Anti-Cancer Effects of CDK4/6 Inhibitor LEE011 and Chemotherapy Drugs on Lymphocytic Leukemia L1210 Cells.

BACKGROUND/AIM: Chronic lymphocytic leukemia is a slowly-progressing disease in which symptoms often do not manifest until years after disease onset. In advanced stages, infection and bleeding are common. Past studies have shown that the interaction between CDK4/6 inhibitors and chemotherapy drugs can enhance the anti-tumor efficacy of drugs and limit toxicity. Therefore, in this study, the treatment effects of combining the CDK4/6 inhibitor LEE011 with chemotherapy drugs bendamustine or hydroxyurea were investigated in vitro. MATERIALS AND METHODS: The mouse lymphocytic leukemia cell line L1210 was treated with LEE011 combined with hydroxyurea or bendamustine. Western blot and flow cytometry were performed to elucidate the mechanisms behind tumor suppression. RESULTS: LEE011 combined with hydroxyurea or bendamustine significantly inhibited proliferation of L1210 cell lines in a concentration- and time-dependent manner as well as increased the arrest of cells in G1 and S phases. The combination of LEE011 with hydroxyurea also reduced the phosphorylation of Rb while increased the expression of total Rb protein. Furthermore, reduced expression of GPX4, which is a key protein in ferroptosis, indicates that the tumor suppression effects of this drug combination could involve ferroptosis. CONCLUSION: CDK4/6 inhibitor LEE011 treatment alone may not be a suitable treatment option for lymphocytic leukemia; however, our findings in vitro support the combination of LEE011 with chemotherapy drugs to enhance anti-tumor activity in lymphocytic leukemia.

Hinokitiol Inhibits the Viability of Oral Squamous Carcinoma Cells by Inducing Apoptosis and Autophagy.

BACKGROUND/AIM: Oral squamous cell carcinoma (OSCC) is one of the deadliest cancers, with approximately ~500,000 new diagnosed cases and 145,000 deaths worldwide, per year. The incidence of new cases continues to increase in developing countries. This study aimed to investigate the effect of hinokitiol on cell viability in OSCC cells. MATERIALS AND METHODS: The anticancer effect and mechanism of action of hinokitiol in OSCC cells were analyzed by cell viability assays and cell cycle analysis using flow cytometry, while apoptosis and autophagy-related protein expression was measured using western blot. RESULTS: The results showed that hinokitiol concentration-dependently reduced the viability of SCC4 and SCC25 cells by downregulating the levels of cell-cycle mediators, such as cyclin B1, cyclin D1 and cyclin-dependent kinase-1 (CDK1). Furthermore, hinokitiol promoted apoptosis in SCC25 cells based on the presence of active cleaved caspase-3. Hinokitiol also induced autophagy by promoting the accumulation of the microtubule-associated protein light chain 3B (LC3B) and the expression of the sequestosome-1 (p62/SQSTM). CONCLUSION: Hinokitiol exhibits anti-proliferation activity and has pro-apoptotic effects on OSCC cell lines.

Inhibition of lncRNA RPPH1 activity decreases tumor proliferation and metastasis through down-regulation of inflammation-related oncogenes.

OBJECTIVE: Ribonuclease P RNA component H1 (RPPH1) is a long non-coding RNA (lncRNA) associated with cancer progression. Higher RPPH1 expression in breast and cervical cancer samples than that in normal tissues were observed through the lncRNASNP2 database; therefore, silencing RPPH1 expression might be a potential strategy for cancer treatments, even though RPPH1 is also an RNA subunit of ribonuclease P involved in processing transfer RNA (tRNA) precursors and the effect of RPPH1 knockdown is not yet fully understood. METHODS: Differentially expressed genes (DEGs) were identified through RNA sequencing in each shRNA-transfected RPPH1 knockdown MDA-MB-231, RPPH1 knockdown HeLa cell, and respective control cells, then the gene ontology enrichment analysis was performed by IPA and MetaCore database according to these DEGs, with further in vitro experiments validating the effect of RPPH1 silencing in MDA-MB-231 and HeLa cells. RESULTS: Hundreds of down-regulated DEGs were identified in RPPH1 knockdown MDA-MB-231 and HeLa cells while bioinformatics analysis revealed that these genes were involved in pathways related to immune response and cancerogenesis. Compared to mock- and vector-transfected cells, the production of mature tRNAs, cell proliferation and migration capacity were inhibited in RPPH1-silenced HeLa and MDA-MB-231 cells. Additionally, RPPH1 knockdown promoted G1 cell cycle arrest mainly through the down-regulation of cyclin D1, although glycolytic pathways were only affected in RPPH1 knockdown HeLa cells but not MDA-MB-231 cells. CONCLUSION: This study demonstrated that knockdown RPPH1 affected tRNA production, cell proliferation and metabolism. Our findings might provide insight into the role of RPPH1 in tumor development.

