Dihydrotestosterone Induces Proliferation, Migration, and Invasion of Human Glioblastoma Cell Lines

Gender differences in gliomas: From epidemiological trends to changes at the hormonal and molecular levels

Gender plays a crucial role in the occurrence and development of cancer, as well as in the metabolism of nutrients and energy. Men and women display significant differences in the incidence, prognosis, and treatment response across various types of cancer, including certain sex-specific tumors. It has been observed that male glioma patients have a higher incidence and worse prognosis than female patients, but there is currently a limited systematic evaluation of sex differences in gliomas. The purpose of this study is to provide an overview of the association between fluctuations in sex hormone levels and changes in their receptor expression with the incidence, progression, treatment, and prognosis of gliomas. Estrogen may have a protective effect on glioma patients, while exposure to androgens increases the risk of glioma. We also discussed the specific genetic and molecular differences between genders in terms of the malignant nature and prognosis of gliomas. Factors such as TP53, MGMT methylation status may play a crucial role. Therefore, it is essential to consider the gender of patients while treating glioma, particularly the differences at the hormonal and molecular levels. This approach can help in the adoption of an individualized treatment strategy.

A novel L-shaped ortho-quinone analog suppresses glioblastoma progression by targeting acceleration of AR degradation and regulating PI3K/AKT pathway

Glioblastoma (GBM) is a primary intracranial malignant tumor with the highest mortality and morbidity among all malignant central nervous system tumors. Tanshinone IIA is a fat-soluble active ingredient obtained from Salvia miltiorrhiza, which has an inhibitory effect against various cancers. We designed and synthesized a novel L-shaped ortho-quinone analog TE5 with tanshinone IIA as the lead compound and tested its antitumor activity against GBM. The results indicated that TE5 effectively inhibited the proliferation, migration, and invasion of GBM cells, and demonstrated low toxicity in vitro. We found that TE5 may bind to androgen receptors and promote their degradation through the proteasome. Inhibition of the PI3K/AKT signaling pathway was also observed in TE5 treated GBM cells. Additionally, TE5 arrested the cell cycle at the G2/M phase and induced mitochondria-dependent apoptosis. In vivo experiments further confirmed the anti-tumor activity, safety, and effect on androgen receptor level of TE5 in animal models of GBM. Our results suggest that TE5 may be a potential therapeutic drug to treat GBM.

Integrative multi-omics characterization reveals sex differences in glioblastoma

BACKGROUND

Glioblastoma (GBM) is the most common and lethal primary brain tumor in adults, with limited treatment modalities and poor prognosis. Recent studies have highlighted the importance of considering sex differences in cancer incidence, prognosis, molecular disparities, and treatment outcomes across various tumor types, including colorectal adenocarcinoma, lung adenocarcinoma, and GBM.

METHODS

We performed comprehensive analyses of large-scale multi-omics data (genomic, transcriptomic, and proteomic data) from TCGA, GLASS, and CPTAC to investigate the genetic and molecular determinants that contribute to the unique clinical properties of male and female GBM patients.

RESULTS

Our results revealed several key differences, including enrichments of MGMT promoter methylation, which correlated with increased overall and post-recurrence survival and improved response to chemotherapy in female patients. Moreover, female GBM exhibited a higher degree of genomic instability, including aneuploidy and tumor mutational burden. Integrative proteomic and phosphor-proteomic characterization uncovered sex-specific protein abundance and phosphorylation activities, including EGFR activation in males and SPP1 hyperphosphorylation in female patients. Lastly, the identified sex-specific biomarkers demonstrated prognostic significance, suggesting their potential as therapeutic targets.

CONCLUSIONS

Collectively, our study provides unprecedented insights into the fundamental modulators of tumor progression and clinical outcomes between male and female GBM patients and facilitates sex-specific treatment interventions. Highlights Female GBM patients were characterized by increased MGMT promoter methylation and favorable clinical outcomes compared to male patients. Female GBMs exhibited higher levels of genomic instability, including aneuploidy and TMB. Each sex-specific GBM is characterized by unique pathway dysregulations and molecular subtypes. EGFR activation is prevalent in male patients, while female patients are marked by SPP1 hyperphosphorylation.

