The interrelationships between Src, Cav-1 and RhoGD12 in transitional cell carcinoma of the bladder

Pan-cancer Analysis Reveals SRC May Link Lipid Metabolism and Macrophages

Background

SRC is a member of the membrane-associated non-receptor protein tyrosine kinase superfamily. It has been reported to mediate inflammation and cancer. However, the exact molecular mechanism involved is still not clear.

Objectives

The current study was designed to explore the prognostic landscape of SRC and further investigate the relationship between SRC and immune infiltration in pan-cancer.

Materials and Methods

Kaplan-Meier Plotter was used to detect the prognostic value of SRC in pan-cancer. Then using TIMER2.0 and CIBERSORT, the relationship between SRC and immune infiltration in pan-cancer was evaluated. Furthermore, the LinkedOmics database was used to screen SRC co-expressed genes, followed by functional enrichment of SRC co-expressed genes by Metascape online tool. STRING database and Cytoscape software were applied to construct and visualise the protein-protein interaction network of SRC co-expressed genes. MCODE plug-in was used to screen hub modules in the PPI network. The SRC co-expressed genes in hub modules were extracted, and the correlation analysis between interested SRC co-expressed genes and immune infiltration was conducted via TIMER2.0 and CIBERSORT.

Results

Our study demonstrated that SRC expression was significantly associated with overall survival and relapse-free survival in multiple cancer types. In addition, SRC expression was significantly correlated with the immune infiltration of B cells, dendritic cells, CD4⁺ T cells, macrophages, and neutrophils in pan-cancer. The expression of SRC had shown to have close correlations with M1 macrophage polarisation in LIHC, TGCT, THCA, and THYM. Moreover, the genes that co-expressed with SRC in LIHC, TGCT, THCA, and THYM were mainly enriched in lipid metabolism. Besides, correlation analysis showed that SRC co-expressed genes associated with lipid metabolism were also significantly correlated with the infiltration and polarisation of macrophages.

Conclusion

These results indicate that SRC can serve as a prognostic biomarker in pan-cancer and is related to macrophages infiltration and interacts with genes involved in lipid metabolism.

The clinicopathological characteristics of muscle-invasive bladder recurrence in upper tract urothelial carcinoma

This study aimed to clarify the clinical characteristics and oncological outcomes of patients with upper tract urothelial carcinoma (UTUC) who developed muscle-invasive bladder cancer (MIBC) after radical nephroureterectomy (RNU). We identified 966 pTa-4N0-2M0 patients with UTUC who underwent RNU and clarified the risk factors for MIBC progression after initial intravesical recurrence (IVR). We also identified 318 patients with primary pT2-4N0-2M0 MIBC to compare the oncological outcomes with those of patients with UTUC who developed or progressed to MIBC. Furthermore, immunohistochemical examination of p53 and FGFR3 expression in tumor specimens was performed to compare UTUC of MIBC origin with primary MIBC. In total, 392 (40.6%) patients developed IVR after RNU and 46 (4.8%) developed MIBC at initial IVR or thereafter. As a result, pT1 stage on the initial IVR specimen, concomitant carcinoma in situ on the initial IVR specimen, and no intravesical adjuvant therapy after IVR were independent factors for MIBC progression. After propensity score matching adjustment, primary UTUC was a favorable indicator for cancer-specific death compared with primary MIBC. Subgroup molecular analysis revealed high FGFR3 expression in non-MIBC and MIBC specimens from primary UTUC, whereas low FGFR3 but high p53 expression was observed in specimens from primary MIBC tissue. In conclusion, our study demonstrated that patients with UTUC who develop MIBC recurrence after RNU exhibited the clinical characteristics of subsequent IVR more than those of primary UTUC. Of note, MIBC subsequent to UTUC may have favorable outcomes, probably due to the different molecular biological background compared with primary MIBC.

Role of the MUC1-C oncoprotein in the acquisition of cisplatin resistance by urothelial carcinoma

