Genetic Polymorphism in Sex Hormone-binding Globulin With a Prognosis of Androgen Deprivation Therapy in Metastatic Prostate Cancer Among Japanese Men

Lower pretreatment serum testosterone level predicts poor prognosis in the patients with metastatic hormone-sensitive prostate cancer undergoing androgen deprivation therapy

OBJECTIVE

This study aimed to reveal the association between pretreatment serum testosterone levels and prognosis in patients with metastatic hormone-sensitive prostate cancer treated with androgen deprivation therapy.

METHODS

A total of 91 patients were included in this retrospective study. Clinical data were obtained through chart review. Multivariate cox proportional hazards analyses addressed the impact of variables on castration-resistant prostate cancer-free and overall survivals.

RESULTS

During a median follow-up of 41.7 months, 61 (67%) and 49 (54%) patients developed castration-resistant prostate cancer and died, respectively. The median castration-resistant prostate cancer-free and overall survivals were 15.5 and 59.9 months, respectively. The cutoff value for discriminating between low- and high-testosterone levels was determined as 450 ng/dl by calculating the receiver operating characteristic curve. Patients in the low-testosterone group (n = 37) had a significantly higher body mass index, worse comorbidities represented by the higher Charlson comorbidity index and higher serum lactate dehydrogenase levels, than those in the high-testosterone group (n = 54). Castration-resistant prostate cancer free and overall survivals were significantly shorter in the low-testosterone group than in the high-testosterone group (P = 0.021 and P < 0.001, respectively). Multivariate analysis identified testosterone level of <450 ng/dl as an independent factor predicting development of castration-resistant prostate cancer (hazard ratio 2.28, P = 0.007), along with high-volume disease and Gleason score 9-10. Similarly, testosterone level of <450 ng/dl was independently associated with shorter overall survival (hazard ratio 2.84, P = 0.006), along with higher Charlson comorbidity index, visceral metastasis and higher alkaline phosphatase level.

CONCLUSIONS

Lower baseline serum testosterone levels predict poor prognosis in patients with metastatic hormone-sensitive prostate cancer.

Lower androgen levels promote abnormal cartilage development in female patients with adolescent idiopathic scoliosis

Background

Adolescent idiopathic scoliosis (AIS) is a disease characterized by changes in the three-dimensional structure of the spine. Studies have shown that the development of AIS might be associated with genetic, biomechanics, endocrine factors and abnormal bone or cartilage development.

Methods

Blood samples collected from 301 female patients (161 females with AIS and 140 females without AIS) were used for genotyping. Forty-eight serum samples from 161 females with AIS and 40 serum samples from 140 females without AIS were subjected to enzyme-linked immunosorbent assays (ELISAs). We also evaluated 32 facet joints (18 females with AIS and 14 females without AIS from the 301 female patients) using immunohistochemistry, Western blotting, and isolation of human primary chondrocytes, among other methods. We treated the AIS primary chondrocytes with dihydrotestosterone (DHT) to verify the relationship among androgen, the androgen receptor (AR), and its downstream pathway proteins.

Results

The serum androgen level in the AIS group was significantly decreased (1.94±0.09 vs. 2.284±0.103) compared with that in the non-AIS (control) group. The single nucleotide polymorphism genotyping results showed that the mutation rates of rs6259 between the AIS and control groups were significantly different (G/G genotype: 48.4% vs. 42.1%, G/A genotype: 40.4% vs. 35.7%, P<0.05). The levels of interleukin (IL)-6 and metalloproteinase (MMP)-13 were increased in the cartilage of AIS patients, and these patients also exhibited decreased AR levels. The cell experiment results showed that androgen reduced the degree of abnormal cartilage development in female AIS patients through the AR/IL-6/signal transducer and activator of transcription 3 (STAT3) signaling pathway.

Conclusions

Our study provides a new perspective on the pathogenesis of AIS and indicates that decreased androgen levels in female AIS patients play a potential role in the development of AIS via the AR/IL-6/STAT3 signaling pathway.

Genetic Polymorphisms and Pharmacotherapy for Prostate Cancer

The therapeutic landscape of pharmacotherapy for prostate cancer has dramatically evolved, and multiple therapeutic options have become available for prostate cancer patients. Therefore, useful biomarkers to identify suitable candidates for treatment are required to maximize the efficacy of pharmacotherapy. Genetic polymorphisms such as single-nucleotide polymorphisms (SNPs) and tandem repeats have been shown to influence the therapeutic effects of pharmacotherapy for prostate cancer patients. For example, genetic polymorphisms in the genes involved in androgen receptor signaling are reported to be associated with the therapeutic outcome of androgen-deprivation therapy as well as androgen receptor-pathway inhibitors. In addition, SNPs in genes involved in drug metabolism and efflux pumps are associated with therapeutic effects of taxane chemotherapy. Thus, genetic polymorphisms such as SNPs are promising biomarkers to realize personalized medicine. Here, we overview the current findings on the influence of genetic polymorphisms on the outcome of pharmacotherapy for prostate cancer and discuss current issues as well as future visions in this field.

Research progress on the relationship between sex hormone-binding globulin and male reproductive system diseases

Sex hormone-binding globulin, also known as testosterone-estradiol-binding globulin, is a multifunctional protein synthesised by hepatocytes. Sex hormone-binding globulin specifically binds and transports sex hormones to regulate plasma bioactive sex hormone levels and affects their bioavailability. As male sex hormone expression is dominated by testosterone, the binding of sex hormone-binding globulin with testosterone leads to the reduction in bioavailable testosterone, which cannot fulfil its physiological roles, thereby resulting in male infertility, erectile and gonadal dysfunction, prostate cancer and other male reproductive system diseases. Sex hormone-binding globulin may be involved in the pathogenesis of male reproductive system diseases, seriously affecting the quality of life of men. In this article, we review the association between sex hormone-binding globulin and male reproductive system diseases.