoma, has been linked to sex hormones. We aimed to determine the incidence of skin cancer in transgender individuals receiving gender-affirming hormone treatment (GAHT).

METHODS

In this nationwide retrospective cohort study, clinical information of participants who visited our clinic between (the years) 1972 and 2018 and received GAHT was integrated with national pathology and cancer statistics data in order to assess skin cancer incidence. Standardized incidence ratios (SIRs) were calculated.

RESULTS

The cohort consisted of 2,436 trans women and 1,444 trans men. The median age at the start of GAHT was 31 years (IQR 24-42) in trans women and 24 years (IQR 20-32) in trans men. The median follow-up time for trans women was 8 years (IQR 3-18) with a total follow-up time of 29,152 years and 4 years (IQR 2-12) with a total follow-up time of 12,469 years for trans men. Eight trans women were diagnosed with melanoma (SIR 1.80 [95% CI 0.83-3.41] vs. all men; SIR 1.40 [0.65-2.65] vs. all women), and seven developed squamous cell carcinoma (SIR 0.78 [0.34-1.55] vs. all men; SIR 1.15 [0.50-2.27] vs. all women). Two trans men developed melanoma (SIR 1.05 [0.18-3.47] vs. all men; SIR 0.77 [0.14-2.70] vs. all women).

CONCLUSIONS

GAHT did not appear to affect skin cancer incidence in this large cohort of transgender individuals. As skin cancer incidence increases with age and the proportion of elderly subjects is currently limited in this cohort, it will be worthwhile to repeat this analysis in the future.

The effect of menopausal hormone therapy on the risk of melanoma and keratinocyte skin cancer: A systematic review and meta-analysis of observational studies

BACKGROUND

Whether menopausal hormone therapy (MHT) increases the risk of skin cancer is controversial.

AIM

To systematically review and meta-analyze evidence regarding the association of MHT with the risk of melanoma and keratinocyte cancer (KC).

MATERIAL AND METHODS

A comprehensive literature search was conducted of the PubMed, Scopus and Cochrane databases, through to 30 October 2021. Skin neoplasms were divided into melanoma and KC. In the latter category, both basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) were considered. The results are presented as hazard ratios (HR) with 95 % confidence intervals (CI). The I² index was used to assess heterogeneity. Subgroup analysis and sensitivity analysis were also conducted in order to explore potential differences among studies.

RESULTS

Twenty-seven studies were included in the qualitative and 23 in the quantitative analysis, with a total of 2,612,712 menopausal women (25,126 with skin cancer; 20,150 with melanoma). MHT was associated with an increased risk of melanoma (HR 1.11; 95 % CI 1.05-1.19; I² 45%). With regard to MHT type, both estrogen monotherapy (HR 1.22, 95 % CI 1.16-1.29; I² 0%) and estrogen in combination with progestogen (HR 1.11, 95 % CI 1.05-1.18, I² 26%) significantly increased that risk. Regarding melanoma subtype, superficial spreading melanoma (SSM) and lentigo maligna melanoma (LMM) were the only histologic subtypes associated with MHT use. MHT was also associated with an increased risk of KC (HR 1.17, 95 % CI 1.04-1.31, I² 83%), specifically BCC (HR 1.22, 95 % CI 1.12-1.32; I² 29%). Longer duration (>5 years) of MHT, current use and estrogen monotherapy were associated with an increased KC risk compared with no use.

CONCLUSION

The use of MHT by postmenopausal women was associated with an increased risk of melanoma and KC. This risk was higher for current MHT users and those treated for over 5 years.

Aptamer-based Advances in Skin Cancer Research

Cancer diseases have been one of the biggest health threats for the last two decades. Approximately 9% of all diagnosed cancers are skin cancers, including melanoma and non-melanoma. In all cancer cases, early diagnosis is essential to achieve efficient treatment. New solutions and advanced techniques for rapid diagnosis are constantly being sought. Aptamers are single-stranded RNA or DNA synthetic sequences or peptides, which offer novel possibilities to this area of research by specifically binding selected molecules, the so-called cancer biomarkers. Nowadays, they are widely used as diagnostic probes in imaging and targeted therapy. In this review, we have summarized the recently made advances in diagnostics and treatment of skin cancers, which have been achieved by combining aptamers with basic or modern technologies.

Extracellular Acidosis Differentially Regulates Estrogen Receptor β-Dependent EMT Reprogramming in Female and Male Melanoma Cells

Clinical outcomes of melanoma patients pointed out a gender disparity that supports a correlation between sex hormone activity on estrogen receptors (ER) and melanoma development and progression. Here, we found that the epithelial-to-mesenchymal transition (EMT) of melanoma cells induced by extracellular acidosis, which is a crucial hallmark of solid cancers, correlates with the expression of ERβ, the most representative ER on melanoma cells. Extracellular acidosis induces an enhanced expression of ERβ in female cells and EMT markers remain unchanged, while extracellular acidosis did not induce the expression of ERβ in male cells and EMT was strongly promoted. An inverse relationship between ERβ expression and EMT markers in melanoma cells of different sex exposed to extracellular acidosis was revealed by two different technical approaches: florescence-activated cell sorting of high ERβ expressing cell subpopulations and ERβ receptor silencing. Finally, we found that ERβ regulates EMT through NF-κB activation. These results demonstrate that extracellular acidosis drives a differential ERβ regulation in male and female melanoma cells and that this gender disparity might open new perspectives for personalized therapeutic approaches.

BRAFV600E Mutation Enhances Estrogen-Induced Metastatic Potential of Thyroid Cancer by Regulating the Expression of Estrogen Receptors

BACKGRUOUND

Cross-talk between mitogen-activated protein kinase and estrogen has been reported; however, the role of BRAFV600E in the estrogen responsiveness of thyroid cancer is unknown. We elucidated the effect of BRAFV600E on the estrogen-induced increase in metastatic potential in thyroid cancer.

METHODS

Using a pair of cell lines, human thyroid cell lines which harbor wild type BRAF gene (Nthy/WT) and Nthy/BRAFV600E (Nthy/V600E), the expression of estrogen receptors (ERs) and estrogen-induced metastatic phenotypes were evaluated. Susceptibility to ERα- and ERβ-selective agents was evaluated to confirm differential ER expression. ESR expression was analyzed according to BRAFV600E status and age (≤50 years vs. >50 years) using The Cancer Genome Atlas (TCGA) data.

RESULTS

Estradiol increased the ERα/ERβ expression ratio in Nthy/V600E, whereas the decreased ERα/ERβ expression ratio was found in Nthy/WT. BRAFV600E-mutated cell lines showed a higher E2-induced increase in metastatic potential, including migration, invasion, and anchorage-independent growth compared with Nthy/WT. An ERα antagonist significantly inhibited migration in Nthy/V600E cells, whereas an ERβ agonist was more effective in Nthy/WT. In the BRAFV600E group, ESR1/ESR2 ratio was significantly higher in younger age group (≤50 years) compared with older age group (>50 years) by TCGA data analysis.

CONCLUSION

Our data show that BRAFV600E mutation plays a crucial role in the estrogen responsiveness of thyroid cancer by regulating ER expression. Therefore, BRAFV600E might be used as a biomarker when deciding future hormone therapies based on estrogen signaling in thyroid cancer patients.

