👤 Nazia Pathan

Familial hypobetalipoproteinemia is a rare autosomal codominant disorder, often caused by a defect in apolipoprotein B (apoB) production required for lipoprotein formation and secretion. Characterization of the lipid profiles of 3 family members exhibiting very low circulating cholesterol levels. Plasma samples from the control sibling and the affected patients were analyzed. Fast protein liquid chromatography and high-performance liquid chromatography were used to characterize the lipid profiles, size, and distribution of lipoprotein particles. Exome sequencing of family members revealed a single-nucleotide deletion in APOB in the 3 affected individuals. The effect of the single-nucleotide deletion on the secretion of apoB was analyzed in Immortalized Human Hepatocyte (IHH) cells. Plasma lipid profiles revealed that the affected individuals have low levels of total cholesterol and low-density lipoprotein cholesterol, with no difference in lipoprotein particle size. DNA sequencing of APOB revealed a single heterozygote deletion of an adenosine in exon 3 at the nucleotide position 1268 in all affected members. This deletion introduces a reading frame shift at glutamine 380, resulting in a stop codon at position 397. The C-terminally truncated apoB, called apoB9, is a variant spanning ∼9% of the full-length protein. Upon expression of apoB9 in IHH cells, the protein did not exit the endoplasmic reticulum/cis-Golgi and, hence, was not secreted into the media. Molecular modeling revealed that apoB9 lacks the βA- and βB-sheets that are required for lipid particle formation, which can explain the absence of apoB9 secretion. Our data suggested that the affected family members have ∼50% to 60% lower apoB levels and are likely protected against the development of atherosclerosis and cardiovascular diseases. Show less

Pancreatic ductal adenocarcinoma (PDA) is an aggressive malignancy that lacks reliable biomarkers to guide treatment decisions. Effective prognostic tools are needed to improve its clinical management. We conducted a comprehensive proteomic analysis on 115 PDA patient samples with matched adjacent normal tissue. A 20-protein diagnostic panel was identified (LGALS1, ANXA2, LGALS3BP, CTSD, S100P, COL12A1, SFN, THBS2, CTHRC1, THBS1, SERPINB5, LAMC2, POSTN, CEACAM6, CTSE, PLEC, PKM, S100A11, TAGLN2, ALDOA). Consensus clustering analysis identified four prognostic proteomic subtypes. Subtypes with poorer prognoses exhibited upregulation of neutrophil degranulation, extracellular matrix remodeling, focal adhesion, Mesenchymal Epithelial Transition, collagen formation, and PI3K-Akt-mTOR-related pathways, indicating a predominance of basal-like and activated stromal features. In tumors with homologous recombination deficiency or Catalogue of Somatic Mutations in Cancer Signature-3, several immune-related proteins were enriched. An 18-protein (PURB, SDCBP2, CD2BP2, GALM, SERPINA3, OAS3, FAN1, ZPR1, KRT2, NUDT2, SMNDC1, SERPINA4, CUTA, WDR36, POSTN, CLEC11A, PEX14, and PI4KA) risk score was developed and validated using multicox regression analyses with LASSO regularization. The risk score demonstrated independent prognostic significance for overall survival and recurrence, and was validated in an independent proteomic dataset generated using a different proteomic technology. This study thus introduces four novel prognostic PDA subtypes, and an 18-protein risk score validated in an independent dataset, which shows promise for improving survival prediction and could serve as a valuable tool for personalized treatment guidance. The findings from this study have significant implications for the future of pancreatic cancer management. By identifying a 20-protein panel with diagnostic and screening potential, this research provides a foundation for developing early detection tools for PDA, an aggressive cancer with limited treatment options. The classification of PDA into four proteomic subtypes with distinct prognostic outcomes paves the way for subtype-specific therapeutic approaches, allowing clinicians to better stratify patients based on their risk profiles. Additionally, the validated 18-protein risk score, which enhances survival prediction and operates independently of existing clinical variables, represents a promising tool for personalized prognostic assessments. Incorporating these proteomic-based biomarkers into clinical practice could improve diagnostic accuracy, guide individualized treatment decisions, and ultimately enhance patient outcomes in PDA. This study underscores the potential of proteomic profiling to improve cancer treatment by providing targeted, actionable insights into tumor biology. Show less

Colorectal cancer is a major health concern as it ranks third in incidence and second major cause of cancer-related deaths worldwide. A leading cause of treatment failure has been attributed to cancer stem cells that can invariably resist existing chemotherapeutic regimens. Notch signaling pathway has been involved in the maintenance of stem cells besides being crucial in cell fate decision and embryonic development. This pathway has also been implicated in several human malignancies including colorectal cancer. We investigated mRNA expression of four Notch receptors (Notch1-4), five ligands (Jag1, Jag2, Dll1, Dll3, and Dll4), and four target genes (Hes1, Hes5, Hey1, and Hey2) using highly specific TaqMan gene expression assays in colorectal adenomas and cancers. Upregulated expression of Notch receptors ranged between 29 and 73% in colorectal cancers and between 11 and 56% in adenomas. Expression of Notch3 and Notch4 receptors was significantly higher in colorectal cancers compared to normal and adenoma tissues. The Jagged and Delta-like ligands were overexpressed between 25 and 52% in colorectal cancers, while in adenomas, it ranged between 0 and 33%. Combining the data for upregulation of receptors and ligands suggests that 86% colorectal cancers and 56% adenomas exhibited overexpression of Notch pathway genes in our cohort. Notch target genes were upregulated between 24 and 33% in colorectal cancers and between 11 and 22% in adenomas. Collating upregulation of Notch receptors and ligands with the target genes showed concordance in 58% colorectal tumors. Additionally, we evaluated expression of Notch receptors, ligands, and target genes with prognosis using the TCGA mRNA expression dataset. Patients overexpressing Notch3, Notch4, and Hey1 had significantly poorer overall survival relative to those having lower levels of these genes. Taken together, Notch signaling components are aberrantly overexpressed in colorectal tumors, and development of therapeutics targeting the Notch pathway may prove to be beneficial in the management of colorectal cancers. Show less