Mucin 1 C-terminal subunit (MUC1-C) has been introduced as a key regulator for acquiring drug resistance in various cancers, but the functional role of MUC1-C in urothelial carcinoma (UC) cells remains unknown. We aimed to elucidate the molecular mechanisms underlying the acquisition of cisplatin (CDDP) resistance through MUC1-C oncoprotein in UC cells. MUC1-C expression was examined immunohistochemically in tumor specimens of 159 UC patients who received CDDP-based perioperative chemotherapy. As a result, moderate to high MUC1-C expression was independently associated with poor survival in UC patients. Using human bladder cancer cell lines and CDDP-resistant (CR) cell lines, we compared the expression levels of MUC1-C, multiple drug resistance 1 (MDR1), the PI3K-AKT-mTOR pathway, and x-cystine/glutamate transporter (xCT) to elucidate the biological mechanisms contributing to the acquisition of chemoresistance. MUC1-C was strongly expressed in CR cell lines, followed with MDR1 expression via activation of the PI3K-AKT-mTOR pathway. MUC1-C also stabilized the expression of xCT, which enhanced antioxidant defenses by increasing intracellular glutathione (GSH) levels. MUC1 down-regulation showed MDR1 inhibition along with PI3K-AKT-mTOR pathway suppression. Moreover, it inhibited xCT stabilization and resulted in significant decreases in intracellular GSH levels and increased reactive oxygen species (ROS) generation. The MUC1-C inhibitor restored sensitivity to CDDP in CR cells and UC murine xenograft models. In conclusion, we found that MUC1-C plays a pivotal role in the acquisition of CDDP resistance in UC cells, and therefore the combined treatment of CDDP with a MUC1-C inhibitor may become a novel therapeutic option in CR UC patients.

BSA-bounded p-cresyl sulfate potentiates the malignancy of bladder carcinoma by triggering cell migration and EMT through the ROS/Src/FAK signaling pathway

Para-cresyl sulfate (P-CS), a major uremic toxin derived from the metabolites of tyrosine and phenylalanine through liver, existed in the blood of patients with chronic kidney disease (CKD). CKD increases the malignancy in bladder cancers; however, effects of P-CS on bladder cancers are not fully understood. P-CS is conjugated with BSA physiologically, and this study aims to investigate the effects and possible underlying mechanisms of BSA-bounded P-CS on human bladder cancer cells. With P-CS treatment, the intracellular ROS increased in bladder cancer cells. ROS then triggered epithelial-mesenchymal transition (EMT), stress fiber redistribution, and cell migration. With specific inhibitors, the key signals regulating P-CS-treated migration are Src and FAK. This study provided a clinical clue that patients with higher serum P-CS have a higher risk of malignant urothelial carcinomas, and a regulatory pathway of how P-CS regulates bladder cancer migration.

A Tyrosine Kinase Expression Signature Predicts the Post-Operative Clinical Outcome in Triple Negative Breast Cancers

Triple negative breast cancer (TNBC) represent 15% of breast cancers. Histoclinical features and marketed prognostic gene expression signatures (GES) failed to identify good- and poor-prognosis patients. Tyrosine kinases (TK) represent potential prognostic and/or therapeutic targets for TNBC. We sought to define a prognostic TK GES in a large series of TNBC. mRNA expression and histoclinical data of 6379 early BCs were collected from 16 datasets. We searched for a TK-based GES associated with disease-free survival (DFS) and tested its robustness in an independent validation set. A total of 1226 samples were TNBC. In the learning set of samples (N = 825), we identified a 13-TK GES associated with DFS. This GES was associated with cell proliferation and immune response. In multivariate analysis, it outperformed the previously published GESs and classical prognostic factors in the validation set (N = 401), in which the patients classified as "low-risk" had a 73% 5-year DFS versus 53% for "high-risk" patients (p = 1.85 × 10-3). The generation of 100,000 random 13-gene signatures by a resampling scheme showed the non-random nature of our classifier, which was also prognostic for overall survival in multivariate analysis. We identified a robust and non-random 13-TK GES that separated TNBC into subgroups of different prognosis. Clinical and functional validations are warranted.

Caveolin-1 promotes pituitary adenoma cells migration and invasion by regulating the interaction between EGR1 and KLF5

Caveolin-1 (Cav-1) is a principal structural protein of caveolae. Cav-1 has been implicated in cancer progression, but its precise functional roles in pituitary adenoma cells remain largely unclear. In this study, we evidenced that the level of cav-1 was elevated in the invasive pituitary adenoma. Cav-1 knockdown restrained the migration and invasion of pituitary adenoma cells. In cav-1-depleting cells, the expression of miR-145, miR-124 and miR-183 were up-regulated. Further investigation showed that cav-1 knockdown inhibited the nuclear translocation of EGR1, reducing the interaction between EGR1 and KLF5. The resulting free KLF5 promoted the expression of miR-145, miR-124 and miR-183 by binding to their promoters, which was blocked by EGR1. Luciferase reporter assay indicated that miR-145 targeted FSCN1, miR-124 targeted PTTG1IP, and miR-183 targeted EZR in pituitary adenoma cells, respectively. Knockdown of FSCN1, PTTG1IP or EZR suppressed the migration and invasion of pituitary adenoma cells. In conclusion, our data suggested that the elevated cav-1 promoted pituitary adenoma cells migration and invasion by regulating the interaction between EGR1 and KLF5.