Human Melanoma Cells Differentially Express RNASEL/RNase-L and miR-146a-5p under Sex Hormonal Stimulation

Polymorphisms in the ribonuclease L (RNASEL) coding gene and hsa-miR-146a-5p (miR-146a) have been associated with melanoma in a sex-specific manner. We hypothesized that RNASEL and miR-146a expression could be influenced by sex hormones playing a role in the female advantages observed in melanoma incidence and survival. Thus, we explored the effects of testosterone and 17β-estradiol on RNASEL and miR-146a expression in LM-20 and A375 melanoma cell lines. Direct targeting of miR-146a to the 3′ untranslated region (3′UTR) of RNASEL was examined using a luciferase reporter system. Our results indicate that RNASEL is a direct target of miR-146a in both melanoma cell lines. Trough qPCR and western blot analyses, we explored the effect of miR-146a mimic transfection in the presence of each hormone either on RNASEL mRNA level or on protein expression of RNase-L, the enzyme codified by RNASEL gene. In the presence of testosterone or 17β-estradiol, miR-146a overexpression did not influence RNASEL transcript level in LM-20 cell line, but it slightly induced RNASEL mRNA level in A375 cells. Remarkably, miR-146a overexpression was able to repress the protein level of RNase-L in both LM-20 and A375 cells in the presence of each hormone, as well as to elicit high expression levels of the activated form of the extracellular signal-regulated kinases (ERK)1/2, hence confirming the pro-tumorigenic role of miR-146a overexpression in melanoma. Thereafter, we assessed if the administration of each hormone could affect the endogenous expression of RNASEL and miR-146a genes in LM-20 and A375 cell lines. Testosterone exerted no significant effect on RNASEL gene expression in both cell lines, while 17β-estradiol enhanced RNASEL transcript level at least in LM-20 melanoma cells. Conversely, miR-146a transcript augmented only in the presence of testosterone in either melanoma cell line. Importantly, each hormone acted quite the opposite regarding the RNase-L protein expression, i.e., testosterone significantly decreased RNase-L expression, whereas 17β-estradiol increased it. Overall, the data show that, in melanoma cells treated with 17β-estradiol, RNase-L expression increased likely by transcriptional induction of its gene. Testosterone, instead, decreased RNase-L expression in melanoma cell lines with a post-transcriptional mechanism in which miR-146a could play a role. In conclusion, the pro-tumor activity of androgen hormone in melanoma cells could be exacerbated by both miR-146a increase and RNase-L downregulation. These events may contribute to the worse outcome in male melanoma patients.

Therapeutic Potential of Nitric Oxide‒Releasing Selective Estrogen Receptor Modulators in Malignant Melanoma

Malignant melanoma has a steadily increasing incidence, but treatment options are still limited, and the prognosis for patients, especially for men, is poor. To investigate whether targeting estrogen receptor (ER) signaling is a valid therapeutic approach, we retrospectively analyzed ER gene expression profiles in 448 patients with melanoma. High ERα gene (ESR1) expression was associated with improved overall survival (hazard ratio = 0.881; 95% confidence interval = 0.793-0.979; P = 0.018) and increased with tumor stage, whereas ERβ gene (ESR2) expression did not change with tumor progression. This seemingly protective function of ERα led us to speculate that specific targeting of ERβ has a therapeutic benefit in malignant melanoma. An ERβ-selective ER modulator with nitric oxide‒releasing moiety (nitric oxide‒releasing selective ER modulator 4d [NO-SERM 4d]) significantly reduced the prometastatic behavior of two melanoma cell lines (A2058 and MEL-JUSO). Epithelial‒mesenchymal transition in melanoma is consistent with a switch from E- to N-cadherin expression, mediating the invasive phenotype. NO-SERM 4d reduced N-cadherin expression and impaired spheroid formation in A2058 cells. In addition, the growth of A2058 spheroids was significantly reduced, confirming the antitumorigenic potential of NO-SERM 4d. Targeting ERβ signaling combined with targeted nitric oxide release represents a promising therapeutic approach in malignant melanoma that has the potential to prevent metastatic spread and reduce tumor growth.

Androgen receptor blockade promotes response to BRAF/MEK-targeted therapy

Treatment with therapy targeting BRAF and MEK (BRAF/MEK) has revolutionized care in melanoma and other cancers; however, therapeutic resistance is common and innovative treatment strategies are needed^1,2. Here we studied a group of patients with melanoma who were treated with neoadjuvant BRAF/MEK-targeted therapy ( NCT02231775 , n = 51) and observed significantly higher rates of major pathological response (MPR; ≤10% viable tumour at resection) and improved recurrence-free survival (RFS) in female versus male patients (MPR, 66% versus 14%, P = 0.001; RFS, 64% versus 32% at 2 years, P = 0.021). The findings were validated in several additional cohorts^2-4 of patients with unresectable metastatic melanoma who were treated with BRAF- and/or MEK-targeted therapy (n = 664 patients in total), demonstrating improved progression-free survival and overall survival in female versus male patients in several of these studies. Studies in preclinical models demonstrated significantly impaired anti-tumour activity in male versus female mice after BRAF/MEK-targeted therapy (P = 0.006), with significantly higher expression of the androgen receptor in tumours of male and female BRAF/MEK-treated mice versus the control (P = 0.0006 and P = 0.0025). Pharmacological inhibition of androgen receptor signalling improved responses to BRAF/MEK-targeted therapy in male and female mice (P = 0.018 and P = 0.003), whereas induction of androgen receptor signalling (through testosterone administration) was associated with a significantly impaired response to BRAF/MEK-targeted therapy in male and female patients (P = 0.021 and P < 0.0001). Together, these results have important implications for therapy.

Diarylpropionitrile inhibits melanogenesis via protein kinase A/cAMP-response element-binding protein/microphthalmia-associated transcription factor signaling pathway in α-MSH-stimulated B16F10 melanoma cells

Diarylpropionitrile (DPN), a selective agonist for estrogen receptor β (ERβ), has been reported to regulate various hormonal responses through activation of ERβ in tissues including the mammary gland and brain. However, the effect of DPN on melanogenesis independent of ERβ has not been studied. The aim of this study is to examine the possibility of anti-melanogenic effect of DPN and its underlying mechanism. Melanin contents and cellular tyrosinase activity assay indicated that DPN inhibited melanin biosynthesis in alpha-melanocyte stimulating hormone-stimulated B16F10 melanoma cell line. However, DPN had no direct influence on in vitro tyrosinase catalytic activity. On the other hand, 17β-estradiol had no effect on inhibition of melanogenesis, suggesting that the DPN-mediated suppression of melanin production was not related with estrogen signaling pathway. Immunoblotting analysis showed that DPN down-regulated the expression of microphthalmia-associated transcription factor (MITF), a central transcription factor of melanogenesis and its down-stream genes including tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2. Also, DPN attenuated the phosphorylation of protein kinase A (PKA) and cAMP-response element-binding protein (CREB). Additionally, DPN suppressed the melanin synthesis in UVB-irradiated HaCaT conditioned media culture system suggesting that DPN has potential as an anti-melanogenic activity in physiological conditions. Collectively, our data show that DPN inhibits melanogenesis via down-regulation of PKA/CREB/MITF signaling pathway.

Employing CRISPR-Cas9 to Generate CD133 Synthetic Lethal Melanoma Stem Cells

Malignant melanoma is a lethal skin cancer containing melanoma-initiating cells (MIC) implicated in tumorigenesis, invasion, and drug resistance, and is characterized by the elevated expression of stem cell markers, including CD133. The siRNA knockdown of CD133 enhances apoptosis induced by the MEK inhibitor trametinib in melanoma cells. This study investigates the underlying mechanisms of CD133's anti-apoptotic activity in patient-derived BAKP and POT cells, harboring difficult-to-treat NRASQ61K and NRASQ61R drivers, after CRISPR-Cas9 CD133 knockout or Dox-inducible expression of CD133. MACS-sorted CD133(+) BAKP cells were conditionally reprogrammed to derive BAKR cells with sustained CD133 expression and MIC features. Compared to BAKP, CD133(+) BAKR exhibit increased cell survival and reduced apoptosis in response to trametinib or the chemotherapeutic dacarbazine (DTIC). CRISPR-Cas9-mediated CD133 knockout in BAKR cells (BAKR-KO) re-sensitized cells to trametinib. CD133 knockout in BAKP and POT cells increased trametinib-induced apoptosis by reducing anti-apoptotic BCL-xL, p-AKT, and p-BAD and increasing pro-apoptotic BAX. Conversely, Dox-induced CD133 expression diminished apoptosis in both trametinib-treated cell lines, coincident with elevated p-AKT, p-BAD, BCL-2, and BCL-xL and decreased activation of BAX and caspases-3 and -9. AKT1/2 siRNA knockdown or inhibition of BCL-2 family members with navitoclax (ABT-263) in BAKP-KO cells further enhanced caspase-mediated apoptotic PARP cleavage. CD133 may therefore activate a survival pathway where (1) increased AKT phosphorylation and activation induces (2) BAD phosphorylation and inactivation, (3) decreases BAX activation, and (4) reduces caspases-3 and -9 activity and caspase-mediated PARP cleavage, leading to apoptosis suppression and drug resistance in melanoma. Targeting nodes of the CD133, AKT, or BCL-2 survival pathways with trametinib highlights the potential for combination therapies for NRAS-mutant melanoma stem cells for the development of more effective treatments for patients with high-risk melanoma.