Cancer Stem Cells and Androgen Receptor Signaling: Partners in Disease Progression

Cancer stem cells exhibit self-renewal, tumorigenesis, and a high differentiation potential. These cells have been detected in every type of cancer, and different signaling pathways can regulate their maintenance and proliferation. Androgen receptor signaling plays a relevant role in the pathophysiology of prostate cancer, promoting cell growth and differentiation processes. However, in the case of prostate cancer stem cells, the androgen receptor negatively regulates their maintenance and self-renewal. On the other hand, there is evidence that androgen receptor activity positively regulates the generation of cancer stem cells in other types of neoplasia, such as breast cancer or glioblastoma. Thus, the androgen receptor role in cancer stem cells depends on the cellular context. We aimed to analyze androgen receptor signaling in the maintenance and self-renewal of different types of cancer stem cells and its action on the expression of transcription factors and surface markers associated with stemness.

Beyond Prostate Cancer: An Androgen Receptor Splice Variant Expression in Multiple Malignancies, Non-Cancer Pathologies, and Development

Multiple studies have demonstrated the importance of androgen receptor (AR) splice variants (SVs) in the progression of prostate cancer to the castration-resistant phenotype and their utility as a diagnostic. However, studies on AR expression in non-prostatic malignancies uncovered that AR-SVs are expressed in glioblastoma, breast, salivary, bladder, kidney, and liver cancers, where they have diverse roles in tumorigenesis. AR-SVs also have roles in non-cancer pathologies. In granulosa cells from women with polycystic ovarian syndrome, unique AR-SVs lead to an increase in androgen production. In patients with nonobstructive azoospermia, testicular Sertoli cells exhibit differential expression of AR-SVs, which is associated with impaired spermatogenesis. Moreover, AR-SVs have been identified in normal cells, including blood mononuclear cells, neuronal lipid rafts, and the placenta. The detection and characterization of AR-SVs in mammalian and non-mammalian species argue that AR-SV expression is evolutionarily conserved and that AR-SV-dependent signaling is a fundamental regulatory feature in multiple cellular contexts. These discoveries argue that alternative splicing of the AR transcript is a commonly used mechanism that leads to an expansion in the repertoire of signaling molecules needed in certain tissues. Various malignancies appropriate this mechanism of alternative AR splicing to acquire a proliferative and survival advantage.

Update for astrocytomas: medical and surgical management considerations

Astrocytomas include a wide range of tumors with unique mutations and varying grades of malignancy. These tumors all originate from the astrocyte, a star-shaped glial cell that plays a major role in supporting functions of the central nervous system (CNS), including blood-brain barrier (BBB) development and maintenance, water and ion regulation, influencing neuronal synaptogenesis, and stimulating the immunological response. In terms of epidemiology, glioblastoma (GB), the most common and malignant astrocytoma, generally occur with higher rates in Australia, Western Europe, and Canada, with the lowest rates in Southeast Asia. Additionally, significantly higher rates of GB are observed in males and non-Hispanic whites. It has been suggested that higher levels of testosterone observed in biological males may account for the increased rates of GB. Hereditary syndromes such as Cowden, Lynch, Turcot, Li-Fraumeni, and neurofibromatosis type 1 have been linked to increased rates of astrocytoma development. While there are a number of specific gene mutations that may influence malignancy or be targeted in astrocytoma treatment, O 6-methylguanine-DNA methyltransferase (MGMT) gene function is an important predictor of astrocytoma response to chemotherapeutic agent temozolomide (TMZ). TMZ for primary and bevacizumab in the setting of recurrent tumor formation are two of the main chemotherapeutic agents currently approved in the treatment of astrocytomas. While stereotactic radiosurgery (SRS) has debatable implications for increased survival in comparison to whole-brain radiotherapy (WBRT), SRS demonstrates increased precision with reduced radiation toxicity. When considering surgical resection of astrocytoma, the extent of resection (EoR) is taken into consideration. Subtotal resection (STR) spares the margins of the T1 enhanced magnetic resonance imaging (MRI) region, gross total resection (GTR) includes the margins, and supramaximal resection (SMR) extends beyond the margin of the T1 and into the T2 region. Surgical resection, radiation, and chemotherapy are integral components of astrocytoma treatment.

