Acquisition of useful sero-diagnostic autoantibodies using the same patients'sera and tumor tissues

Calbindin S100A16 Promotes Renal Cell Carcinoma Progression and Angiogenesis via the VEGF/VEGFR2 Signaling Pathway

Purpose

Recent research has indicated that the calcium-binding protein S100A16 promotes carcinogenesis and tumor growth in several forms of cancer. The objective of this study was to examine the relationship between S100A16 and renal cell cancer.

Methods

By using The Cancer Genome Atlas (TCGA) database, the differentially expressed gene S100A16 was identified, and its appearance and link to the prognosis of persons with renal cancer were confirmed. Cox regression was used in multivariate analysis, and a nomogram was developed for internal validation. The correlation between S100A16 and immune cells was analyzed in the TIMER database. Moreover, the potential mechanism of action was investigated utilizing GO and KEGG enrichment analyses. Proliferation, migration, and angiogenesis were investigated in vitro, and the involvement of S100A16 in the undesirable biological events of renal cell carcinoma (RCC) was further explored.

Results

S100A16 was the differentially expressed molecule identified through database screening. Malignant tissues showed higher S100A16 expression than noncancerous tissues, and S100A16 expression was mostly localized in the cytoplasm. According to the TCGA and KM-plotter datasets, patients with RCC and low S100A16 expression had superior OS, PFI, and DSS. The C-index of the nomogram was 0.754 (0.726–0.782), and the accuracy of the prediction model was high. The TIMER database shows that the expression of S100A16 is associated with immune infiltration and may play an important role in promoting tumor cell immune escape in the RCC tumor microenvironment. S100A16 may influence the biological processes of RCC via the VEGF/VEGFR2 signaling route and PI3K-Akt signaling pathway and through P53 alteration and cell cycle according to the gene enrichment technique. In vitro cytological experiments demonstrated that S100A16 knockdown can inhibit the proliferation and migration of renal cancer cells and the expression levels of VEGF, VEGFR2, and phosphorylated AKT within renal cancer cells, thereby inhibiting angiogenesis in renal cancer cells and resulting in a poor prognosis of RCC.

Conclusion

A decrease in S100A16 expression may dramatically increase the OS, PFI, and DSS of patients with RCC and may thus be used as a biomarker for predicting RCC. It may be associated with the immune infiltration of RCC and play a crucial role in the immune evasion of tumor cells within the RCC microenvironment. Intervention of s100a16 can promote the progression and angiogenesis of renal cell carcinoma through the VEGF/VEGFR2 signal transduction pathway and lead to poor prognosis of renal cell carcinoma. These findings suggest a potential target for the development of anticancer strategies for renal cancer.

Prognostic and clinicopathological significance of CapG in various cancers: Evidence from a meta-analysis

BACKGROUND

The gelsolin-like actin-capping protein (CapG) is an actin-binding protein in the gelsolin superfamily. Increasing evidence indicates that CapG is highly expressed in various types of cancer. However, the role of CapG in malignant tumors is still controversial. Therefore, we conducted a meta-analysis to assess the prognostic value and clinicopathological significance of CapG in malignant tumors.

METHOD

We searched for eligible studies in the PubMed, Web of Science, Embase, and Cochrane databases. Stata SE12.0 software was used for quantitative meta-analysis. The hazard ratios (HRs) and odds ratios (ORs) with 95% CI were pooled to assess the relationship between CapG expression and overall survival (OS), as well as clinicopathological parameters.

RESULTS

Sixteen studies with a total of 1987 cancer patients were included in this meta-analysis. The results showed that higher CapG expression was statistically correlated with shorter OS (HR 1.70, 95% CI 1.43-1.97, P < 0.001), positive lymph node metastasis (OR 1.91, 95% CI 1.19-3.09, P =  0.008), advanced TNM stage (OR 1.87, 95% CI 1.17-3.00, P = 0.009), advanced T-primary stage (OR 2.54, 95% CI 1.08-6.00, P =  0.033) and male sex (OR 1.77, 95% CI 1.23-2.56, P =  0.002). However, no significant correlation was observed between increased CapG expression and advanced age, larger tumor size, differentiation, or advanced histopathologic grading (P > 0.05).