Role of estrogen receptors in health and disease

Estrogen receptors (ERs) regulate multiple complex physiological processes in humans. Abnormal ER signaling may result in various disorders, including reproductive system-related disorders (endometriosis, and breast, ovarian, and prostate cancer), bone-related abnormalities, lung cancer, cardiovascular disease, gastrointestinal disease, urogenital tract disease, neurodegenerative disorders, and cutaneous melanoma. ER alpha (ERα), ER beta (ERβ), and novel G-protein-coupled estrogen receptor 1 (GPER1) have been identified as the most prominent ERs. This review provides an overview of ERα, ERβ, and GPER1, as well as their functions in health and disease. Furthermore, the potential clinical applications and challenges are discussed.

Endoxifen, an Estrogen Receptor Targeted Therapy: From Bench to Bedside

The selective estrogen receptor (ER) modulator, tamoxifen, is the only endocrine agent with approvals for both the prevention and treatment of premenopausal and postmenopausal estrogen-receptor positive breast cancer as well as for the treatment of male breast cancer. Endoxifen, a secondary metabolite resulting from CYP2D6-dependent biotransformation of the primary tamoxifen metabolite, N-desmethyltamoxifen (NDT), is a more potent antiestrogen than either NDT or the parent drug, tamoxifen. However, endoxifen's antitumor effects may be related to additional molecular mechanisms of action, apart from its effects on ER. In phase 1/2 clinical studies, the efficacy of Z-endoxifen, the active isomer of endoxifen, was evaluated in patients with endocrine-refractory metastatic breast cancer as well as in patients with gynecologic, desmoid, and hormone-receptor positive solid tumors, and demonstrated substantial oral bioavailability and promising antitumor activity. Apart from its potent anticancer effects, Z-endoxifen appears to result in similar or even greater bone agonistic effects while resulting in little or no endometrial proliferative effects compared with tamoxifen. In this review, we summarize the preclinical and clinical studies evaluating endoxifen in the context of breast and other solid tumors, the potential benefits of endoxifen in bone, as well as its emerging role as an antimanic agent in bipolar disorder. In total, the summarized body of literature provides compelling arguments for the ongoing development of Z-endoxifen as a novel drug for multiple indications.

Association Between Sex and Immune Checkpoint Inhibitor Outcomes for Patients With Melanoma

IMPORTANCE

Immune checkpoint inhibitors (ICIs) have revolutionized melanoma treatment and are now standard of care. Although sex is associated with immune function and immune-related diseases, the interaction between sex and ICIs is understudied.

OBJECTIVE

To examine whether cancer immunotherapy effectiveness varies between female and male patients with advanced melanoma treated with either nivolumab plus ipilimumab combination therapy or anti-programmed cell death protein 1 (PD-1) therapy (namely, pembrolizumab or nivolumab).

DESIGN, SETTING, AND PARTICIPANTS

The study population consisted of 1369 older adults (aged ≥65 years) with a record of melanoma diagnosis from January 1, 1991, to December 31, 2015, in the Surveillance, Epidemiology, and End Results-Medicare linked database. Patients with a diagnosis of stage III or stage IV melanoma and a claims record showing nivolumab plus ipilimumab combination therapy or anti-PD-1 therapy (ie, pembrolizumab or nivolumab) as their last type of ICI prescribed were included in the analyses. Patients were followed up through December 31, 2017, for the overall survival analysis. Statistical analysis was performed from September 19, 2019, to February 20, 2021.

EXPOSURES

Sex, last prescribed ICI, and prior use of ipilimumab.

MAIN OUTCOMES AND MEASURES

The primary outcome was overall survival, defined as time from the index date until death from any cause, with patients censored at the end of the study (December 31, 2017). Cox proportional hazards regression modeling was used to examine the association of sex with ICI outcomes while adjusting for prior use of ipilimumab, age at ICI initiation, Charlson Comorbidity Index, cancer stage at the time of diagnosis, and autoimmune disease diagnosis.

RESULTS

Among the 1369 patients in the study (982 men [71.7%]; median age, 75 years [IQR, 69-82 years]), the outcome of nivolumab plus ipilimumab combination therapy depended on sex (Wald χ2 = 9.48; P = .009 for interaction). The mortality hazard ratio (HR) for women with prior ipilimumab use receiving combination therapy was 2.06 times (95% CI, 1.28-3.32; P = .003) higher than their male counterparts. No significant difference was observed between women and men receiving anti-PD-1 therapy with (HR, 0.97 [95% CI, 0.68-1.38]; P = .85) or without prior ipilimumab use (HR, 0.85 [95% CI, 0.67-1.07]; P = .16). For women with prior ipilimumab use, combination therapy was associated with 2.82 times higher mortality hazards than anti-PD-1 therapy (95% CI, 1.73-4.60). No statistically significant difference was seen in mortality risk between anti-PD-1 therapy and combination therapy for men.

CONCLUSIONS AND RELEVANCE

This cohort study suggests that female patients with advanced melanoma may not benefit as much from combination ICIs as male patients would. Tumor mutation burden or estrogen level may serve as an important biomarker associated with ICI response in metastatic melanoma.

Inhibition of estrogen signaling in myeloid cells increases tumor immunity in melanoma

Immune checkpoint blockade (ICB) therapies have significantly prolonged patient survival across multiple tumor types, particularly in melanoma. Interestingly, sex-specific differences in response to ICB have been observed, with males receiving a greater benefit from ICB than females, although the mechanism or mechanisms underlying this difference are unknown. Mining published transcriptomic data sets, we determined that the response to ICBs is influenced by the functionality of intratumoral macrophages. This puts into context our observation that estrogens (E2) working through the estrogen receptor α (ERα) stimulated melanoma growth in murine models by skewing macrophage polarization toward an immune-suppressive state that promoted CD8+ T cell dysfunction and exhaustion and ICB resistance. This activity was not evident in mice harboring macrophage-specific depletion of ERα, confirming a direct role for estrogen signaling within myeloid cells in establishing an immunosuppressed state. Inhibition of ERα using fulvestrant, a selective estrogen receptor downregulator (SERD), decreased tumor growth, stimulated adaptive immunity, and increased the antitumor efficacy of ICBs. Further, a gene signature that determines ER activity in macrophages predicted survival in patients with melanoma treated with ICB. These results highlight the importance of E2/ER signaling as a regulator of intratumoral macrophage polarization, an activity that can be therapeutically targeted to reverse immune suppression and increase ICB efficacy.

Sex-Based Differences in Treatment with Immune Checkpoint Inhibition and Targeted Therapy for Advanced Melanoma: A Nationwide Cohort Study

Simple Summary

Melanoma is a malignant form of skin cancer. The overall survival of patients with advanced stages of disease were initially low. Fortunately, in recent years systemic treatment with immunotherapy has prolonged survival. We set out to answer the question whether men and women with advanced melanoma differ in prognostic factors, tumor-response to immunotherapy, and treatment-related adverse events. All patients in the Netherlands were registered between July 2013 and July 2018. We showed that although clinical and tumor characteristics differ, the safety profile of immunotherapy is comparable. Furthermore, overall, a 10% survival advantage for women was seen. Following immunotherapy there was no survival difference.

Abstract

Recent meta-analyses show conflicting data on sex-dependent benefit following systemic treatment for advanced melanoma patients. We examined the nationwide Dutch Melanoma Treatment Registry (July 2013–July 2018), assessing sex-dependent differences in advanced melanoma patients (stage IIIC/IV) with respect to clinical characteristics, mutational profiles, treatments initiated, grade 3–4 adverse events (AEs), treatment responses, and mortality. We included 3985 patients, 2363 men (59%) and showed that although men and women with advanced melanoma differ in clinical and tumor characteristics, the safety profile of immune checkpoint inhibition (ICI) is comparable. The data suggest a 10% survival advantage for women, mainly seen in patients ≥60 years of age and patients with BRAF V600 mutant melanoma. Following ICI there was no survival difference.

The Sex-Related Interplay between TME and Cancer: On the Critical Role of Estrogen, MicroRNAs and Autophagy

The interplay between cancer cells and the tumor microenvironment (TME) has a fundamental role in tumor progression and response to therapy. The plethora of components constituting the TME, such as stroma, fibroblasts, endothelial and immune cells, as well as macromolecules, e.g., hormones and cytokines, and epigenetic factors, such as microRNAs, can modulate the survival or death of cancer cells. Actually, the TME can stimulate the genetically regulated programs that the cell puts in place under stress: apoptosis or, of interest here, autophagy. However, the implication of autophagy in tumor growth appears still undefined. Autophagy mainly represents a cyto-protective mechanism that allows cell survival but, in certain circumstances, also leads to the blocking of cell cycle progression, possibly leading to cell death. Since significant sex/gender differences in the incidence, progression and response to cancer therapy have been widely described in the literature, in this review, we analyzed the roles played by key components of the TME, e.g., estrogen and microRNAs, on autophagy regulation from a sex/gender-based perspective. We focused our attention on four paradigmatic and different forms of cancers-colon cancer, melanoma, lymphoma, and lung cancer-concluding that sex-specific differences may exert a significant impact on TME/cancer interaction and, thus, tumor growth.