Integrated Medicine for Chemotherapy-Induced Peripheral Neuropathy.

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of typical chemotherapeutics among cancer survivors. Despite the recent progress, the effective prevention and treatment strategies for CIPN remain limited. Better understanding of the pathogenesis of CIPN may provide new niches for developing a new ideal therapeutic strategy. This review summarizes the current understanding of CIPN and current recommendations along with completed/active clinical trials and aims to foster translational research to improve the development of effective strategies for managing CIPN.

The Fibronectin Expression Determines the Distinct Progressions of Malignant Gliomas via Transforming Growth Factor-Beta Pathway.

Due to the increasing incidence of malignant gliomas, particularly glioblastoma multiforme (GBM), a simple and reliable GBM diagnosis is needed to screen early the death-threaten patients. This study aimed to identify a protein that can be used to discriminate GBM from low-grade astrocytoma and elucidate further that it has a functional role during malignant glioma progressions. To identify proteins that display low or no expression in low-grade astrocytoma but elevated levels in GBM, glycoprotein fibronectin (FN) was particularly examined according to the mining of the Human Protein Atlas. Web-based open megadata minings revealed that FN was mainly mutated in the cBio Cancer Genomic Portal but dominantly overexpressed in the ONCOMINE (a cancer microarray database and integrated data-mining platform) in distinct tumor types. Furthermore, numerous different cancer patients with high FN indeed exhibited a poor prognosis in the PrognoScan mining, indicating that FN involves in tumor malignancy. To investigate further the significance of FN expression in glioma progression, tumor specimens from five malignant gliomas with recurrences that received at least two surgeries were enrolled and examined. The immunohistochemical staining showed that FN expression indeed determined the distinct progressions of malignant gliomas. Furthermore, the expression of vimentin (VIM), a mesenchymal protein that is strongly expressed in malignant cancers, was similar to the FN pattern. Moreover, the level of epithelial-mesenchymal transition (EMT) inducer transforming growth factor-beta (TGF-ß) was almost recapitulated with the FN expression. Together, this study identifies a protein FN that can be used to diagnose GBM from low-grade astrocytoma; moreover, its expression functionally determines the malignant glioma progressions via TGF-ß-induced EMT pathway.

The decrease of glycolytic enzyme hexokinase 1 accelerates tumor malignancy via deregulating energy metabolism but sensitizes cancer cells to 2-deoxyglucose inhibition.

Malignant tumors often display an aberrant energy metabolism that relies primarily on glycolysis to produce adenosine triphosphate (ATP) the so-called Warburg effect or aerobic glycolysis. Thus, the elucidation of this energetic alteration in malignant tumors is important in the search for more effective therapeutics against malignant cancers, the most deadly human disease. To investigate whether attenuated glycolytic activity modulates tumor progression, the effects of silencing the first and rate-limiting glycolytic enzyme hexokinase (HK) isozymes HK1 and HK2 were examined. There was an inverse correlation between the expression of HK1 and HK2 in human cancer cells. In cervical carcinoma cells, the HK1 but not HK2 knockdown induced a phenotypic change characteristic of epithelial-mesenchymal transition, which accelerated tumor growth and metastasis both in vitro and in vivo analyses. Notably, the silencing of HK1 disrupted aerobic respiration and increased glycolysis, but it had no effect on ATP generation. These metabolic changes were associated with higher HK2 and lactate dehydrogenase 1 expression but a lower citrate synthase level. Particularly, the HK1 knockdown induced aberrant energy metabolism that was almost recapitulated by HK2 overexpression. Moreover, the HK1-silenced cells showed strong glucose-dependent growth and 2-deoxyglucose (2-DG) induced cell proliferation inhibition. These results clearly indicate that the silencing of HK1, but not HK2, alters energy metabolism and induces an EMT phenotype, which enhances tumor malignancy, but increases the susceptibility of cancer cells to 2-DG inhibition. In addition, this work also suggests that the glycolytic inhibitors should be used only to treat cancers with elevated glycolytic activity.