Fallopian Tube-Derived Tumor Cells Induce Testosterone Secretion from the Ovary, Increasing Epithelial Proliferation and Invasion

Silencing of LINC00467 inhibits cell proliferation in testicular germ cell tumors cells

A significant decrease in LINC00467 expression in testicular germ cell tumors (TGCTs) was found in our previous study in comparison to adjacent tissue. Interestingly, the expression of LINC00467 correlated with the pathological grade of the tumor in TGCT patients. The higher the expression of LINC00467 was, the worse the prognosis of the patients with TGCT was. Despite these findings, the exact role of LINC00467 in the development of TGCTs requires further investigation. LINC00467 expression was downregulated in the NCCIT and TCam-2 cell lines via small interfering RNA (siRNA) silencing. The levels of gene expression were validated using quantitative real-time polymerase chain reaction (qRT-PCR) analyses. Cell proliferation was evaluated by the MTT and Cell Counting Kit-8 (CCK8) assays, whereas flow cytometry was used to assess the effects on the cell cycle. Western blotting analysis was used to detect expression levels of protein. Additionally, RNA-sequencing and bioinformatics methods were used to investigate the mechanism of action of LINC00467 in TGCTs. The suppression of LINC00467 expression resulted in decreased cell proliferation and induced S-phase arrest. Furthermore, the suppression of LINC00467 downregulated proliferating cell nuclear antigen (PCNA), a protein related to cell cycle regulation, while it upregulated p21 expression. In other studies involving dihydrotestosterone (DHT) stimulation, it was observed that DHT could upregulate LINC00467 expression. In addition, silencing of the LINC00467 reversed the effect of testosterone on cell proliferation. The Gene Set Enrichment Analysis (GSEA) revealed that LINC00467 regulated the p53 pathway by modulating the expression of CCNG1. Our study found that LINC00467 regulates cell proliferation by inducing S-phase arrest through the cell cycle-related proteins PCNA and p21. These findings contribute to our understanding of non-coding RNAs mechanisms involved in the development of TGCTs.

Increased Local Testosterone Levels Alter Human Fallopian Tube mRNA Profile and Signaling

Fallopian tube epithelium (FTE) plays a critical role in reproduction and can be the site where High Grade Serous Ovarian Carcinoma (HGSOC) originates. Tumorigenic oviductal cells, which are the murine equivalent of human fallopian tube secretory epithelial cells (FTSEC), enhance testosterone secretion by the ovary when co-cultured with the ovary, suggesting that testosterone is part of the signaling axis between the ovary and FTSEC. Furthermore, testosterone promotes proliferation of oviductal cells. Oral contraceptives, tubal ligation, and salpingectomy, which are all protective against developing ovarian cancer, also decrease circulating levels of androgen. In the current study, we investigated the effect of increased testosterone on FTE and found that testosterone upregulates wingless-type MMTV integration family, member 4 (WNT4) and induces migration and invasion of immortalized human fallopian tube cells. We profiled primary human fallopian tissues grown in the microfluidic system SOLO-microfluidic platform –(MFP) by RNA sequencing and found that p53 and its downstream target genes, such as paired box gene 2 (PAX2), cyclin-dependent kinase inhibitor 1A (CDK1A or p21), and cluster of differentiation 82 (CD82 or KAI1) were downregulated in response to testosterone treatment. A microfluidic platform, the PREDICT-Multi Organ System (PREDICT-MOS) was engineered to support insert technology that allowed for the study of cancer cell migration and invasion through Matrigel. Using this system, we found that testosterone enhanced FTE migration and invasion, which was reversed by the androgen receptor (AR) antagonist, bicalutamide. Testosterone also enhanced FTSEC adhesion to the ovarian stroma using murine ovaries. Overall, these results indicate that primary human fallopian tube tissue and immortalized FTSEC respond to testosterone to shift expression of genes that regulate invasion, while leveraging a new strategy to study migration in the presence of dynamic fluid flow.

Fallopian tube secreted protein affects ovarian metabolites in high grade serous ovarian cancer

High grade serous ovarian cancer (HGSOC), the most lethal histotype of ovarian cancer, frequently arises from fallopian tube epithelial cells (FTE). Once transformed, tumorigenic FTE often migrate specifically to the ovary, completing the crucial primary metastatic step and allowing the formation of the ovarian tumors after which HGSOC was originally named. As only the fimbriated distal ends of the fallopian tube that reside in close proximity to the ovary develop precursor lesions such as serous tubal intraepithelial carcinomas, this suggests that the process of transformation and primary metastasis to the ovary is impacted by the local microenvironment. We hypothesize that chemical cues, including small molecules and proteins, may help stimulate the migration of tumorigenic FTE to the ovary. However, the specific mediators of this process are still poorly understood, despite a recent growth in interest in the tumor microenvironment. Our previous work utilized imaging mass spectrometry (IMS) to identify the release of norepinephrine (NE) from the ovary in co-cultures of tumorigenic FTE cells with an ovarian explant. We predicted that tumorigenic FTE cells secreted a biomolecule, not produced or produced with low expression by non-tumorigenic cells, that stimulated the ovary to release NE. As such, we utilized an IMS mass-guided bioassay, using NE release as our biological marker, and bottom-up proteomics to demonstrate that a secreted protein, SPARC, is a factor produced by tumorigenic FTE responsible for enhancing release of ovarian NE and influencing primary metastasis of HGSOC. This discovery highlights the bidirectional interplay between different types of biomolecules in the fallopian tube and ovarian microenvironment and their combined roles in primary metastasis and disease progression.

Irilone, a Red Clover Isoflavone, Combined with Progesterone Enhances PR Signaling through the Estrogen and Glucocorticoid Receptors

Trifolium pratense L. (red clover) is a popular botanical supplement used for women's health. Irilone isolated from red clover previously demonstrated progestogenic potentiation activity. In this study, irilone enhanced progesterone signaling was determined to not occur due to post-translational phosphorylation or by reducing progesterone receptor (PR) protein levels but instead increased PR protein levels in T47D breast cancer cells, which could be blocked by estrogen receptor (ER) antagonists, suggesting an ER dependent effect. Further, irilone increased luciferase activity from a hormone responsive element in a cell line that lacked ER and PR but expressed the glucocorticoid receptor (GR). A siRNA knockdown of GR in Ishikawa PR-B endometrial cancer cells reduced irilone's ability to enhance progesterone signaling. In an ovariectomized CD-1 mouse model, irilone did not induce uterine epithelial cell proliferation. The mechanism of action of irilone gives insight into PR crosstalk with other steroid hormone receptors, which can be important for understanding botanicals that are used for women's health.