Inhibitory activity of acteoside in melanoma via regulation of the ERβ-Ras/Raf1-STAT3 pathway

BACKGROUND

Melanoma is an aggressive cancer with a rapidly increasing incidence rate worldwide. Acteoside has been shown to have antitumor effects in multiple human cancers; however, the underlying function and mechanisms of acteoside in melanoma remain unclear.

PURPOSE

This study explored the inhibitory effect of acteoside on melanoma and the possible mechanisms.

METHODS

Acteoside (15 mg/kg, 30 mg/kg) was administered to mice daily for 21 days. ICI182,780 (0.5 mg/kg) was intraperitoneally injected 30 min before acteoside administration three times a week to evaluate whether the effects elicited by acteoside were mediated via the estrogen receptor. Tumor growth and metabolism, cardiac function, ROS and apoptosis levels in the spleen, serum inflammatory factors, and immune cells in the spleen were monitored. STAT3, p-STAT3, CD31, and survivin levels in tumor tissues were measured via immunofluorescence. Ras, Raf1, STAT3, p-STAT3, Bcl-2, Bax, cleaved caspase-3, and cleaved caspase-9 levels in tumor tissues were determined via Western Blotting.

RESULTS

The results showed that acteoside inhibited melanoma growth, alleviated inflammation levels in mice, attenuated ROS and apoptosis levels in the spleen, downregulated the levels of CD31, survivin, Ras, Raf1, p-STAT3, and Bcl-2, and upregulated the levels of ERβ, Bax, cleaved caspase-3, and cleaved caspase-9. Moreover, the effect of acteoside was blocked by ICI182,780.

CONCLUSION

Acteoside may promote the apoptosis of tumor cells by regulating the ERβ-Ras/Raf1-STAT3 signaling axis, thus inhibiting the occurrence and development of melanoma.

Current Perspectives and Novel Strategies of NRAS-Mutant Melanoma

Melanoma is the deadliest cutaneous cancer. Activating mutations in NRAS are found in 20% of melanomas. NRAS-mutant melanoma is more aggressive and, therefore, has poorer outcomes, compared to non-NRAS-mutant melanoma. Despite promising preclinical data, to date immune checkpoint inhibitors remain the standard of care for locally advanced unresectable or metastatic NRAS melanoma. Data for efficacy of immunotherapy for NRAS melanoma mainly come from retrospective cohorts with divergent conclusions. MEK inhibitors have been the most developed targeted therapy approach. Although associated with an increase in progression-free survival, MEK inhibitors do not provide any benefit in terms of overall survival. Combination strategies with PI3K-AKT-mTOR pathway and CDK4/6 inhibitors seem to increase MEK inhibitors' benefit. Nevertheless, results from clinical trials are still prelaminar. A greater comprehension of the biology and intracellular interactions of NRAS-mutant melanoma will outline novel impactful strategies which could improve prognosis of these subgroup of patients.

Sex disparity in skin carcinogenesis and potential influence of sex hormones

Background

Sex or gender disparity in skin cancer has been documented for a long time at the population level. UV radiation (UVR) is a common environmental risk for all three major types of skin cancer: cutaneous melanoma (CM), basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC). The underlying mechanism for sex disparity has been largely attributed to sex‐differentiated behaviour patterns related to UVR. Non‐UVR factors such as intrinsic physiological differences have been suggested but remain understudied.

Aims, Materials and Methods

This review summarizes and compares the known sex differences in three skin cancer types with regard to body site distribution and age influence.

Results

We found a similar age‐dependent sex difference pattern in CM and BCC. Specifically, CM and BCC tend to show higher incidence in young women and old men, with a switching age around menopause. The switching age suggests involvement of sex hormones, which has shown controversial influence on skin cancers at epidemiological level. Literatures regarding sex hormone receptors for oestrogen, androgen and progesterone are summarized for potential explanations at molecular level.

Discussion

Overall, more and more evidence suggests non‐UVR factors such as sex hormones play critical roles in skin cancer (especially CM and BCC), yet solid population and molecular evidence are required. Incidences of skin cancer are increasing which suggests limited effect for the current UVR‐avoidance prevention methods.

Conclusion

Fully understanding the causes of sex disparities in incidence is necessary for developing a comprehensive prevention strategy.

Association between melanoma and exposure to sex hormones in puberty: A possible window of susceptibility (Review)

The risk factors for melanoma in adolescents are similar to those in adults; however, it remains unclear whether these risk factors are also associated with melanoma in children. Epidemiological studies in the literature have reported a logarithmic increase in melanoma incidence after the age of 10 years. This may, in part, reflect the acute and chronic exposure to solar ultraviolet (UV) radiation during childhood. However, it appears unlikely that the cumulative exposure to UV radiation alone could explain such a sharp increase in melanoma incidence at the beginning of adolescence. It has been suggested that circulating sex hormones, the levels of which increase during puberty, may play a role in melanoma initiation and progression in predisposed individuals through binding to specific sex steroid receptors. The association between a longer cumulative exposure to sex hormones and the risk of melanoma may be supported by the reported epidemiological association between melanoma and several other sex hormone-related types of cancer, such as breast and prostate cancer, in which the enhanced exposure to androgens and estrogens was found to be directly associated with pubertal onset. Therefore, determining the association between pubertal onset and melanoma development may improve the current understanding of melanoma pathophysiology.

Sex Disparities in the Clinical Characteristics, Synchronous Distant Metastasis Occurrence and Prognosis: A Pan-cancer Analysis

Background: This study aims to assess the sex disparities in clinical characteristics and synchronous distant metastasis occurrence at diagnosis, as well as the subsequent prognosis in non-sex-specific cancers. Methods: The study included details from patients diagnosed with non-sex-specific cancers, during the period from 2010 to 2016, in the Surveillance, Epidemiology, and End Results (SEER) program. The distant metastasis prevalence and subsequent survival time were summarized in the total population and the population with specific cancers of different systems. The multivariable logistic and the Cox proportional hazards regressions were applied to evaluate the sex effect on distant metastasis occurrence and prognosis. The results were combined using meta-analysis. Results: Across all non-sex-specific cancers, the pooled prevalence of distant metastasis was 15.2% (95% CI: 14.7-15.7%) and 7.1% (95% CI: 6.8-7.3%) for males and females, respectively. The pooled median survival time was 8.40 months (95% CI: 7.99-8.81) for male patients and 9.40 months (95% CI: 8.84-10.02) for female patients. After combining all non-sex-specific cancers, male patients displayed a higher distant metastasis occurrence than females (pooled OR=1.06, 95% CI: 1.04-1.08; P<0.01), as well as worse overall survival after distant metastasis (pooled HR=1.08, 95% CI: 1.05-1.10; P<0.01). The sex differences were more significant in patients younger than 65 years (P<0.01). Additionally, the sex influence on prognosis was most predominant amongst patients from Asian or Pacific Islander ethnic groups. Conclusion: Male gender appears to be an independent risk factor associated with the occurrence and prognosis of synchronous distant metastasis. Therefore, sex-specific preventions and treatments should become the focus of future research.

Identification of suitable mRNAs and microRNAs as reference genes for expression analyses in skin cells under sex hormone exposure

Quantitative RT-PCR is the most accurate technique for the study of gene expression profiles, however, to ensure the accuracy of qPCR results, suitable reference genes are necessary for data normalization. Hormones influence the development and function of skin cells, regulating the expression of genes and miRNAs. Nevertheless, the stability of reference genes after sex hormone treatment has not been thoroughly investigated. In this study, we evaluated the expression of a set of candidate mRNAs and microRNsA (miRNA) as reference genes in keratinocytes (HaCaT cells), primary human fibroblasts and a melanoma cell line (LM-36 cells) under testosterone or 17β-estradiol treatment. Two algorithms, namely geNorm, Best-Keeper, and the comparative ΔCt method were used to evaluate the expression stability of the candidate reference genes. The comprehensive ranking showed that TBP and miR-191-5p are the most stable expressed genes across all cultured cells under hormone treatment. Furthermore, we observed that GAPDH, HPRT1 and U6 snRNA expression may be altered by hormone exposure, thus, these genes are not recommended as reference genes. In conclusion, the present study provides, to the best of our knowledge, the first evaluation of expressed mRNA(s) and miRNA(s) as reference genes in three different types of skin cells under the stimulation of sex hormones.

