Role of Serine/Threonine Kinase 11 (STK11) or liver kinase B1 (LKB1) Gene in Peutz-Jeghers Syndrome

Peutz-Jeghers syndrome (PJS) is a well-described inherited syndrome, characterized by the development of gastrointestinal polyps and characteristic mucocutaneous freckling. PJS is an autosomal prevailing disease, due to genetic mutation on chromosome 19p, manifested by restricted mucocutaneous melanosis in association with gastrointestinal (GI) polyposis. The gene for PJS has recently been shown to be a serine/threonine kinase, known as LKB1 or STK11, which maps to chromosome subband 19p13.3. This gene has a putative coding region of 1302 bp, divided into nine exons, and acts as a tumor suppressor in the hamartomatous polyps of PJS patients and in the other neoplasms that develop in PJS patients. It is probable that these neoplasms develop from hamartomas, but it remains possible that the LKB1 or STK11 locus plays a role in a different genetic pathway of tumor growth in the cancers of PJS patients. This article focuses on the role of LKB1 or STK11 gene expression in PJS and related cancers

Molecular signaling of G‐protein‐coupled receptor in chronic heart failure and associated complications

The well‐known condition of heart failure is a clinical syndrome that results when the myocardium's ability to pump enough blood to meet the body's metabolic needs is impaired. Most of the cardiac activity is maintained by adrenoceptors, are categorized into two main α and β and three distinct subtypes of β receptor: β1‐, β2‐, and β3‐adrenoceptors. The β adrenoreceptor is the main regulatory macro proteins, predominantly available on heart and responsible for down regulatory cardiac signaling. Moreover, the pathological involvement of Angiotensin‐converting enzyme 1 (ACE1)/angiotensin II (Ang II)/angiotensin II type 1 (AT1) axis and beneficial ACE2/Ang (1‐7)/Mas receptor axis also shows protective role via Gi βγ, during heart failure these receptors get desensitized or internalized due to increase in the activity of G‐protein‐coupled receptor kinase 2 (GRK2) and GRK5, responsible for phosphorylation of G‐protein‐mediated down regulatory signaling. Here, we investigate the various clinical and preclinical data that exhibit the molecular mechanism of upset level of GRK change the cardiac activity during failing heart.<br/