Comprehensive analysis of resilience of human airway epithelial barrier against short-term PM2.5 inorganic dust exposure using in vitro microfluidic chip and ex vivo human airway models.

BACKGROUND AND OBJECTIVE: The updated World Health Organization (WHO) air quality guideline recommends an annual mean concentration of fine particulate matter (PM2.5) not exceeding 5 or 15 µg/m3 in the short-term (24 h) for no more than 3-4 days annually. However, more than 90% of the global population is currently exposed to daily concentrations surpassing these limits, especially during extreme weather conditions and due to transboundary dust transport influenced by climate change. Herein, the effect of respirable

EZH2-associated tumor malignancy: A prominent target for cancer treatment.

The discussion in this review centers around the significant relationships between EZH2 and the initiation, progression, metastasis, metabolism, drug resistance, and immune regulation of cancer. Polycomb group (PcG) proteins, which encompass two primary Polycomb repressor complexes (PRC1 and PRC2), have been categorized. PRC2 consists mainly of four subunits, namely EZH2, EED, SUZ12, and RbAp46/48. As the crucial catalytic component within the PRC2 complex, EZH2 plays a pivotal role in controlling a wide range of biological processes. Overexpression/mutations of EZH2 have been detected in a wide variety of tumors. Several mechanisms of EZH regulation have been identified, including regulation EZH2 mRNA by miRNAs, LncRNAs, accessibility to DNA via DNA-binding proteins, post-translational modifications, and transcriptional regulation. EZH2 signaling triggers cancer progression and may intervene with anti-tumor immunity; therefore it has charmed attention as an effective therapeutic target in cancer therapy. Numerouss nucleic acid-based therapies have been used in the modification of EZH2. In addition to gene therapy approaches, pharmaceutical compounds can be used to target the EZH2 signaling pathway in the treatment of cancer. EZH2-associated tumor cells and immune cells enhance the effects of the immune response in a variety of human malignancies. The combination of epigenetic modifying agents, such as anti-EZH2 compounds with immunotherapy, could potentially be efficacious even in the context of immunosuppressive tumors. Summary, understanding the mechanisms underlying resistance to EZH2 inhibitors may facilitate the development of novel drugs to prevent or treat relapse in treated patients.

Correlation between Ubiquitin E3 Ligases (SIAHs) and Heat Shock Protein 90 in Breast Cancer Patients.

Background: Breast cancer is a heterogeneous disease and differences in the expression levels of the ER, PR, and HER2 the triplet of established biomarkers used for clinical decision-making have been reported among breast cancer patients. Furthermore, resistance to anti-estrogen and anti-HER2 therapies emerges in a considerable rate of breast cancer patients, and novel drug therapies are required. Several anomalous signaling pathways have been known in breast cancer have been known; heat shock protein 90 (HSP90) is one of the most plenty proteins in breast cells. The family of ubiquitin ligases such as SIAH1 and SIAH2 is known to specifically target misfolded proteins to the proteasome; also, they have been illustrated to play a role in RAS signaling and as an essential downstream signaling component required for EGFR/HER2 in breast cancer. Methods: The expression of SIAH2, HSP90, and HER2 was assessed by quantitative Real-Time PCR in 85 invasive ductal carcinoma breast tumor samples at Uludag University Hospital in Turkey during the years 2018-2019, and its association with the clinicopathologic variables of patients was evaluated. Results: HSP90, SIAH1, and SIAH2 were significantly (P=0.0271, P=0.022, and P=0.0311) upregulated tumor tissue of patients with breast cancer. Moreover, this study observed a significant association between the high expression of SIAH2/HSP90 with ER status, high expression of HSP90 with Recurrence/Metastasis, and high expression of SIAH2 with Ki-67 proliferation index. Conclusion: The HSP90 and SIAH2 expressions play a significant role in breast cancer development by combining the experimental and clinical data obtained from the literature.

Targeting UPR signaling pathway by dasatinib as a promising therapeutic approach in chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is a myeloproliferative disease that mediated by BCR/ABL oncogenic signaling. CML can be targeted with the imatinib, dasatinib, and nilotinib TKI inhibitors, the latter two of them have been approved for imatinib-resistant or -intolerant CML patients. The TKIs resistance occurs by different molecular mechanisms, including overexpression of BCR-ABL, mutations in the TKI binding site of BCR/ABL, and ER-stress. Unfolded protein responses (UPR) is a cytoprotective mechanism which is activated by ER-stress. The IRE1, PERK, and ATF6 are three main arms of the UPR mechanism and are activated by a common mechanism involving the dissociation of the ER-chaperone BiP/GP78. There is a correlation between ER-stress, CML progression, and response to TKI treatment. In the present study, we aimed to determine alterations of the expression levels of genes related to UPR pathway signaling after treatment with dasatinib in K562 chronic myeloid leukemia cell line by quantitative RT-PCR relatively. The array-data revealed that treatment with dasatinib significantly decreased the UPR mechanism-related genes (including HSPA1B, HSPA2, HSPA4L, ATF6, ATF6B, CEBPB, PERK, TRIB3, DNAJB, ERN1, and UHRF1) in K562 cells. In conclusion, the results showed that dasatinib regulates the UPR mechanism that plays a significant role in cancer progression and therapy resistance in CML. Thus, dasatinib-induced dysfunction of the UPR mechanism may promise encouraging therapy for CML.