Identification of Signatures of Prognosis Prediction for Melanoma Using a Hypoxia Score

Melanoma is one of the most aggressive cancers. Hypoxic microenvironment affects multiple cellular pathways and contributes to tumor progression. The purpose of the research was to investigate the association between hypoxia and melanoma, and identify the prognostic value of hypoxia-related genes. Based on the GSVA algorithm, gene expression profile collected from The Cancer Genome Atlas (TCGA) was used for calculating the hypoxia score. The Kaplan–Meier plot suggested that a high hypoxia score was correlated with the inferior survival of melanoma patients. Using differential gene expression analysis and WGCNA, a total of 337 overlapping genes associated with hypoxia were determined. Protein-protein interaction network and functional enrichment analysis were conducted, and Lasso Cox regression was performed to establish the prognostic gene signature. Lasso regression showed that seven genes displayed the best features. A novel seven-gene signature (including ABCA12, PTK6, FERMT1, GSDMC, KRT2, CSTA, and SPRR2F) was constructed for prognosis prediction. The ROC curve inferred good performance in both the TCGA cohort and validation cohorts. Therefore, our study determined the prognostic implication of the hypoxia score in melanoma and showed a novel seven-gene signature to predict prognosis, which may provide insights into the prognosis evaluation and clinical decision making.

Ca2+ as a therapeutic target in cancer

Ca2+ is a ubiquitous and dynamic second messenger molecule that is induced by many factors including receptor activation, environmental factors, and voltage, leading to pleiotropic effects on cell function including changes in migration, metabolism and transcription. As such, it is not surprising that aberrant regulation of Ca2+ signals can lead to pathological phenotypes, including cancer progression. However, given the highly context-specific nature of Ca2+-dependent changes in cell function, delineation of its role in cancer has been a challenge. Herein, we discuss the distinct roles of Ca2+ signaling within and between each type of cancer, including consideration of the potential of therapeutic strategies targeting these signaling pathways.

Sex and Gender Disparities in Melanoma

Worldwide, the total incidence of cutaneous melanoma is higher in men than in women, with some differences related to ethnicity and age and, above all, sex and gender. Differences exist in respect to the anatomic localization of melanoma, in that it is more frequent on the trunk in men and on the lower limbs in women. A debated issue is if-and to what extent-melanoma development can be attributed to gender-specific behaviors or to biologically intrinsic differences. In the search for factors responsible for the divergences, a pivotal role of sex hormones has been observed, although conflicting results indicate the involvement of other mechanisms. The presence on the X chromosome of numerous miRNAs and coding genes playing immunological roles represents another important factor, whose relevance can be even increased by the incomplete X chromosome random inactivation. Considering the known advantages of the female immune system, a different cancer immune surveillance efficacy was suggested to explain some sex disparities. Indeed, the complexity of this picture emerged when the recently developed immunotherapies unexpectedly showed better improvements in men than in women. Altogether, these data support the necessity of further studies, which consider enrolling a balanced number of men and women in clinical trials to better understand the differences and obtain actual gender-equitable healthcare.

The variable association between expression and methylation of estrogen receptors and the survival of patients with different tumors

BACKGROUND

Estrogen receptor (ER) is essential in reproductive development and is also the primary driver of breast cancers. Deregulation of ER may also be involved in tumorigenesis of other organs. To understand the role of ER in different tumor types, pan-cancer analysis of estrogen receptor alpha (ESR1) and estrogen receptor beta (ESR2) in various tumors and association with patients' survival were conducted using The Cancer Genome Atlas (TCGA) data.

RESULTS

Gene methylation level was evaluated by the mean methylation level of CpG sites in the promoter region. The significant different DNA methylation between tumor and healthy tissues was shown in 10 tumor types for ESR1 and eight tumor types for ESR2. The methylation pattern was also varied across different TCGA tumors. The pan-cancer analysis showed significantly different mRNA expression of ESR1 in nine tumor types and ESR2 in four tumor types. Survival analysis showed that the effects of ERs expression on survival are diverse in different tumors. The expression of ERs was associated with tumor molecular subtypes and various clinical characteristics. ER correlated genes were mainly enriched in cancer and immune-related pathways.

CONCLUSIONS

Our pan-cancer analysis data indicated that ERs might be significantly associated with carcinogenesis and progression of some tumors, which may be potential therapeutic targets and prognosis biomarkers.

Sexual Dimorphism in Cellular and Molecular Features in Human ACTH-Secreting Pituitary Adenomas

(1) Background. Cushing's disease presents gender disparities in prevalence and clinical course. Little is known, however, about sexual dimorphism at the level of the corticotrope adenoma itself. The aim of the present study was to evaluate molecular features of ACTH-secreting pituitary adenomas collected from female and male patients with Cushing's disease. (2) Methods. We analyzed 153 ACTH-secreting adenomas collected from 31 men and 122 women. Adenomas were established in culture and ACTH synthesis and secretion assessed in basal conditions as well as during incubation with CRH or dexamethasone. Concurrently, microarray analysis was performed on formalin-fixed specimens and differences in the expression profiles between specimens from male and female patients identified. (3) Results. ACTH medium concentrations in adenomas obtained from male patients were significantly lower than those observed in adenomas from female patients. This could be observed for baseline as well as modulated secretion. Analysis of corticotrope transcriptomes revealed considerable similarities with few, selected differences in functional annotations. Differentially expressed genes comprised genes with known sexual dimorphism, genes involved in tumour development and genes relevant to pituitary pathophysiology. (4) Conclusions. Our study shows for the first time that human corticotrope adenomas present sexual dimorphism and underlines the need for a gender-dependent analysis of these tumours. Differentially expressed genes may represent the basis for gender-tailored target therapy.

Sex-Based Differences in Melanoma Survival in a Contemporary Patient Cohort

Background: A female survival advantage in cutaneous melanoma has been long recognized. However, whether this extends across all age groups, with risk stratification using the latest prognostic staging system or in the current era of efficacious systemic therapies is unknown. Therefore, we evaluated whether sex-based differences in melanoma survival persisted within a recent population-based patient cohort with consideration of these factors. Materials and Methods: We identified stage II-IV cutaneous melanoma patients from 2010 to 2014 Surveillance, Epidemiology, and End Results cancer registries data. We recalculated stage per American Joint Committee on Cancer 8th edition guidelines. Cancer-specific survival (CSS) was estimated by using the Kaplan-Meier method and multivariable Cox proportional hazards regression. Results: Of 16,807 patients (39.8% female), 8,990 were stage II, 4,826 stage III, and 2,991 stage IV at diagnosis. Unadjusted 3-/5-year CSS estimates for females versus males were 64.2% versus 59.7%, and 53.5% versus 49.9%, respectively, p ≤ 0.0001. Five-year CSS varied within each stage and across age strata of <45, 45 - 59, and ≥60 years. Within each stage, females <45 had better CSS than all other sex/age groups (p < 0.0001). In multivariable analysis of stage II/III patients, female sex, younger age, and lower mitotic index retained favorable CSS prognostic significance (p < 0.001). Conclusions: Sex-based differences in melanoma survival persist in a contemporary patient cohort staged with the latest prognostic system. These data may guide decision marking regarding adjuvant therapy, highlight the importance of including sex as a pre-specified clinical trial variable, and suggest that investigation of underlying biologic mechanisms may drive discovery of biomarkers and therapeutic targets to improve patient care.

Gender Differences and Outcomes in Melanoma Patients

INTRODUCTION

Melanoma is one of the most common cancers in younger people. The incidence of cutaneous melanoma is increasing in patients of both sexes, with female patients generally living longer than their male counterparts. The aim of this retrospective study was to evaluate and confirm the sex-based difference in survival of melanoma patients and the relationship of this difference with pathological features.

METHODS

A total of 1023 patients who had been treated at the Department of Medical Oncology, Università Politecnica Marche (Ancona, Italy) and the INRCA-IRCCS Department of Dermatology (Ancona, Italy) between 1987 and 2014 were enrolled in the study.

