Sam68 is Overexpressed in Epithelial Ovarian Cancer and Promotes Tumor Cell Proliferation

Antibody-based biosensor to detect oncogenic splicing factor Sam68 for the diagnosis of lung cancer

OBJECTIVE

The present work aimed to investigate the potential utility of Sam68 protein as a prognostic marker in lung cancer. Then an electrochemical immunosensor is fabricated that is sufficiently sensitive to detect Sam68.

RESULTS

Analysis of stage-specific Lung cancer microarray data shows that differential expression of Sam68 is associated with cancer stage and monotonically increases from early tumor stage to advanced metastatic stage. Moreover, the higher expression of Sam68 results in reduced survival of lung cancer patients. Based on these observations, an electrochemical immunosensor was developed for the quantification of Sam68 protein. The target protein was captured by the Anti-Sam68 antibody that was immobilized on the modified Glassy carbon electrode. The stepwise assembly process was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. This fabricated immunosensor displayed good analytical performance in comparison to commercial ELISA kit with good sensitivity, lower detection limit (LOD) of 10.5 pg mL^-1, and wide linear detection range from 1 to 5 μg mL^-1. This method was validated with satisfactory detection of Sam68 protein in lung adenocarcinoma cell line, NCI-H23. Besides, spike and recovery assay reconfirm that the sensor can precisely quantify Sam68 protein in a complex physiological sample.

CONCLUSION

We conclude Sam68 as a valuable prognostic biomarker for early detection of lung cancer. Moreover, we report the first study on the development of an electrochemical immunosensor for the detection of Sam68. The fabricated immunosensor exhibit excellent analytical performance, which can accurately predict the lung cancer patient pathological state.

Splicing Machinery is Dysregulated in Pituitary Neuroendocrine Tumors and is Associated with Aggressiveness Features

Pituitary neuroendocrine tumors (PitNETs) constitute approximately 15% of all brain tumors, and most have a sporadic origin. Recent studies suggest that altered alternative splicing and, consequently, appearance of aberrant splicing variants, is a common feature of most tumor pathologies. Moreover, spliceosome is considered an attractive therapeutic target in tumor pathologies, and the inhibition of SF3B1 (e.g., using pladienolide-B) has been shown to exert antitumor effects. Therefore, we aimed to analyze the expression levels of selected splicing-machinery components in 261 PitNETs (somatotropinomas/non-functioning PitNETS/corticotropinomas/prolactinomas) and evaluated the direct effects of pladienolide-B in cell proliferation/viability/hormone secretion in human PitNETs cell cultures and pituitary cell lines (AtT-20/GH3). Results revealed a severe dysregulation of splicing-machinery components in all the PitNET subtypes compared to normal pituitaries and a unique fingerprint of splicing-machinery components that accurately discriminate between normal and tumor tissue in each PitNET subtype. Moreover, expression of specific components was associated with key clinical parameters. Interestingly, certain components were commonly dysregulated throughout all PitNET subtypes. Finally, pladienolide-B reduced cell proliferation/viability/hormone secretion in PitNET cell cultures and cell lines. Altogether, our data demonstrate a drastic dysregulation of the splicing-machinery in PitNETs that might be associated to their tumorigenesis, paving the way to explore the use of specific splicing-machinery components as novel diagnostic/prognostic and therapeutic targets in PitNETs.

Upregulation of KIF26B, Cell Migration and Proliferation of Human Ovarian Cancer Cell Lines In Vitro, and Patient Outcomes from Human Bioinformatic Analysis

Background

The aim of this study was to assess the expression profile of the KIF26B gene, its effects on ovarian cancer cell behavior in vitro, the clinical prognostic value of expression of the KIF26B gene and associated signaling pathways, from bioinformatics data analysis.

Material/Methods

The Cancer Genome Atlas-Ovarian Cancer (TCGA-OV) database and the online Kaplan-Meier plotter for ovarian cancer were analyzed. Human ovarian cancer cell lines A2780 and SKOV3 were used to study the in vitro effects of KIF26B gene expression on cell proliferation and cell invasion. Genes that interacted with, co-localized to, and were co-expressed with the KIF26B gene (Pearson’s r ≥0.6) were identified and underwent Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis.

Results

Increased expression of the KIF26B gene increased the proliferation and migration of A2780 and SKOV3 cells in vitro. KIF26B protein expression was upregulated in ovarian cancer tissue and was associated with lymphatic and venous invasion. TCGA-OV data analysis showed that increased expression of the KIF26B gene was significantly associated with reduced 3-year, 5-year, and 10-year overall survival (OS), progression-free survival (PFS), and post-progression survival (PPS). The genes that interacted with, co-localized to, and were co-expressed with KIF26B were enriched in several KEGG pathways; upregulation of the KIF26B gene was associated with TGF-β signaling pathway.

Conclusions

Upregulation of KIF26B enhanced proliferation and migration of ovarian cancer cells in vitro. Bioinformatics analysis supported the association between increased expression of the KIF26B gene and reduced clinical outcome in patients with ovarian carcinoma.

Alginate Particles with Ovalbumin (OVA) Peptide Can Serve as a Carrier and Adjuvant for Immune Therapy in B16-OVA Cancer Model

BACKGROUND Alginate is a natural polysaccharide obtained from brown algae and has been shown to have numerous applications in biomedical science, such as wound healing, delivery of bioactive agents, and cell transplantation. Ovalbumin (OVA) peptide 323-339 has been reported to be involved in immune response.  MATERIAL AND METHODS This work investigated the use of alginate particles as a carrier and adjuvant for the immune therapy of cancer. Alginate particles loaded with OVA peptide were produced via emulsion. A tumor model was established in C57BL/6J mice via subcutaneous injection of 3×105 B16-OVA tumor cells. The effect of alginate/OVA peptide on cell viability was analyzed by use of the CCK-8 assay kit. Activation of macrophages was examined by checking cell surface makers CD40 and CD86 by FACs. RESULTS Alginate/OVA peptide inhibited tumor progression more effectively than using the peptide alone. The viability and uptake study illustrated that this particle is safe and non-toxic. The activation study demonstrated that alginate particles can promote the activation of surface markers on macrophages. ELISA assay showed that the particles with peptide can promote the secretion of inflammatory and effector cytokines from macrophages.  CONCLUSIONS This study demonstrated that alginate has dual functions in immune therapy of cancer, serving both as a carrier and an adjuvant.

RNA-Binding Proteins in Female Reproductive Pathologies

RNA-binding proteins are key regulatory molecules involved primarily in post-transcriptional gene regulation of RNAs. Post-transcriptional gene regulation is critical for adequate cellular growth and survival. Recent reports have shown key interactions between these RNA-binding proteins and other regulatory elements, such as miRNAs and long noncoding RNAs, either enhancing or diminishing their response to RNA stabilization. Many RNA-binding proteins have been reported to play a functional role in mediation of cytokines involved in inflammation and immune dysfunction, and some have been classified as global post-transcriptional regulators of inflammation. The ubiquitous expression of RNA-binding proteins in a wide variety of cell types and their unique mechanisms of degradative action provide evidence that they are involved in reproductive tract pathologies. Aberrant inflammation and immune dysfunction are major contributors to the pathogenesis and disease pathophysiology of many reproductive pathologies, including ovarian and endometrial cancers in the female reproductive tract. Herein, we discuss various RNA-binding proteins and their unique contributions to female reproductive pathologies with a focus on those mediated by aberrant inflammation and immune dysfunction.