Epigenetic abnormalities play a vital role in the progression of ovarian cancer. Lysine-specific demethylase 1 (LSD1/KDM1A) acts as an epigenetic regulator and is overexpressed in ovarian tumors. However, the upstream regulator of LSD1 expression in this cancer remains elusive. Here, we show that epidermal growth factor (EGF) signaling upregulates LSD1 protein levels in SKOV3 and HO8910 ovarian cancer cells overexpressing both LSD1 and the EGF receptor. This effect is correlated with a decrease in the dimethylation of H3K4, a major substrate of LSD1, in an LSD1-dependent manner. We also show that inhibition of PI3K/AKT, but not MEK, abolishes the EGF-induced upregulation of LSD1 and cell migration, indicating that the PI3K/PDK1/AKT pathway mediates the EGF-induced expression of LSD1 and cell migration. Significantly, LSD1 knockdown or inhibition of LSD1 activity impairs both intrinsic and EGF-induced cell migration in SKOV3 and HO8910 cells. These results highlight a novel mechanism regulating LSD1 expression and identify LSD1 as a promising therapeutic target for treating metastatic ovarian cancer driven by EGF signaling.

Solamargine (SM), a steroidal alkaloid glycoside extracted from the traditional Chinese herb Solanum incanum, has been evidenced to inhibit the growth and induce apoptosis in a number of human cancer cell lines. In the present study, the anticancer effect of SM and underlying molecular mechanism of SM‑induced apoptosis were investigated on the human hepatocellular carcinoma cells, SMMC7721 and HepG2. The proliferation effects of SM on the SMMC7721 and HepG2 cell lines were evaluated using MTT and colony formation assays. In addition, the percentage of apoptosis was measured using an Annexin V/propidium iodide staining method and the cell cycle distribution mediated by SM was analyzed using flow cytometry. The expression levels of B‑cell lymphoma‑2 (Bcl‑2), Bcl‑2‑associated X protein (Bax), caspase‑3, caspase‑9, proliferating cell nuclear antigen (pcna) and Ki67 proteins were examined to further demonstrate the proliferate and apoptosis effects of SM on the hepatoma cells. The results indicated that SM effectively inhibited hepatoma cell proliferation and promoted apoptosis. SM resulted in cell cycle arrest at the G2/M phase in the two cell lines. In addition, SM downregulated the levels of proliferation‑associated (Ki67 and pcna) and anti‑apoptotic (Bcl‑2) proteins, and promoted the activity of apoptosis‑associated proteins (Bax, caspase‑3 and caspase‑9). Therefore, the activation of the Bcl‑2/Bax and caspase signaling pathways may be involved in the SM-induced apoptosis of hepatoma cells.

SET domain-containing 5 (SETD5) is an uncharacterized member of the protein lysine methyltransferase family and is best known for its transcription machinery by methylating histone H3 on lysine 36 (H3K36). These well-characterized functions of SETD5 are transcription regulation, euchromatin formation, and RNA elongation and splicing. SETD5 is frequently mutated and hyperactive in both human neurodevelopmental disorders and cancer, and could be down-regulated by degradation through the ubiquitin-proteasome pathway, but the biochemical mechanisms underlying such dysregulation are rarely understood. Herein, we provide an update on the particularities of SETD5 enzymatic activity and substrate specificity concerning its biological importance, as well as its molecular and cellular impact on normal physiology and disease, with potential therapeutic options.

Lysine-specific demethylase 1 (LSD1) plays a key role in cell proliferation, differentiation and carcinogenesis. In the present study we revealed that LSD1 functioned as an autophagy suppressor in ovarian cancer HO8910 cells. Pharmacological inhibition or genetic knockdown of LSD1 resulted in the elevation of the LC3‑II protein, enhancement of autophagosomal formation and stimulation of the autophagic flux. In addition, knockdown of LSD1 further promoted the serum starvation- and rapamycin-induced autophagy. Furthermore, we demonstrated that LSD1 regulated autophagy via the mTOR signaling pathway. Collectively, our findings identified LSD1 as a novel negative regulator of autophagy through the mTOR signaling pathway in ovarian cancer HO8910 cells and indicated that LSD1 may function as a driving factor of ovarian cancer progression via deregulating autophagy.

Lysine‑specific demethylase 1 (LSD1) functions as a transcriptional coregulator by modulating histone methylation and has been associated with numerous high‑risk cancers. Previously, our group and others identified LSD1 as an upregulated gene in ovarian cancer, and reported that the upregulation of LSD1 was associated with poor prognosis of patients with ovarian cancer. However, the role of LSD1 in ovarian cancer requires further investigation. The present study revealed that the overexpression of LSD1 significantly promoted the proliferation of SKOV3 ovarian cancer cells, while knockdown of LSD1 markedly inhibited cell proliferation and potentiated cisplatin‑induced cell apoptosis, supporting LSD1 as an oncogenic protein in ovarian cancer. Mechanistic studies have indicated that LSD1 modulates the expression of cyclin dependent kinase inhibitor 1, Survivin, B‑cell lymphoma‑2 (Bcl‑2) and Bcl‑2‑associated X genes, which are known regulators of cell proliferation. Furthermore, LSD1 knockdown plus cisplatin synergistically impaired cell migration via the induction of the epithelial marker E‑cadherin and inhibition of the mesenchymal markers, snail family transcriptional repressor 1 and Vimentin. These data of the present study indicated LSD1 as a potential regulator of ovarian cancer cell progression and suggested an unfavorable role of LSD1 in cisplatin‑based regimens.