RESULTS

In terms of stage of disease at onset, there was a significant difference in disease-free survival (DFS) and overall survival (OS) in favor of female patients in disease stage I (P  = 0.001 and P  = 0.01, respectively) and II (P  = 0.02 and P  = 0.009, respectively). Female patients also showed a significant improvement in 12-year DFS and 12-year OS adjusted for pathological features (Breslow thickness, ulceration, "absent" tumor-infiltrating lymphocyte (TIL) melanomas, "non-brisk" TIL pattern). Globally, female patients had an advantage over with male patients in both DFS and OS (P  < 0.001).

CONCLUSIONS

Our results show that women have a survival benefit over with men after adjustment for many variables that can reduce mortality risk in female melanoma patients. In a future investigation we wish to examine possible biological sex differences in tumor-host interactions.

Hormone replacement therapy and the risk of melanoma in post-menopausal women

STUDY QUESTION

Is hormone replacement therapy (HRT) associated with an increased risk of melanoma skin cancer or prognostic outcomes amongst post-menopausal women?

SUMMARY ANSWER

Whilst we found evidence of an association with melanoma risk, the lack of dose-response and associations observed with recent use, localised disease and intravaginal oestrogens suggests this is a non-causal association.

WHAT IS KNOWN ALREADY

Evidence on HRT and melanoma risk remains inconclusive, with studies providing conflicting results. Furthermore, evidence on melanoma survival is sparse, with only one previous study reporting protective associations with HRT use, likely attributable to immortal time bias.

STUDY DESIGN, SIZE, DURATION

We conducted a nation-wide population-based case-control study and a retrospective cohort study utilising the Danish healthcare registries. Case-control analyses included 8279 women aged 45-85 with a first-ever diagnosis of malignant melanoma between 2000 and 2015, matched by age and calendar time to 165 580 population controls. A cohort of 6575 patients with a diagnosis of primary malignant melanoma between 2000 and 2013 and followed through 2015 was examined to determine if HRT use had an impact on melanoma survival outcomes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Based on prescriptions dispensed since 1995, ever-use of HRT was defined as having filled at least one prescription for HRT prior to the index date. In total, 2629 cases (31.8%) and 47 026 controls (28.4%) used HRT. Conditional logistic regression was used to calculate odds ratios (ORs) for melanoma risk according to HRT use, compared with non-use, adjusting for potential confounders. For cohort analyses, Cox proportional hazards models was used to estimate adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for second melanoma incidence and all-cause mortality associated with HRT.

MAIN RESULTS AND THE ROLE OF CHANCE

High use of HRT was associated with an OR of 1.21 (95% CI 1.13-1.29) for melanoma risk, with no evidence of a dose-response pattern. Results were most pronounced amongst recent high users (OR, 1.28; 95% CI 1.17-1.41), for localised disease (OR, 1.25; 95% CI 1.15-1.36) and for intravaginal oestrogen therapy (OR, 1.38; 95% CI 1.13-1.68). Compared with non-use, there was no evidence of an association for secondary melanoma for post-diagnostic new-use (fully adjusted HR, 1.56; 95% CI 0.64-3.80) or continuous HRT use (fully adjusted HR, 1.26; 95% CI 0.89-1.78). Similar associations were observed for all-cause mortality.

LIMITATIONS, REASONS FOR CAUTION

Despite the large sample size and the use of robust population-based registries with almost complete coverage, we lacked information on some important confounders including sun exposure.

WIDER IMPLICATIONS OF THE FINDINGS

Whilst we cannot rule out an association between HRT use and melanoma risk, the associations observed are also compatible with increased healthcare utilisation and thus increased melanoma detection amongst HRT users. No association between HRT use and melanoma survival outcomes was observed. This should provide some reassurance to patients and clinicians, particularly concerning the use of HRT in patients with a history of melanoma.

STUDY FUNDING/COMPETING INTEREST(S)

B.M.H. is funded by a Cancer Research UK Population Research Postdoctoral Fellowship. The funding source had no influence on the design or conduct of this study. A.P. reports participation in research projects funded by Alcon, Almirall, Astellas, Astra-Zeneca, Boehringer-Ingelheim, Servier, Novo Nordisk and LEO Pharma, all with funds paid to the institution where he was employed (no personal fees) and with no relation to the work reported in this article. The other authors have no competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

Estrogen Receptors and Melanoma: A Review

In the last three decades cutaneous melanoma has been widely investigated as a steroid hormone-sensitive cancer. Following this hypothesis, many epidemiological studies have investigated the relationship between estrogens and melanoma. No evidence to date has supported this association due to the great complexity of genetic, external and environmental factors underlying the development of this cancer. Molecular mechanisms through which estrogen and their receptor exert a role in melanoma genesis are still under investigation with new studies increasingly focusing on the discovery of new molecular targets for therapeutic treatments.

Menopausal Hormone Therapy and Risk of Melanoma: A Nationwide Register-Based Study in Finland

BACKGROUND

The association between use of menopausal hormone therapy and risk of cutaneous melanoma is highly debated. We investigated the issue in a Finnish nationwide cohort of women ages 50 years or older.

METHODS

All women who had purchased hormone therapy between 1994 and 2007 were identified from the national Medical Reimbursement Registry and linked to the Finnish Cancer Registry. We calculated standardized incidence ratios (SIR) to compare incidence of cutaneous melanoma among hormone therapy users with that of the general population.

RESULTS

During a mean follow-up of 15.6 years, 1,695 incident cutaneous melanoma cases were identified among 293,570 women who had used hormone therapy for at least 6 months. The SIRs for women who used unopposed estrogen therapy and combined estrogen-progestin therapy (EPT) for 6 to 59 months were 1.20 [95% confidence interval (CI), 1.06-1.35] and 1.00 (95% CI, 0.87-1.14; P heterogeneity = 0.04). The SIRs for women who used estrogen therapy and EPT for at least 60 months were 1.37 (95% CI, 1.22-1.52) and 1.23 (95% CI, 1.13-1.34; P heterogeneity = 0.15). We did not find significant differences between oral and transdermal administrations, nor between doses of estrogens.

CONCLUSIONS

Use of hormone therapy, especially estrogen therapy, was associated with an increased risk of cutaneous melanoma. EPT use of less than 5 years was not associated with an increased risk of cutaneous melanoma.

IMPACT

Our results add to the growing body of epidemiologic evidence that the use of unopposed estrogens in menopause increases the risk of cutaneous melanoma, while the addition of progestins might counteract the detrimental effect.

Cyanidin-3-o-Glucoside Pharmacologically Inhibits Tumorigenesis via Estrogen Receptor β in Melanoma Mice

Expression patterns of estrogen receptors [ERα, ERβ, and G-protein associated ER (GPER)] in melanoma and skin may suggest their differential roles in carcinogenesis. Phytoestrogenic compound cyanidin-3-o-glucoside (C3G) has been shown to inhibit the growth and metastatic potential of melanoma, although the underlying molecular mechanism remains unclear. The aim of this study was to clarify the mechanism of action of C3G in melanoma in vitro and in vivo, as well as to characterize the functional expressions of ERs in melanoma. In normal skin or melanoma (n = 20/each), no ERα protein was detectable, whereas expression of ERβ was high in skin but weak focal or negative in melanoma; and finally high expression of GPER in all skin vs. 50% melanoma tissues (10/20) was found. These results correspond with our analysis of the melanoma survival rates (SRs) from Human Protein Atlas and The Cancer Genome Atlas GDC (362 patients), where low ERβ expression in melanoma correlate with a poor relapse-free survival, and no correlations were observed between SRs and ERα or GPER expression in melanoma. Furthermore, we demonstrated that C3G treatment arrested the cell cycle at the G2/M phase by targeting cyclin B1 (CCNB1) and promoted apoptosis via ERβ in both mouse and human melanoma cell lines, and inhibited melanoma cell growth in vivo. Our study suggested that C3G elicits an agonistic effect toward ERβ signaling enhancement, which may serve as a potential novel therapeutic and preventive approach for melanoma.

