Leptin is a protein hormone, mainly synthesized in adipocytes, that regulates the food intake and energy expenditure of the body. Rare mutations in the leptin gene cause obesity. Common polymorphisms of the leptin gene have been associated with obesity, however their association with arterial blood pressure has not been fully elucidated. The aim of the present study was to examine the effect of variants in the 3′ flanking region of the leptin gene on blood pressure in hypertensive subjects with high (35.2±5.12) and low (20.13±1.3) body mass index (BMI). Microsatellite polymorphisms and the C538T SNP in the 3′UTR of the leptin gene were screened in 362 subjects, and different biochemical and anthropometric parameters were measured. The levels of serum urea, creatinine, glucose, cholesterol, triglyceride, leptin and angiotensin II were determined in all subjects. A strong association of microsatellite polymorphisms with essential hypertension was found in subjects with a high BMI, but this association was only slight in subjects with a normal BMI. The C538T variant was not found in this population. The frequency of the Class I/Class I and Class I/Class II genotype for tetranucleotide polymorphisms was also significantly higher in the hypertensive compared to the normotensive group (p≤0.0001). In addition, a significant correlation was found between serum leptin and Class I/I and Class I/II genotypes. Linear regression analysis showed an independent correlation of leptinemia with BMI (p=0.019), while a notable correlation was found between serum leptin concentration and angiotensin II. The study confirmed that shorter alleles of microsatellites in the 3′ flanking region of leptin are significantly associated with hypertension, however, the underlying mechanism remains unknown.

<b><i>Introduction:</i></b> Diffuse large B-cell lymphoma (DLBCL) is the most prevalent subtype of non-Hodgkin’s lymphoma (NHL) accounting for 30% of adult NHL worldwide and 50% in developing countries like India. DNA damage and Myc-induced transformation are well-known contributing factors towards development of DLBCL. A recently identified HSP90 co-chaperone complex R2TP has been shown to contribute towards DNA damage and Myc-induced transformation. This study aimed to analyse the immunohistochemical (IHC) expression of R2TP complex components RUVBL1, PIH1D1, and RPAP3 in DLBCL patients and correlate with prognosis. <b><i>Methods:</i></b> DLBCL (<i>n</i> = 54) histological slides were retrieved from archives, and detailed histomorphological and clinical features were noted. IHC staining of R2TP complex components RUVBL1, PIH1D1, and RPAP3 was performed on 54 cases (FFPE) of DLBCL. Expression data were correlated with survival and clinical features. <b><i>Results:</i></b> Out of the 54 DLBCL cases, 59.26% (<i>n</i> = 32) stained positive for RUVBL1. The RUVBL1 expression was associated with poor prognosis in both progression-free survival (PFS) (<i>p = 0.0146</i>) and overall survival (OS) (<i>p = 0.0328</i>). The expression was positively correlated with bone marrow involvement (<i>p = 0.0525</i>). The expression of PIH1D1 was observed in 68.51% (<i>n</i> = 32) of DLBCL cases, and positive correlation was observed with international prognostic index score (<i>p = 0.0246</i>); however, no correlation was observed with PFS or OS. Finally, RPAP3 was found immunopositive in only 1 case of DLBCL. <b><i>Conclusions:</i></b> Immunopositivity for RUVBL1 is associated with poor prognosis along with a higher relapse rate amongst the DLBCL patients. PIH1D1 immunopositivity correlated with a higher IPI score.

The R2TP complex which comprises of RUVBL1, RUVBL2, PIH1D1 and RPAP3 in humans is known to be a specialized Co-chaperone of Hsp-90 protein. This multimeric-protein complex is involved in the assembly and maturation of several multi-subunit complexes including RNA polymerase II, small nucleolar ribonucleoproteins, and complexes containing phosphatidylinositol-3-kinase-like kinases. Since their discovery as a co-chaperone of Hsp90, the R2TP complex is involved in multitude of cellular processes including, chromatin remodelling, transcription regulation, ribonucleoprotein complex biogenesis, mitotic assembly, telomerase complex assembly, and apoptosis. Lymphoma arises from the abnormal proliferation of B-cells and the R2TP complex have been reported to play an important role in the activation of p53 and RB. Therefore, the inactivation in any of the tumor suppressor pathways can drive cells to malignancy.However, there are multiple factors which may contribute towards malignancy but the folding defects in these tumor suppressor pathways could be one of the reasons. R2TP is tightly linked with oncogenesis and its inhibition can decrease the proliferation activity of cancer cells. So, the multisubunit chaperone complex as well as its components could be promising candidates for cancer chemotherapy.