ABSTRACT The purpose of the study is mainly to investigate anti proliferation of non-small cell lung cancer A549 cells and its mechanism by inhibition of CHK1 expression combined with gemcitabine. The mRNA and protein levels of genes were analyzed by RT-qPCR and Western blot, respectively. Cell viability was detected by CCK-8 assay and clone formation assay. The detection of the cell cycle was used by Annexin V/7-amino-actinomycin D apoptosis detection kit. Analysis of DNA damage was done by immunofluorescence and alkaline comet assay. The results showed that inhibition of CHK1 and gemcitabine combination significantly reduced the proliferation ability of the two cell lines. We also revealed the degradation of full-length PARP and reduced Bcl-2/Bax ratio on increased apoptosis. Inhibition of CHK1 expression leads to DNA damage, induces phosphorylation of γ-H2AX, and affects the repair of homologous recombination ability through Rad51. Mechanistically, gemcitabine increased phosphorylation-ATR and phosphorylation-CHK1, indicating activation of the DNA repair system and ATR-CHK1-CDC25A pathway. Inhibition of CHK1 resulted in increased synthesis of CDK2/Cyclin A2 and CDK2/Cyclin E1 complexes, and more cells entered the subsequent cell cycle, leading to S phase arrest and mitotic catastrophe. We identified inhibition of CHK1 as a potential treatment for NSCLC and confirmed that inhibition of this kinase could overcome acquired gemcitabine resistance.

ABSTRACT Cervical cancer (CC) is one of the common malignant tumors in women, and the incidence rate is located in the second place of female tumors. As a major RNA N6-methyladenosine (m6A) methyltransferase, methyltransferase-like 14 (METTL14) is involved in tumor progression by catalyzing methylation modifications in mRNAs. However, the molecular mechanism of METTL14-mediated m6A modification in CC remains not fully revealed. The expression of METTL14 was detected by RT-qPCR and western blot. Cell function was assayed by cell counting kit-8 (CCK-8) assay and flow cytometry analysis. Methylated RNA immunoprecipitation (MeRIP) was used to confirm the relationship between METTL14 and homeobox B13 (HOXB13). In our study, we found that the level of METTL14 was elevated in CC tissues and cells compared with their controls. The inhibition of METTL14 significantly impaired cell proliferation and the epithelial-mesenchymal transition (EMT) process, while also induced apoptosis in HeLa and C33A cells. Furthermore, our findings indicated that homeobox B13 (HOXB13) was a target of METTL14, which positively regulated the expression of HOXB13 in an m6A-dependent manner. Rescue experiments indicated that overexpression of HOXB13 effectively reversed the tumor suppression induced by METTL14 knockdown. Finally, we confirmed that METTL14-modified HOXB13 exerted an oncogenic effect through activation of the nuclear factor kappa B (NF-κB) pathway. In conclusion, our data demonstrated that the m6A modification of HOXB13, mediated by METTL14, facilitated the advancement of CC through targeting the NF-κB pathway, which may be a potential molecular target for the treatment of CC.

ABSTRACT The nucleolar enzyme sirtuin 7 (SIRT7) promotes cancer progression in certain malignancies, likely in part by controlling ribosome biosynthesis. Recently, we discovered that SIRT7 destabilizes the cyclin dependent kinase inhibitor 2A (CDKN2A, known as ARF) within the nucleolus, aiding cancer progression. We propose that targeting nucleolar SIRT7 offers promise for new anti-cancer therapies.