Role of downregulated miR-133a-3p expression in bladder cancer: a bioinformatics study

It has been discovered that miR-133a-3p acts as a tumor suppressor in bladder cancer (BC). Nevertheless, the function of miR-133a-3p in BC remains unclarified. Thus, we carried out this study to validate the expression of miR-133a-3p in BC and provide insights into the molecular mechanism underlying it. To assess the expression of miR-133a-3p in BC, we searched eligible studies from literature and Gene expression Omnibus (GEO) to perform a meta-analysis. We also plotted the summary receiver operating characteristic (SROC) curve to evaluate the diagnostic ability of miR-133a-3p in BC. Additionally, the potential target genes of miR-133a-3p were acquired from 14 online software programs and GEO database. Protein-protein interaction (PPI) network was created to identify the hub genes. Then, Gene Ontology (GO) functional annotation analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were carried out to investigate the regulatory network of the target genes. From the meta-analysis, miR-133a-3p was remarkably downregulated in BC tissues compared with that in non-cancer tissues (standard mean difference =−3.84, 95% confidence interval =−6.99–0.29). Moreover, results from SROC suggested that miR-133a-3p exhibited the ability to diagnose BC (area under curve =0.8418). As for the bioinformatics study, 488 genes were chosen as the potential targets of miR-133a-3p in BC, among which 10 genes were defined as hub genes (all degrees >5). Further GO and KEGG pathway analysis indicated that the target genes of miR-133a-3p aggregated in specific biological process and pathways. In conclusion, miR-133a-3p possessed great diagnostic potential with its downregulation in BC, and miR-133a-3p might serve as a novel biomarker for BC.

Enhanced expression of caveolin-1 possesses diagnostic and prognostic value and promotes cell migration, invasion and sunitinib resistance in the clear cell renal cell carcinoma

Caveolin-1 (CAV1) has been identified to be up-regulated in many cancers, including clear cell renal cell carcinoma (ccRCC). However, its potential function is still unclear in ccRCC. In this study, we demonstrated that CAV1 was frequently overexpressed in renal cell carcinoma tissues and cells, and was significantly associated with various clinicopathological parameters. In addition, high CAV1 expression was associated with poor disease-free survival (DFS) rate and could serve as a useful diagnostic indicator in ccRCC patients with different clinicopathological stages. Functional experiments demonstrated that CAV1 knockdown inhibited cell migration and invasion, whereas overexpression of CAV1 promoted cell migration and invasion in ccRCC. Moreover, CAV1 expression was up-regulated in sunitinib-resistant renal cancer cell lines, and its overexpression promoted sunitinib resistance. In general, our results confirm that CAV1 plays an important role in the metastasis of kidney cancer and induces sunitinib resistance, so CAV1 function suppression may become a promising clinical treatment strategy during renal cell carcinoma metastasis and sunitinib resistance.

Temporally sequenced anticancer drugs overcome adaptive resistance by targeting a vulnerable chemotherapy-induced phenotypic transition

Understanding the emerging models of adaptive resistance is key to overcoming cancer chemotherapy failure. Using human breast cancer explants, in vitro cell lines, mouse in vivo studies and mathematical modelling, here we show that exposure to a taxane induces phenotypic cell state transition towards a favoured transient CD44^HiCD24^Hi chemotherapy-tolerant state. This state is associated with a clustering of CD44 and CD24 in membrane lipid rafts, leading to the activation of Src Family Kinase (SFK)/hemopoietic cell kinase (Hck) and suppression of apoptosis. The use of pharmacological inhibitors of SFK/Hck in combination with taxanes in a temporally constrained manner, where the kinase inhibitor is administered post taxane treatment, but not when co-administered, markedly sensitizes the chemotolerant cells to the chemotherapy. This approach of harnessing chemotherapy-induced phenotypic cell state transition for improving antitumour outcome could emerge as a translational strategy for the management of cancer.

Adaptive resistance is an emerging cause of chemotherapy failure in cancer. Here the authors show that adaptive resistance to taxanes is mediated by the upregulation of SFK/Hck survival signalling, and that sequential administration of taxanes and SFK/Hck inhibition restores tumor cell chemosensitivity.

