China
Africa
Explore chapters and articles related to this topic
Oncogenes and Cancer
Published in Pimentel Enrique, Oncogenes, 2020
An alternate method for the appraisal of oncogene activity in human tumors consists in the use of monoclonal antibodies against synthetic peptides corresponding to defined sequences contained in mutant (T24) oncogene protein products. This type of approach has been successfully applied for studying the presence of p21c-ras products in tumor tissue sections of human colon and mammary carcinomas.48 Equal concentrations of p21ras-specific monoclonal antibodies detected the presence of cytoplasmic p21ras products in 97% of 32 human colon carcinomas (vs. none of 5 normal colon samples) and 90% of human mammary carcinomas (vs. 2/21 benign breast lesions). In most of these tumors heterogeneity of p21ras expression was observed at the cellular level, which suggests that continuous expression of c-ras is not necessary for maintenance of the transformed phenotype.
Cancer Risk Assessment II
Published in Peter G. Shields, Cancer Risk Assessment, 2005
The primary genes involved in driving the cancer process are proto-oncogenes and tumor suppressor genes. Proto-oncogenes are important to the regulatory mechanisms of growth, cell cycle, and terminal differentiation. Activation of proto-oncogenes enhances the probability of neoplastic transformation, which can either be an early or late event. Carcinogens can cause mutations in proto-oncogene DNA sequences or they can act as tumor promoters enhancing the activity of oncogene protein products. Examples of a proto-oncogene are those in the RAS family.
Prokinetic effects of Citrus reticulata and Citrus aurantium extract with/without Bupleurum chinense using multistress-induced delayed gastric emptying models
Published in Pharmaceutical Biology, 2023
Yanrong Gong, Xiaoxia Liang, Yanting Dai, Xiang Huang, Qiaozhen Su, Yan Ma, Fenglian Chen, Shuling Wang
The rhythmic peristalsis of gastrointestinal muscle is controlled by specialized gastrointestinal pacemaker cells called interstitial cells of Cajal (ICC) and mediated by some neurotransmitters and hormones (Huizinga 1999). Substance P (SP) is a neuropeptide and as a modulator it plays a pivotal role in gastrointestinal functioning (El-Salhy and Spångéus 1998; Graefe and Mohiuddin 2022). Motilin (MTL) is a gastrointestinal hormone and it is cyclically released during the fasted state by Mo cells in the upper small intestine. In mammals, MTL stimulates appetite and gastrointestinal motility contributing to the movement of undigested food in these regions into the large intestine (Al-Missri and Jialal 2021). In case of disturbed gastrointestinal motility, the release of SP and MTL stimulates c-kit proto-oncogene protein (c-kit) expression in mesenchymal precursor cells and promotes their proliferation and differentiation into ICC. Serotonin (5-HT) is a neurotransmitter and a key molecule linking the nervous system with gastrointestinal function. Peripheral 5-HT activates 5-HT receptor (5-HT4R) in the gastrointestinal tract, thereby initiating the contractility of smooth muscles. As a consequence, ICC pacemaker activity may be generated by the influx of Ca2+ in smooth muscle cells due to gastrointestinal contractility (Huizinga et al. 1995).
Nutritional Indexes as Predictors of Survival and Their Genomic Implications in Gastric Cancer Patients
Published in Nutrition and Cancer, 2021
Yesennia Sánchez, Felipe Vaca-Paniagua, Luis Herrera, Luis Oñate, Roberto Herrera-Goepfert, Guiselle Navarro-Martínez, Dennis Cerrato, Clara Díaz-Velázquez, Ericka Marel Quezada, Claudia García-Cuellar, Diddier Prada
The FBXW7 gene codes for an E3 ubiquitin ligase that targets different oncogene protein products; hence FBXW7 is considered a tumor suppressor gene (29). The loss of this gene has been associated with poor prognosis in gastric cancer patients, as well as poor response to neoadjuvant chemotherapy (30). In the case of TET2, it was mutated in almost 3% of the TCGA cohort (10). These genes, FBXW7 and TET2, have been classified as tumor suppressor genes because of their role in DNA demethylation by methylcytosine oxidation. Their mutations have been mainly reported in myeloid leukemia. In gastric cancer, it has been shown that TET2 inhibits gastric cancer cell growth by upregulating the long non-coding RNA ANRIL and increasing the expression of P15, p16, and p14 proteins (31).
An updated review on exosomes: biosynthesis to clinical applications
Published in Journal of Drug Targeting, 2021
Sheela Modani, Devendrasingh Tomar, Suma Tangirala, Anitha Sriram, Neelesh Kumar Mehra, Rahul Kumar, Dharmendra Kumar Khatri, Pankaj Kumar Singh
In the case of infectious diseases, exosomes convey and express infectious RNA and proteins. These proteins are useful as potential biomarkers in the diagnosis and the detection of active and dormant type of infections within the cell [67]. In cancer, induction of a pro-tumoural microenvironment takes place due to the transfer of mRNA and protein, like mutant Kirsten rat sarcoma viral oncogene protein and c-Met oncoprotein, to other sites by the exosomes. As a result, exosomes play important role in upholding angiogenesis and tumour cell proliferation [68]. Specific expression patterns of serum miRNAs have been reported for lung cancer, colorectal cancer and diabetes, with the proof of serum miRNAs fingerprints for various diseases [69].