Androgen Receptor Expression in the Various Regions of Resected Glioblastoma Multiforme Tumors and in an In Vitro Model

Glioblastoma multiforme (GBM) is a malignant glioma, difficult to detect and with the lowest survival rates among gliomas. Its greater incidence among men and its higher survival rate among premenopausal women suggest that it may be associated with the levels of androgens. As androgens stimulate the androgen receptor (AR), which acts as a transcription factor, the aim of this study was the investigate the role of AR in the progression of GBM. The study was conducted on tissues collected from three regions of GBM tumors (tumor core, enhancing tumor region, and peritumoral area). In addition, an in vitro experiment was conducted on U-87 cells under various culture conditions (necrotic, hypoxic, and nutrient-deficient), mimicking the conditions in a tumor. In both of the models, androgen receptor expression was determined at the gene and protein levels, and the results were confirmed by confocal microscopy and immunohistochemistry. AR mRNA expression was higher under nutrient-deficient conditions and lower under hypoxic conditions in vitro. However, there were no differences in AR protein expression. No differences in AR mRNA expression were observed between the tested tumor structures taken from patients. No differences in AR mRNA expression were observed between the men and women. However, AR protein expression in tumors resected from patients was higher in the enhancing tumor region and in the peritumoral area than in the tumor core. In women, higher AR expression was observed in the peritumoral area than in the tumor core. AR expression in GBM tumors did not differ significantly between men and women, which suggests that the higher incidence of GBM in men is not associated with AR expression. In the group consisting of men and women, AR expression varied between the regions of the tumor: AR expression was higher in the enhancing tumor region and in the peritumoral area than in the tumor core, showing a dependence on tumor conditions (hypoxia and insufficient nutrient supply).

Enzalutamide Induces Apoptotic Insults to Human Drug-Resistant and -Sensitive Glioblastoma Cells via an Intrinsic Bax-Mitochondrion-Cytochrome C Caspase Cascade Activation Pathway

Glioblastoma multiforme (GBM) is the most common and malignant brain tumor. Temozolomide (TMZ) is the first-line chemotherapeutic drug for treating GBM. However, drug resistance is still a challenging issue in GBM therapy. Our preliminary results showed upregulation of androgen receptor (AR) gene expression in human GBM tissues. This study was designed to evaluate the effects of enzalutamide, a specific inhibitor of the AR, on killing drug-resistant and -sensitive glioblastoma cells and the possible mechanisms. Data mining from The Cancer Genome Atlas (TCGA) database revealed upregulation of AR messenger (m)RNA and protein expressions in human GBM tissues, especially in male patients, compared to normal human brains. In addition, expressions of AR mRNA and protein in human TMZ-sensitive U87 MG and -resistant U87 MG-R glioblastoma cells were elevated compared to normal human astrocytes. Exposure of human U87 MG and U87 MG-R cells to enzalutamide concentration- and time-dependently decreased cell viability. As to the mechanism, enzalutamide killed these two types of glioblastoma cells via an apoptotic mechanism. Specifically, exposure to enzalutamide augmented enzyme activities of caspase-9 rather than those of caspase-8. Moreover, enzalutamide successively triggered an elevation in levels of the proapoptotic Bax protein, a reduction in the mitochondrial membrane potential, release of cytochrome c, cascade activation of caspases-3 and -6, DNA fragmentation, and cell apoptosis in human TMZ-sensitive and -resistant glioblastoma cells. Pretreatment with Z-VEID-FMK, an inhibitor of caspase-6, caused significant attenuations in enzalutamide-induced morphological shrinkage, DNA damage, and apoptotic death. Taken together, this study showed that enzalutamide could significantly induce apoptotic insults to human drug-resistant and -sensitive glioblastoma cells via an intrinsic Bax-mitochondrion-cytochrome c-caspase cascade activation pathway. Enzalutamide has the potential to be a drug candidate for treating GBM by targeting the AR signaling axis.

Testosterone Augments Propagation of Toxoplasma gondii in Glioblastoma Cells In Vitro

PURPOSE

Toxoplasmosis can induce various hormonal and behavioral alterations in humans and rodents. Previous studies revealed alterations of sex hormones; especially testosterone, in infected humans and rodents, but little is known about the effects of sex hormones on the propagation of T. gondii. Hence, we aimed to investigate whether testosterone and progesterone influence on T. gondii propagation in neural cells.

METHODS

The glioblastoma cells (U-87MG) were treated with different concentrations of testosterone and progesterone and the infection was done by tachyzoites of the RH strain of T. gondii. The number of infected cells, viability of T. gondii-infected cells, and parasite burden were measured by direct counting under a light microscope, MTT assay, and quantitative real-time PCR (qPCR), respectively.

RESULTS

The results showed that testosterone at concentrations of 100 and 250 nM significantly increased the number of infected cells and parasite burden 24 and 48 h post-treatment compared to untreated controls. Progesterone had no significant effects in the same manner.

