Luminal breast cancer subtypes respond poorly to endocrine and trastuzumab treatments due to cellular heterogeneity arising from the phenotype transitions, accounted for mainly by the loss of receptor expression. The origins of basal-like and human epidermal growth factor receptor 2 (HER2)-overexpressing breast cancer subtypes have been attributed to genetic and protein modifications in stem-like cells and luminal progenitor cell populations, respectively. The post-transcriptional regulation of protein expression is known to be influenced by microRNAs (miRNAs) that are deemed to be master regulators of several biological processes in breast tumorigenesis and progression. Our objective was to identify the fractions of luminal breast cancer cells that share stemness potentials and marker profiles and to elucidate the molecular regulatory mechanism that drives transitions between fractions, leading to receptor discordances. Established breast cancer cell lines of all prominent subtypes were screened for the expression of putative cancer stem cell (CSC) markers and drug transporter proteins using a side population (SP) assay. Flow-cytometry-sorted fractions of luminal cancer cells implanted in immunocompromised mice generated a pre-clinical estrogen receptor alpha (ERα+) animal model with multiple tumorigenic fractions displaying differential expression of drug transporters and hormone receptors. Despite an abundance of estrogen receptor 1 (ESR1) gene transcripts, few fractions transitioned to the triple-negative breast cancer (TNBC) phenotype with a visible loss of ER protein expression and a distinct microRNA expression profile that is reportedly enriched in breast CSCs. The translation of this study has the potential to provide novel therapeutic miRNA-based targets to counter the dreaded subtype transitions and the failure of antihormonal therapies in the luminal breast cancer subtype.

Here, we report the complete sequence of four influenza A(H1N1) virus samples isolated from cases that occurred during the 2017 epidemic season in Kerala in South India. Sequence analysis showed mutations that differentiate this strain from the reference strain A/California/07/2009 virus.

Quantitative determination of neutralizing antibodies against Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2) is paramount in immunodiagnostics, vaccine efficacy testing, and immune response profiling among the vaccinated population. Cost-effective, rapid, easy-to-perform assays are essential to support the vaccine development process and immunosurveillance studies. We describe a bead-based screening assay for S1-neutralization using recombinant fluorescent proteins of hACE2 and SARS-CoV2-S1, immobilized on solid beads employing nanobodies/metal-affinity tags. Nanobody-mediated capture of SARS-CoV-2-Spike (S1) on agarose beads served as the trap for soluble recombinant ACE2-GFPSpark, inhibited by neutralizing antibody. The first approach demonstrates single-color fluorescent imaging of ACE2-GFPSpark binding to His-tagged S1-Receptor Binding Domain (RBD-His) immobilized beads. The second approach is dual-color imaging of soluble ACE2-GFPSpark to S1-Orange Fluorescent Protein (S1-OFPSpark) beads. Both methods showed a good correlation with the gold standard pseudovirion assay and can be adapted to any fluorescent platforms for screening.

Background Diabetic foot ulcer (DFU) is a severe complication of diabetes mellitus (DM), contributing significantly to morbidity and healthcare burden. Kerala, a South Indian state, has a high prevalence of diabetes, yet limited data exist on the genetic risk factors for DFU in this population. Vitamin D, beyond its role in calcium homeostasis, is crucial for immune regulation and wound healing. Methods In this study, plasma vitamin D levels were evaluated in individuals with DFU (n=112), DM without ulcers (n=112), and non-diabetic controls (n=112). We also assessed the association of four common vitamin D receptor (VDR) gene polymorphisms—rs7975232 (ApaI), rs731236 (TaqI), rs1544410 (BsmI), and rs2228570 (FokI)—with DFU and DM. Results The arithmetic mean 25(OH)D levels were 17.7 ± 14.2 ng/mL (DFU), 19.5 ± 12.4 ng/mL (DM), and 20.6 ± 13.9 ng/mL (controls). Geometric means were lower across all groups, with 12.7 ng/mL (DFU), 15.4 ng/mL (DM), and 15.7 ng/mL (controls), indicating widespread vitamin D deficiency, especially in DFU cases. Among the SNPs studied, rs731236 and rs1544410 showed statistically significant associations with DFU. The AG genotype of rs731236 was significantly associated with a reduced risk of DFU compared to both DM patients and non-diabetic controls (p < 0.05, OR ≈ 0.5), indicating a strong protective effect. Similarly, the TC genotype of rs1544410 showed a protective association against DFU (p = 0.0219, OR = 0.51). In contrast, the AA genotype of rs731236 and TT genotype of rs1544410 were marginally associated with increased DFU risk. No significant associations were found for rs2228570 and rs7975232. However, the ff genotype of rs2228570, which is associated with a less active VDR protein, was predominantly observed among study participants. VDR polymorphisms, especially rs731236 and rs1544410, may significantly influence DFU susceptibility in the Kerala population and hold promise as genetic risk markers. Routine vitamin D screening could aid early risk assessment in diabetic individuals.