Epidemiological and molecular evaluation of BRAF, KRAS, NRAS genes and MSI in the development of colorectal cancer.

Background And Objectives: KRAS, NRAS, BRAF mutations and microsatellite instability (MSI) can be associated with Colorectal Cancer (CRC) development.

Material And Methods: We evaluated 828 medical records of CRC patients from a school hospital from January/2016 to December/2020. Variables such as age, gender, ethnicity, literacy level, smoking, alcoholism, primary anatomical site, tumor staging, presence of BRAFV600E, KRAS, NRAS mutations and MSI , survival and metastasis were identified.

Anti-EGFR treatment effects on laryngeal cancer stem cells.

Laryngeal cancer (LC) is one of the common head and neck neoplasms and is characterized by resistance to conventional therapy and poor prognosis. This may result from the presence of cancer stem cells (CSCs), which form a small population in tumors with metastatic potential, high invasive capacity, self-renewal, and differentiation. This study aimed to evaluate the effectiveness of 5-fluorouracil and cisplatin individually, as well as the combination of cetuximab and paclitaxel in a CSC subpopulation separated with biomarkers related to tumoral growth (CD44, CD117, and CD133).

Gene Polymorphisms Involved in Folate Metabolism and DNA Methylation with the Risk of Head and Neck Cancer.

Background: Folate is essential for DNA synthesis, repair, and methylation. Polymorphisms in genes associated with folate metabolism may alter these processes and, consequently, modulate cancer development.

Aim: We aimed to assess DNMT3B -149C/T (rs2424913), DNMT3B -283T/C (rs6087990), DNMT3B -579G/T (rs2424909), DHFR 19-pb ins/del (rs70991108), SHMT1 1420C/T (rs1979277), and TYMS 28-bp tandem repeat (rs34743033) polymorphisms with risk of head and neck cancer.

Role of Tropomyosin-related kinase B receptor and brain-derived neurotrophic factor in cancer.

The tropomyosin-related kinase B (TrkB) receptor is a member of the neurotrophic tyrosine kinase receptors family and, together with the brain-derived neurotrophic factor (BDNF), plays an important role in the development of breast cancer, lung cancer, neuroblastoma, colorectal cancer, leukemia, cervical cancer, gallbladder cancer, gastric cancer, kidney cancer, Ewing's sarcoma, esophageal cancer, and head and neck cancer. Overexpression of these two factors has been associated with increased processes involved in carcinogenesis, such as invasion, migration, epithelial-mesenchymal transition (EMT), angiogenesis, metastasis, cell proliferation, resistance to apoptosis, resistance to cell death due to loss of adhesion (anoikis), activation of cell proliferation pathways, regulation of tumor suppressor genes, and drug resistance, and is related to advanced clinical stage. Inhibition of the TrkB/BDNF axis using drugs in phase 1 studies, approved drugs, and small interfering RNA (siRNA) are promising strategies for the treatment of various malignant tumors in addition to increasing the sensitivity of cells resistant to chemotherapy, improving the effectiveness of drugs without increasing toxicity.

Glutathione S-transferase Polymorphisms in Head and Neck Squamous Cell Carcinoma Treated with Chemotherapy and/or Radiotherapy.

Background/aim: The Glutathione S-transferases (GSTs) are important carcinogen-metabolizing enzymes. Polymorphisms involved in these enzymes can modulate the development and treatment of head and neck cancer. To investigate the association of GSTs polymorphisms with head and neck cancer and risk factors, clinical-pathological features, and survival time of the patients treated with chemotherapy and/or radiotherapy.

Characterization and strong risk association of to polymorphism and and their influence on mRNA expression in gastric cancer.

Background: Toll-like receptor-2 () is responsible for recognizing () and activating the immune response. Polymorphisms in may modulate gastric carcinogenesis.

Aim: To evaluate whether the (rs3804099) and - (rs111200466) polymorphisms contribute to gastric carcinogenesis in the Brazilian population, and to determine the influence of both polymorphisms and infection on mRNA expression.

Toll-like receptor 9 polymorphisms and influence gene expression and risk of gastric carcinogenesis in the Brazilian population.

Background: Toll-like receptors (TLRs) are the first line of host defense, and are involved in () recognition and activation of both inflammatory and carcinogenic processes. The presence of single nucleotide polymorphisms (SNPs) in genes that activate the immune response may modulate the risk of precancerous lesions and gastric cancer (GC). Among them, Toll-like receptor 9 (TLR9) polymorphisms have emerged with a risk factor of infectious diseases and cancer, however the studies are still inconclusive.