CONCLUSION

The results indicated that testosterone could augment the propagation of T. gondii in in vitro.

Identification of Gender-Specific Molecular Differences in Glioblastoma (GBM) and Low-Grade Glioma (LGG) by the Analysis of Large Transcriptomic and Epigenomic Datasets

Differences in the incidence and outcome of glioma between males and females are well known, being more striking for glioblastoma (GB) than low-grade glioma (LGG). The extensive and well-annotated data in publicly available databases enable us to analyze the molecular basis of these differences at a global level. Here, we have analyzed The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) databases to identify molecular indicators for these gender-based differences by different methods. Based on the nature of data available/accessible, the transcriptomic profile was studied in TCGA by using DeSeq2 and in CGGA by T-test, after correction based. Only IDH1 wild-type tumors were studied in CGGA. Using weighted gene co-expression network analysis (WGCNA), network analysis was done, followed by the assessment of modular differential connectivity. Differentially affected signaling pathways were identified. The gender-based effects of differentially expressed genes on survival were determined. DNA methylation was studied as an indicator of gender-based epigenetic differences. The results clearly showed gender-based differences in both GB and LGG, whatever method or database was used. While there were differences in the results obtained between databases and methods used, some major signaling pathways such as Wnt signaling and pathways involved in immune processes and the adaptive immune response were common to different assessments. There was also a differential gender-based influence of several genes on survival. Also, the autosomal genes NOX, FRG1BP, and AL354714.2 and X-linked genes such as PUDP, KDM6A, DDX3X, and SYAP1 had differential DNA methylation and expression profile in male and female GB, while for LGG, these included autosomal genes such as CNIH3 and ANKRD11 and X-linked genes such as KDM6A, MAOB, and EIF2S3. Some, such as FGF13 and DDX3X, have earlier been shown to have a role in tumor behavior, though their dimorphic effects in males and females have not been identified. Our study thus identifies several crucial differences between male and female glioma, which could be validated further. It also highlights that molecular studies without consideration of gender can obscure critical elements of biology and emphasizes the importance of parallel but separate analyses of male and female glioma.

Glioblastoma cells express crucial enzymes involved in androgen synthesis: 3β-hydroxysteroid dehydrogenase, 17-20α-hydroxylase, 17β-hydroxysteroid dehydrogenase and 5α-reductase

Glioblastoma (GB) is the most common and aggressive primary brain tumour in adult humans. Therapeutic resistance and tumour recurrence after surgical removal contribute to poor prognosis for glioblastoma patients. Men are known to be more likely than women to develop an aggressive form of GB, and differences in sex steroids have emerged as a leading explanation for this finding. Studies indicate that the metabolism and proliferation of GB‐derived cells are increased by sex steroids, the expression of androgen receptors (ARs) and the synthesis of androgens and oestrogens, suggesting that these hormones have a role in the tumour pathogenesis. The expression of aromatase, the enzyme that converts androgens to oestrogens, has been reported in glial cells and GB cell lines. Thus, it was necessary to test whether the steroidogenic enzymes involved in androgen synthesis are expressed in GB cells. Therefore, here, we investigated the expression of four key enzymes involved in androgen synthesis in human‐derived GB cells. U87 cells were cultured in Dulbecco's modified Eagle medium plus foetal bovine serum and antibiotics on slides for immunocytochemistry or immunofluorescence. U87, LN229 and C6 cells were also cultured in multi‐well chambers to obtain proteins for Western blotting. We used primary antibodies against 3β‐hydroxysteroid dehydrogenase (3β‐HSD), 17α‐hydroxilase/17,20‐lyase (P450c17), 17β‐hydroxysteroid dehydrogenase (17β‐HSD) and 5α‐reductase. Immunocytochemistry, and immunofluorescence results revealed that glioblastoma cells express 3β‐HSD, P450c17, 17β‐HSD and 5α‐reductase proteins in their cytoplasm. Moreover, Western blot analyses revealed bands corresponding to the molecular weight of these four enzymes in the three GB cell lines. Thus, glioblastoma cells have the key enzymatic machinery necessary to synthesize androgens, and these enzymes might be useful targets for new therapeutic approaches.