Hormone Replacement Therapy in Cancer Survivors - Review of the Literature

Rapid advance in oncology leads to increasing survival of oncologic patients. More and more of them live long enough to reach either the natural age of menopause or, as a side effect of their oncotherapy, experience the cessation of gonadal function, leading to premature ovarian insufficiency, with disturbing vasomotor symtoms and long-term negative cardiovascular and skeletal effects. Thus, an ever increasing number of cancer survivors search endocrinologic help in the form of hormone replacement therapy (HRT). The misinterpretation of the WHI (Women's Health Initiative) Study has lead to an irrational fear of female hormone replacement, both by the general population and medical professionals. It has seemed the logical and safe conclusion to many physicians to avoid HRT, supposing that this attitude definitely causes no harm, whereas the decision of prescribing estrogen alone or with progestins might bear oncologic and thromboembolic risks and may even lead to litigation in case of a potentially related complication. However, it was known even before the WHI results that premature menopause and hypogonadism decreases the life expectancy of women by years through its skeletal and cardiovascular effects, and this negative effect correlates with the length of the hypoestrogenaemic period. Therefore, the denial of HRT also needs to be supported by evidence and should be weighed againts the risks of HRT. Yet, the oncologic risk of HRT is extremely difficult to assess. In this work we review the latest evidence from in vitro experiments to clinical studies, regarding HRT in survivors of gynecologic and non-gynecologic cancers. Based on our literature research, we group tumours regarding the oncologic risk of properly chosen female hormone replacement therapy in cancer survivors as follows: ’HRT is advanageous’ (e.g. endometrial cancer type I, cervical adenocarcinoma, haematologic malignancies, local cutaneous malignant melanoma, colorectal cancer, hepatocellular cancer); ’HRT is neutral’ (e.g. BRCA 1/2 mutation carriers without cancer, endometrial cancer type II, uterinal carcinosarcoma and adenosarcoma, certain types of ovarian cancer, cervical, vaginal and vulvar squamous cell carcinoma, prolactinoma, kidney cancer, pancreatic cancer, thyroid cancer); ’HRT is relatively contraindicated’ for various reasons (e.g. leiomyosarcoma, certain types of ovarian tumours, brain tumours, advanced metastatic malignant melanoma, lung cancer, gastric cancer, bladder cancer); ’HRT is diasadvantageous and thus contraindicated’ (e.g. breast cancer, endometrial stroma sarcoma, meningioma, glioma, hormone receptor positive gastric and bladder cancer).

Ethinylestradiol and Levonorgestrel as Active Agents in Normal Skin, and Pathological Conditions Induced by UVB Exposure: In Vitro and In Ovo Assessments

The link between melanoma development and the use of oral combined contraceptives is not fully elucidated, and the data concerning this issue are scarce and controversial. In the present study, we show that the components of oral contraceptives, ethinylestradiol (EE), levonorgestrel (LNG), and their combination (EE + LNG) ± UVB (ultraviolet B radiation) induced differential effects on healthy (human keratinocytes, fibroblasts, and primary epidermal melanocytes, and murine epidermis cells) and melanoma cells (human—A375 and murine—B164A5), as follows: (i) at low doses (1 µM), the hormones were devoid of significant toxicity on healthy cells, but in melanoma cells, they triggered cell death via apoptosis; (ii) higher doses (10 µM) were associated with cytotoxicity in all cells, the most affected being the melanoma cells; (iii) UVB irradiation proved to be toxic for all types of cells; (iv) UVB irradiation + hormonal stimulation led to a synergistic cytotoxicity in the case of human melanoma cells—A375 and improved viability rates of healthy and B164A5 cells. A weak irritant potential exerted by EE and EE + LNG (10 µM) was assessed by the means of a chick chorioallantoic membrane assay. Further studies are required to elucidate the hormones’ cell type-dependent antimelanoma effect and the role played by melanin in this context.

Estrogen Regulation of T-Cell Function and Its Impact on the Tumor Microenvironment

Epidemiologic studies demonstrate significant gender-specific differences in immune system function. Males are more prone to infection and malignancies, while females are more vulnerable to autoimmune diseases. These differences are thought to be due to the action of gonadal hormones: Estrogen increases the inflammatory response and testosterone dampens it. More specifically, estrogen stimulation induces inflammatory cytokine production including interferon γ, interleukin (IL) 6, and tumor necrosis factor α, while testosterone induces IL-10, IL-4, and transforming growth factor β. More recent studies demonstrate threshold effects of estrogen stimulation on immune cell function: physiologic doses of estrogen (approximately 0.5 nmol/L) stimulate inflammatory cytokine production, but superphysiologic dosages (above 50 nmol/L) can result in decreased inflammatory cytokine production. This review reports findings concerning the impact of estrogen on CD8+ cytotoxic T cells and the overall immune response in the tumor microenvironment. Variables examined include dosage of hormone, the diversity of immune cells involved, and the nature of the immune response in cancer. Collective review of these points may assist in future hypotheses and studies to determine sex-specific differences in immune responses that may be used as targets in disease prevention and treatment.

A Potential Therapy Using Engineered Stem Cells Prevented Malignant Melanoma in Cellular and Xenograft Mouse Models

PURPOSE

In the present study, human neural stem cells (hNSCs) with tumor-tropic behavior were used as drug delivery vehicle to selectively target melanoma. A hNSC line (HB1.F3) was transduced into two types: one expressed only the cytosine deaminase (CD) gene (HB1.F3. CD) and the other expressed both CD and human interferon-β (IFN-β) genes (HB1.F3.CD. IFN-β).

Materials and Methods

This study verified the tumor-tropic migratory competence of engineered hNSCs on melanoma (A375SM) using a modified Boyden chamber assay in vitro and CM-DiI staining in vivo. The antitumor effect of HB1.F3.CD and HB1.F3.CD.IFN-β on melanoma was also confirmed using an MTT assay in vitro and xenograft mouse models.

RESULTS

A secreted form of IFN-β from the HB1.F3.CD.IFN-β cells modified the epithelial-mesenchymal transition (EMT) process and metastasis of melanoma. 5-Fluorouracil treatment also accelerated the expression of the pro-apoptotic protein BAX and decelerated the expression of the anti-apoptotic protein Bcl-xL on melanoma cell line.

CONCLUSION

Our results illustrate that engineered hNSCs prevented malignant melanoma cells from proliferating in the presence of the prodrug, and the form that secreted IFN-β intervened in the EMT process and melanoma metastasis. Hence, neural stem cell-directed enzyme/prodrug therapy is a plausible treatment for malignant melanoma.

Sea turtle fibropapilloma tumors share genomic drivers and therapeutic vulnerabilities with human cancers

Wildlife populations are under intense anthropogenic pressures, with the geographic range of many species shrinking, dramatic reductions in population numbers and undisturbed habitats, and biodiversity loss. It is postulated that we are in the midst of a sixth (Anthropocene) mass extinction event, the first to be induced by human activity. Further, threatening vulnerable species is the increased rate of emerging diseases, another consequence of anthropogenic activities. Innovative approaches are required to help maintain healthy populations until the chronic underlying causes of these issues can be addressed. Fibropapillomatosis in sea turtles is one such wildlife disease. Here, we applied precision-medicine-based approaches to profile fibropapillomatosis tumors to better understand their biology, identify novel therapeutics, and gain insights into viral and environmental triggers for fibropapillomatosis. We show that fibropapillomatosis tumors share genetic vulnerabilities with human cancer types, revealing that they are amenable to treatment with human anti-cancer therapeutics.

David Duffy et al. use a precision-medicine-based approach to study fibropapillomatosis tumors in sea turtles to identify environmental triggers and potential therapeutics. They show that these tumors share genetic similarities with human cancer types, and may be treatable using human anti-cancer therapies.

Genetic variants in RORA and DNMT1 associated with cutaneous melanoma survival

Cutaneous melanoma (CM) is considered as a steroid hormone-related malignancy. However, few studies have evaluated the roles of genetic variants encoding steroid hormone receptor genes and their related regulators (SHR-related genes) in CM-specific survival (CMSS). Here, we performed a pathway-based analysis to evaluate genetic variants of 191 SHR-related genes in 858 CMSS patients using a dataset from a genome-wide association study (GWAS) from The University of Texas MD Anderson Cancer Center (MDACC), and then validated the results in an additional dataset of 409 patients from the Harvard GWAS. Using multivariate Cox proportional hazards regression analysis, we identified three-independent SNPs (RORA rs782917 G > A, RORA rs17204952 C > T and DNMT1 rs7253062 G > A) as predictors of CMSS, with a variant-allele attributed hazards ratio (HR) and 95% confidence interval of 1.62 (1.25-2.09), 1.60 (1.20-2.13) and 1.52 (1.20-1.94), respectively. Combined analysis of risk genotypes of these three SNPs revealed a decreased CMSS in a dose-response manner as the number of risk genotypes increased (ptrend  < 0.001); however, no improvement in the prediction model was observed (area under the curve [AUC] = 79.6-80.8%, p = 0.656), when these risk genotypes were added to the model containing clinical variables. Our findings suggest that genetic variants of RORA and DNMT1 may be promising biomarkers for CMSS, but these results needed to be validated in future larger studies.

