Non-Receptor Tyrosine Kinases: Their Structure and Mechanistic Role in Tumor Progression and Resistance.

Protein tyrosine kinases (PTKs) function as key molecules in the signaling pathways in addition to their impact as a therapeutic target for the treatment of many human diseases, including cancer. PTKs are characterized by their ability to phosphorylate serine, threonine, or tyrosine residues and can thereby rapidly and reversibly alter the function of their protein substrates in the form of significant changes in protein confirmation and affinity for their interaction with protein partners to drive cellular functions under normal and pathological conditions. PTKs are classified into two groups: one of which represents tyrosine kinases, while the other one includes the members of the serine/threonine kinases. The group of tyrosine kinases is subdivided into subgroups: one of them includes the member of receptor tyrosine kinases (RTKs), while the other subgroup includes the member of non-receptor tyrosine kinases (NRTKs). Both these kinase groups function as an "on" or "off" switch in many cellular functions. NRTKs are enzymes which are overexpressed and activated in many cancer types and regulate variable cellular functions in response to extracellular signaling-dependent mechanisms. NRTK-mediated different cellular functions are regulated by kinase-dependent and kinase-independent mechanisms either in the cytoplasm or in the nucleus. Thus, targeting NRTKs is of great interest to improve the treatment strategy of different tumor types. This review deals with the structure and mechanistic role of NRTKs in tumor progression and resistance and their importance as therapeutic targets in tumor therapy.

A systematic review of contemporary evidence on SARS-CoV-2 and HIV coinfection: What does it look like up to date?

BACKGROUND: Preexisting alteration of the immune system by factors including older age, cardiovascular diseases, morbid obesity, diabetes, and chronic obstructive pulmonary disease (COPD) have detrimental effects on SARS-CoV-2 patients. Literature regarding SARS-CoV-2/human immunodeficiency virus (HIV) is still developing. MATERIALS AND METHODS: We reviewed the existing literature pertaining to SARS-CoV-2/HIV coinfection systematically. Research records' characteristics and patients' clinical data were collected. RESULTS: Seven research records were included, of which three were case series and four were case reports, reporting a total of 16 cases. There was one case of death, whereas (15/16) patients were discharged home. Majority of patients developed consistent clinical presentation of SARS-CoV-2. All patients had initial positive RT-PCR results, and four cases had HIV-related lymphopenia. CONCLUSION: Although the current literature is still growing to increase our understanding of SARS-CoV-2/HIV coinfection, people living with HIV should adhere to the guidelines of healthy behavior and practice during this pandemic.