Antioxidant and Antiproliferative Activity of Finasteride against Glioblastoma Cells

Glioblastoma is an actively growing and aggressive brain tumor with a high propensity of recurrence. Although the surgical removal of tumor mass is the primary therapeutic option against glioblastoma, supportive pharmacotherapy is highly essential due to incredibly infiltrative characteristic of glioblastoma. Temozolomide, an FDA-approved alkylating agent, has been used as a first-line standard pharmacological approach, but several evident limitations were repeatedly reported. Despite additional therapeutic options suggested, there are no medications that successfully prevent a recurrence of glioblastoma and increase the five-year survival rate. In this study, we tested the possibility that finasteride has the potential to be developed as an anti-glioblastoma drug. Finasteride, an FDA-approved medication for the treatment of benign prostate hyperplasia and androgenic alopecia, is already known to pass through the blood-brain barrier and possess antiproliferative activity of prostate epithelial cells. We showed that finasteride inhibited the maintenance of glioma stem-like cells and repressed the proliferation of glioblastoma. Mechanistically, finasteride lowered intracellular ROS level by upregulating antioxidant genes, which contributed to inefficient β-catenin accumulation. Downregulated β-catenin resulted in the reduction in stemness and cell growth in glioblastoma.

Insights into the role of estrogens and androgens in glial tumorigenesis

Gliomas are more common in males than in females. Emerging evidence from several studies in vitro and in vivo have shown the role of estrogens and androgens in glial tumorigenesis. In recent times, studies have also shed light on the actions of estrogen receptors, alpha and beta, and androgen receptor. Here, we provide a comprehensive overview of the research hitherto on estrogens and androgens along with an emphasis on their receptors in glioma pathophysiology. Studies with conflicting results are discussed and future possibilities are put forward. A collective understanding of the studies on these steroid hormones in glioma may serve to create an amalgamated therapeutic approach; and thereby, augment the efforts in tackling this deadly disease.

Impact of sex in the prevalence and progression of glioblastomas: the role of gonadal steroid hormones

BACKGROUND

As in other types of cancers, sex is an essential factor in the origin and progression of glioblastomas. Research in the field of endocrinology and cancer suggests that gonadal steroid hormones play an important role in the progression and prevalence of glioblastomas. In the present review, we aim to discuss the actions and mechanism triggered by gonadal steroid hormones in glioblastomas.

MAIN BODY

Glioblastoma is the most common malignant primary brain tumor. According to the epidemiological data, glioblastomas are more frequent in men than in women in a 1.6/1 proportion both in children and adults. This evidence, and the knowledge about sex influence over the prevalence of countless diseases, suggest that male gonadal steroid hormones, such as testosterone, promote glioblastomas growth. In contrast, a protective role of female gonadal steroid hormones (estradiol and progesterone) against glioblastomas has been questioned. Several pieces of evidence demonstrate a variety of effects induced by female and male gonadal steroid hormones in glioblastomas. Several studies indicate that pregnancy, a physiological state with the highest progesterone and estradiol levels, accelerates the progression of low-grade astrocytomas to glioblastomas and increases the symptoms associated with these tumors. In vitro studies have demonstrated that progesterone has a dual role in glioblastoma cells: physiological concentrations promote cell proliferation, migration, and invasion while very high doses (out physiological range) reduce cell proliferation and increases cell death.

CONCLUSION

Gonadal steroid hormones can stimulate the progression of glioblastomas through the increase in proliferation, migration, and invasion. However, the effects mentioned above depend on the concentrations of these hormones and the receptor involved in hormone actions. Estradiol and progesterone can exert promoter or protective effects while the role of testosterone has been always associated to glioblastomas progression.

Astrocytoma: A Hormone-Sensitive Tumor?

Astrocytomas and, in particular, their most severe form, glioblastoma, are the most aggressive primary brain tumors and those with the poorest vital prognosis. Standard treatment only slightly improves patient survival. Therefore, new therapies are needed. Very few risk factors have been clearly identified but many epidemiological studies have reported a higher incidence in men than women with a sex ratio of 1:4. Based on these observations, it has been proposed that the neurosteroids and especially the estrogens found in higher concentrations in women's brains could, in part, explain this difference. Estrogens can bind to nuclear or membrane receptors and potentially stimulate many different interconnected signaling pathways. The study of these receptors is even more complex since many isoforms are produced from each estrogen receptor encoding gene through alternative promoter usage or splicing, with each of them potentially having a specific role in the cell. The purpose of this review is to discuss recent data supporting the involvement of steroids during gliomagenesis and to focus on the potential neuroprotective role as well as the mechanisms of action of estrogens in gliomas.