Estrogen Receptor (ER) Subtype Selectivity Identifies 8-Prenylapigenin as an ERβ Agonist from Glycyrrhiza inflata and Highlights the Importance of Chemical and Biological Authentication

Postmenopausal women are increasingly using botanicals for menopausal symptom relief due to the increased breast cancer risk associated with traditional estrogen therapy. The deleterious effects of estrogens are associated with estrogen receptor (ER)α-dependent proliferation, while ERβ activation could enhance safety by opposing ERα effects. Three medicinal licorice species, Glycyrrhiza glabra ( G. glabra), G. uralensis, and G. inflata, were studied for their differential estrogenic efficacy. The data showed higher estrogenic potency for G. inflata in an alkaline phosphatase induction assay in Ishikawa cells (ERα) and an estrogen responsive element (ERE)-luciferase assay in MDA-MB-231/β41 breast cancer cells (ERβ). Bioassay-guided fractionation of G. inflata led to the isolation of 8-prenylapigenin (3). Surprisingly, a commercial batch of 3 was devoid of estrogenic activity. Quality control by MS and qNMR revealed an incorrect compound, 4'- O-methylbroussochalcone B (10), illustrating the importance of both structural and purity verification prior to any biological investigations. Authentic and pure 3 displayed 14-fold preferential ERβ agonist activity. Quantitative analyses revealed that 3 was 33 times more concentrated in G. inflata compared to the other medicinal licorice extracts. These data suggest that standardization of G. inflata to 3 might enhance the safety and efficacy of G. inflata supplements used for postmenopausal women's health.

Pharmacological activation of estrogen receptor beta augments innate immunity to suppress cancer metastasis

Metastases constitute the greatest causes of deaths from cancer. However, no effective therapeutic options currently exist for cancer patients with metastasis. Estrogen receptor β (ERβ), as a member of the nuclear receptor superfamily, shows potent tumor-suppressive activities in many cancers. To investigate whether modulation of ERβ could serve as a therapeutic strategy for cancer metastasis, we examined whether the selective ERβ agonist LY500307 could suppress lung metastasis of triple-negative breast cancer (TNBC) and melanoma. Mechanistically, while we observed that LY500307 potently induced cell death of cancer cells metastasized to lung in vivo, it does not mediate apoptosis of cancer cells in vitro, indicating that the cell death-inducing effects of LY500307 might be mediated by the tumor microenvironment. Pathological examination combined with flow cytometry assays indicated that LY500307 treatment induced significant infiltration of neutrophils in the metastatic niche. Functional experiments demonstrated that LY500307-treated cancer cells show chemotactic effects for neutrophils and that in vivo neutrophil depletion by Ly6G antibody administration could reverse the effects of LY500307-mediated metastasis suppression. RNA sequencing analysis showed that LY500307 could induce up-regulation of IL-1β in TNBC and melanoma cells, which further triggered antitumor neutrophil chemotaxis. However, the therapeutic effects of LY500307 treatment for suppression of lung metastasis was attenuated in IL1B^-/- murine models, due to failure to induce antitumor neutrophil infiltration in the metastatic niche. Collectively, our study demonstrated that pharmacological activation of ERβ could augment innate immunity to suppress cancer metastatic colonization to lung, thus providing alternative therapeutic options for cancer patients with metastasis.

Hepatocyte-generated 27-hydroxycholesterol promotes the growth of melanoma by activation of estrogen receptor alpha

Cholesterol plays an important role in maintaining normal physiological function of human body. However, excessive intake will induce a series of diseases including cancer. For melanoma, the relationship between hypercholesterolemia and its incidence remains unknown. The cholesterol metabolite 27-hydroxy cholesterol (27-HC) catalyzed by CYP27A1 has been reported to activate estrogen receptor (ER). As studies have indicated that melanoma expresses ER, we designed experiments to explore whether 27-HC could link hypercholesterolemia and melanoma. In this study, hepatocyte-specific CYP27A1^-/- mice were generated by CRISPR/Cas9 technology. The results revealed that high-cholesterol diet induced metabolism disorder and promoted the melanoma growth through 27-HC. Further study found that 27-HC promoted the growth of melanoma cells by activating ERα and eliciting the AKT and MAPK signaling pathway. This study puts forward the important role of 27-HC in the development of melanoma for the first time, links hypercholesterolemia with melanoma progression. The research also provides the rationale for the use of tamoxifen in melanoma therapy. The levels of 27-HC in blood could act as a novel biomarker for tamoxifen treatment in melanoma patients.

Menopausal hormone therapy and risk of melanoma: Do estrogens and progestins have a different role?

The association between use of menopausal hormone therapy (HT) and occurrence of skin malignant melanoma (SMM) is controversial. We investigated the issue in a nationwide cohort of 684,696 Norwegian women, aged 45-79 years, followed from 2004 to 2008. The study was based on linkage between Norwegian population registries. Multivariable Poisson regression models were used to estimate the effect of HT use, different HT types, routes of administration and doses of estrogen and progestin on the risk of SMM. During the median follow-up of 4.8 years, 178,307 (26%) women used HT, and 1,476 incident SMM cases were identified. Current use of HT was associated with increased risk of SMM (rate ratios (RR) = 1.19; 95% confidence interval (CI) 1.03-1.37). Plain estrogen therapy was associated with an increased risk of SMM (RR 1.45; 95% CI 1.21-1.73), both for oral (RR 1.45; 95% CI 1.09-1.93) and vaginal (RR 1.44; 95% CI 1.14-1.84) formulations, while combined estrogen and progestin therapy (EPT) was not (RR 0.91; 95% CI 0.70-1.19). We performed a dose-response analysis of estrogen and progestin in women using tablets, and found that use of estrogens was associated with increased risk (RR 1.24; 95% CI 1.00-1.53 per 1 mg/day) and use of progestins with decreased risk (RR 0.71; 95% CI 0.57-0.89 per 10 mg/month) of SMM. In conclusion, estrogens were associated with increased risk of SMM, while combinations of estrogens and progestins were not. Our results suggest that estrogens and progestins might affect the risk of SMM in opposite ways.

Expression of G protein-coupled oestrogen receptor in melanoma and in pregnancy-associated melanoma

BACKGROUND

The hormone sensitivity of melanoma and the role of 'classical' oestrogen receptor (ER) α and β in tumour progression have been intensively studied with rather contradictory results. The presence of 'non-classical' G protein-coupled oestrogen receptor (GPER) has not been investigated on human melanoma tissues.

OBJECTIVE

To analyse the expression of GPER, ERα and ERβ in pregnancy-associated (PAM) and in non-pregnancy-associated (NPAM) melanomas in correlation with traditional prognostic markers and disease-free survival (DFS).

METHODS

Receptor protein levels were tested using immunohistochemistry in 81 formalin-fixed paraffin-embedded melanoma tissues. PAMs (n = 38) were compared with age- and Breslow thickness-matched cases (n = 43) including non-pregnant women (NPAM-W) (n = 22) and men (NPAM-M) (n = 21). The association between receptor expression and DFS was analysed by uni- and multivariate Cox proportional hazards regression.

RESULTS

G protein-coupled oestrogen receptor was detected both in PAMs and NPAMs. In 39 of the 41 (95.1%) GPER-positive melanomas, GPER and ERβ were co-expressed. GPER/ERβ-positive melanomas were significantly more common in PAM compared to NPAM (P = 0.0001) with no significant difference between genders (P = 0.4383). In PAMs, the distribution of GPER and ERβ was similar (78.4% vs. 81.6%; P = 0.8504), while in NPAM, ERβ was the representative ER (60.5% vs. 27.9%; P = 0.0010) without gender difference (59.1% vs. 61.9%). GPER-/ERβ-positive melanomas were associated with lower Breslow thickness, lower mitotic rate and higher presence of peritumoral lymphocyte infiltration (PLI) compared to GPER-/ERβ-negative cases (P = 0.0156, P = 0.0036 and P = 0.0001) predicting a better DFS (HR = 0.785, 95% CI 0.582-1.058). Despite the significantly higher frequency of GPER and ERβ expression in PAM, no significant difference was found in DFS between PAM and NPAM. All but one case failed to show ERα expression.

CONCLUSIONS

The presence of GPER and its simultaneous expression with ERβ can serve as a new prognostic indicator in a significant subpopulation of melanoma patients.