ABSTRACT Clemastine is an antagonist of histamine H1 receptor may provide benefits in the treatment of osteosarcoma (OS). In the current study, we used hyperthermia approach to sensitize OS cells to clemastine-mediated cell death. Osteosarcoma U-2 OS and Saos-2 cells were treated with clemastine at 37°C, followed by 42°C for 2 h, and released at 37°C for 6 h. The impact of clemastine and hyperthermia on OS cell survival and autophagy-mediated cell death was investigated. Exposure of U-2 OS and Saos-2 cells to clemastine and hyperthermia (42°C) inhibited dose-dependent clemastine-mediated cell survival by increasing cell apoptosis. Hyperthermia and clemastine exposure modulated inflammatory and unfolded protein response (UPR) signaling differentially in U-2 OS and Saos-2 cells. Exposure of U-2 OS and Saos-2 cells to hyperthermia and clemastine inhibited AKT/mTOR and induced expression of the autophagy biomarkers LC3B II and LC3-positive puncta formation. The inhibition of autophagy by 3-methyladenine blocked hyperthermia and clemastine-mediated induction of LC3B II, LC3-positive puncta formation, and OS cell apoptosis. These results indicate that clemastine and hyperthermia sensitize OS cell lines by inducing increased autophagic cell death. Collectively, our data suggest that hyperthermia along with antihistamine therapy may provide an improved approach for the treatment of OS.

ABSTRACT Cisplatin is the commonly used chemotherapeutic drug in treatment of various cancers. However, development of resistance towards cisplatin results in tumor recurrence. Here, we aim to understand the mechanisms of action of cisplatin and emergence of resistance to cisplatin using mass spectrometry-based proteomic approach. A panel of head and neck squamous cell carcinoma (HNSCC) cell lines were treated with cisplatin at respective IC50 for 24 h and label-free mass spectrometry analysis was carried out. Proteomic analysis of A253, FaDu, Det562 and CAL27 cell lines upon cisplatin treatment resulted in the identification of 5,060, 4,816, 4,537 and 4,142 proteins, respectively. Bioinformatics analysis of differentially regulated proteins revealed proteins implicated in DNA damage bypass pathway, translation and mRNA splicing to be enriched. Further, proteins associated with cisplatin resistance exhibited alterations following short-term cisplatin exposure. Among these, class III tubullin protein (TUBB3) was found to be upregulated in cisplatin-treated cells compared to untreated cells. Western blot analysis confirmed the elevated expression of TUBB3 in cells treated with cisplatin for 24 h, and also in cisplatin resistant HNSCC cell lines. This study delineates the early signaling events that enable HNSCC cells to counteract the cytotoxic effects of cisplatin and facilitate the development of resistance.

ABSTRACT Identification of dominant, actionable oncogenic signaling pathways is key to guide the development of new targeted treatments for advanced-stage hepatocellular carcinoma (HCC). We have recently unveiled a novel YES-YAP/TAZ signaling axis involved in liver cancer development. Our study identifies the tyrosine kinase YES as a potential therapeutic target in HCC.

ABSTRACT Phenolic compounds derived from olive oil have beneficial health properties against cancer, neurodegenerative, and metabolic diseases. Therefore, there are discrepancies in their impact on mitochondrial function that result in changes in oxidative capacity, mitochondrial respiration, and energetic demands. This review focuses on the versatile role of oleuropein, a potent antioxidant that regulates the AMPK/SIRT1/mTOR pathway to modulate autophagy/mitophagy and maintain metabolic homeostasis.

ABSTRACT Our recent study revealed that APOBEC3B is upregulated during the preinvasive stages of non-small cell lung cancer and breast cancer. In addition to its role in mediating single nucleotide variants, we propose that APOBEC3 promotes copy number intratumor heterogeneity prior to invasion, providing a substrate for cancer evolution.

ABSTRACT In vivo modeling combined with CRISPR/Cas9-mediated somatic genome editing has contributed to elucidating the functional importance of specific genetic alterations in human tumors. Our recent work uncovered tumor suppressor pathways that affect EGFR-driven lung tumor growth and sensitivity to tyrosine kinase inhibitors and reflect the mutational landscape and treatment outcomes in the human disease.

ABSTRACT The protein-lipid complex alpha1-oleate, derived from HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells), is identified as a molecular entity with significant therapeutic potential. Structural characterization of the complex and results of a successful placebo-controlled clinical trial are presented.