CONCLUSIONS

High CapG expression is associated with a poor prognosis and worse clinicopathological parameters in various cancers. CapG is a potential prognostic biomarker and a possible clinicopathological predictive factor for various cancers.

Function of the macrophage-capping protein in colorectal carcinoma

To investigate the role of macrophage-capping protein (CapG) in the development and progression of colorectal carcinoma (CRC), immunohistochemistry (IHC), Kaplan-Meier survival analysis, wound healing and Transwell migration assays were performed. The IHC results demonstrated that CapG was relatively highly expressed in CRC tissue compared with non-tumor tissue (P<0.001), and that the expression of CapG was significantly associated with the tumor site, differentiation, lymph node metastasis and clinical stage (P=0.021, P=0.036, P=0.012 and P=0.009, respectively). Wound healing and Transwell migration assays demonstrated that the reduction of CapG expression in a CRC cell line by RNA interference was associated with significantly impaired motility (P<0.001). Kaplan-Meier survival analysis revealed that the expression of CapG in tumor samples was not significantly associated with disease-free survival time. In conclusion, CapG was overexpressed in CRC and was associated with tumor progression; therefore, it may be a useful prognostic biomarker and therapeutic target in CRC.

Autoantibodies against oncogenic ERG protein in prostate cancer: potential use in diagnosis and prognosis in a panel with C-MYC, AMACR and HERV-K Gag

Overdiagnosis and overtreatment of prostate cancer (CaP) is attributable to widespread reliance on PSA screening in the US. This has prompted us and others to search for improved biomarkers for CaP, to facilitate early detection and disease stratification. In this regard, autoantibodies (AAbs) against tumor antigens could serve as potential candidates for diagnosis and prognosis of CaP. Towards this, our goals were: i) To investigate whether AAbs against ERG oncoprotein (overexpressed in 25-50% of Caucasian American and African American CaP) are present in the sera of CaP patients; ii) To evaluate an AAb panel to enhance CaP detection. The results using an enzyme-linked immunosorbent assay (ELISA) showed that anti-ERG AAbs are present in a significantly higher proportion in the sera of CaP patients compared to healthy controls (p = 0.0001). Furthermore, a panel of AAbs against ERG, AMACR and human endogenous retrovirus-K Gag successfully differentiated CaP patient sera from healthy controls (AUC = 0.791). These results demonstrate for the first time that anti-ERG AAbs are present in the sera of CaP patients. In addition, the data also suggest that AAbs against ERG together with AMACR and HERV-K Gag may be a useful panel of biomarkers for diagnosis and prognosis of CaP.

Calnexin is a novel sero-diagnostic marker for lung cancer

To develop sero-diagnostic markers for lung cancer, we generated monoclonal antibodies using lung adenocarcinoma (AC)-derived A549 cells as antigens by employing the random immunization method. Hybridoma supernatants were immunohistochemically screened for antibodies with AMeX-fixed and paraffin-embedded A549 cell preparations. Positive clones were monocloned twice through limiting dilutions. From the obtained monoclonal antibodies, one designated as KU-Lad-001 was recognized as calnexin (CANX) based on immunoprecipitation and MADLI TOF/TOF-MS analysis. To evaluate the utility of this antibody as a sero-diagnostic marker for lung cancer, we performed reverse-phase protein array analysis with samples of 195 lung cancer patients and 100 healthy controls. The CANX expression levels were significantly higher in lung cancer patients than in healthy controls (P<0.0001), and the area under the curve of ROC was 0.980, with 96.9% specificity and 99.0% sensitivity. Furthermore, since CANX was also detected in stage I disease, the serum CANX levels should be applicable markers discriminating lung cancer patients from healthy controls and possibly used in the detection of early lung cancer. To our knowledge, the present results provide evidence that CANX may be a novel sero-diagnostic marker for lung cancer.