The effects of Epigallocatechin-3-gallate and Dabrafenib combination on apoptosis and the genes involved in epigenetic events in anaplastic thyroid cancer cells.

Anaplastic thyroid cancer cases with poor prognosis are associated with epigenetic modifications such as abnormal DNA methylation. Epigallocathesin-3-gallate (EGCG) is a polyphenol compound of green tea that is still under investigation on its role in cancer prevention. EGCG is known as an epigenetic diet in DNA methyltransferase inhibitor. The cytotoxic effects of Dabrafenib, EGCG, and dabrafenib in combination with EGCG were assessed by using WST-8 assay; and also, Flow cytometry was utilized to identify cells undergoing apoptosis after treatments of the SW-1736 cells. We investigated the mRNA expression of genes involved in epigenetic events in SW-1736 cells by real-time qRT-PCR following the treatments. We demonstrated for the first time that the Dabrafenib-EGCG combination reduced cell viability significantly depending on concentration and induced apoptosis by 8.49-fold through investigating the additive effect together on SW-1736 cells. The IC50 doses of Dabrafenib and EGCG for 48 h were determined as 6.7 µM and 22.5 µM, respectively. The results of qRT-PCR demonstrated that the Dabrafenib-EGCG combination significantly caused the down-regulation of genes involved in epigenetic regulation. We suggest that the combination of Dabrafenib and EGCG following in vivo phase studies will contribute as an alternative treatment option for the treatment of ATC.

The expression and prognostic value of miR-146a and miR-155 in Turkish patients with multiple sclerosis.

Multiple sclerosis (MS) is an inflammatory, autoimmune demyelinating, and neurodegenerative disorder of the central nervous system. Interactions between environmental factors, predisposition genes, and determining genes appear to be involved in its etiology. Epigenetic mechanisms such as microRNA-mediated gene regulation can determine the susceptibility and severity of autoimmune diseases. Therefore, to determine the role of miR-146a and miR-155 in MS and its developmental stages, the expression levels in the serum of MS and clinically isolated syndrome (CIS) patients were compared with those of healthy controls. In the present study, the expression levels of miR-146a and miR-155 were assessed using quantitative Real-Time PCR in blood samples of 15 CIS patients and 61 relapsing-remitting multiple sclerosis (RRMS) patients alongside 32 healthy patients as controls. Furthermore, any associations with the clinicopathologic variables of the patients were also evaluated. Dysregulations were found only in the miR-146a and miR-155 expressions in the RRMS-Control group. When the RRMS patients were evaluated in terms of the characteristics of sex, annual attack rate, age of diagnosis, duration of follow-up, and immunomodulatory treatments used, no significant differences were observed. However, significant dysregulations were identified in miRNA expression in the vitamin D level, EDSS values, and the number of attacks. ROC curve analysis showed that miR-146a and miR-155 were significant in the RRMS-Control group for the area under the curve (AUC). It is possible that miR-146a may be associated with vitamin D deficiency and disease disability, while miR-155 may be associated with the number of attacks.

Clinicopathologic features and genetic characteristics of the BRCA1/2 mutation in Turkish breast cancer patients.

The aim of this study was to identify the frequency and spectrum of germline BRCA1/2 pathogenic alterations in a cohort of patients with breast carcinoma. In this study, a total of 603 breast cancer subjects from Turkey were screened for BRCA1/BRCA2 mutations using HDA and Sanger sequencing. In the present study, 21 BRCA1 and BRCA2 pathogenic variants were detected in 30 patients and BRCA1/2 mutations were significantly associated with a family history of breast/ovarian cancer. Analysis of overall survival for BRCA1/BRCA2 mutation carriers showed a trend for poor overall survival only in BRCA1 carriers, although this was not statistically significant in BRCA1 and BRCA2 mutation carriers. The c.5266dupC mutation is one of the most frequently reported mutations in BRCA1 and was identified in five breast cancer patients in our study. The most common BRCA2 gene mutations in the present study were c.8940delA and c.9097dupA, which were found in seven patients. We found mostly BRCA1 and BRCA2 mutation carriers in those patients who showed hormone-positive features. In conclusion, our data showed differences in the distribution of the mutation spectrum of BRCA1 and BRCA2 in Turkey.