Molecular biology of bladder cancer: new insights into pathogenesis and clinical diversity

Urothelial carcinoma of the bladder comprises two long-recognized disease entities with distinct molecular features and clinical outcome. Low-grade non-muscle-invasive tumours recur frequently but rarely progress to muscle invasion, whereas muscle-invasive tumours are usually diagnosed de novo and frequently metastasize. Recent genome-wide expression and sequencing studies identify genes and pathways that are key drivers of urothelial cancer and reveal a more complex picture with multiple molecular subclasses that traverse conventional grade and stage groupings. This improved understanding of molecular features, disease pathogenesis and heterogeneity provides new opportunities for prognostic application, disease monitoring and personalized therapy.

Value of caveolin-1 in cancer progression and prognosis: Emphasis on cancer-associated fibroblasts, human cancer cells and mechanism of caveolin-1 expression (Review)

Caveolin-1 (Cav-1) is found predominately in terminally differentiated cells, such as adipocytes, endothelia and smooth muscle cells, as well as type I pneumocytes. As a main structural component of caveolae, Cav-1 is important in modulating cellular signaling. In the present study, the expression and clinical role of Cav-1 were analyzed in tumor stromal and human cancer cells, respectively. The results of previous studies have shown that the downregulation of tumor stromal Cav-1 promotes tumor survival and predicts a poor tumor prognosis, predominantly concentrating on the mechanism of the metabolism of the cancer microenvironment (according to the autophagic tumor stroma model of cancer metabolism and the reverse Warburg effect). However, contradictory results concerning the expression, clinical roles and associated mechanisms of Cav-1 have been reported. An improved understanding of Cav-1 expression in tumor stromal and cancer cells will increase knowledge with regard to the clinical value of Cav-1 and its detailed mechanisms. This review summarizes the novel data concerning the clinical values and probable mechanisms of Cav-1 expression in tumor stromal (predominantly in cancer-associated fibroblasts) and cancer cells, respectively.

Src activity is increased in gastrointestinal stromal tumors--analysis of associations with clinical and other molecular tumor characteristics

BACKGROUND

Increased activity of Src has been found in several human cancers, and often is associated with poor clinical outcome. The present study aimed to determine whether Src activity is increased in gastrointestinal stromal tumors (GIST), and whether it correlates with established tumor or patient characteristics and prognosis.

METHODS

Tumor/normal tissues of 29 patients were analyzed for Src activity/protein with kinase assays, and for VEGF/VEGFR with immunohistochemical staining.

RESULTS

Src activity was higher in tumor than in normal tissues (P = 0.093). However, when imatinib responders were excluded from the analyses, it was significantly higher in the tumor tissue (P = 0.017). Additionally, it was higher in primary compared to recurrent tumors or metastasis (P = 0.04). Univariate survival analysis showed a longer overall survival for patients with high Src activity (P = 0.038). In multivariate analysis, the response to imatinib treatment was the only survival-influencing factor (P = 0.072).

CONCLUSIONS

Src activity is increased in GIST. In contrast to most other tumor entities, it does not correlate with poor clinical outcome, but decreases during the progression from primary tumor to recurrence and metastasis, especially under therapy with imatinib. Additionally, our results show that higher Src activity is associated with longer overall survival.

Epithelial membrane protein 2 is a prognostic indictor for patients with urothelial carcinoma of the upper urinary tract

Upper urinary tract urothelial carcinoma is a relatively uncommon disease and is diagnosed more frequently at advanced stages. The prognosis of these patients mainly has been related to tumor stage and grade. As a result, the definition of prognostic indicators enabling precise patient selection is mandatory for neoadjuvant or adjuvant therapies. The epithelial membrane protein (EMP2) was identified as one of the up-regulated genes by isoflavones. EMP2 overexpression suppressed foci formation, anchorage-independent growth in vitro, and tumorigenicity in severe combined immunodeficiency mice (all P < 0.05). In addition, a cross-talk between EMP2 and integrins αV and β3 was shown in the regulation of cell adhesion and migration. Higher EMP2 expression was associated with a better progression-free survival (P = 0.008) and cancer-related death (P < 0.001). EMP2 was identified as a tumor-suppressor gene in urinary tract urothelial carcinoma and may be an innovative co-targeting candidate for designing integrin-based cancer therapy.

Bladder cancer: a simple model becomes complex

Bladder cancer is one of the most frequent malignancies in developed countries and it is also characterized by a high number of recurrences. Despite this, several authors in the past reported that only two altered molecular pathways may genetically explain all cases of bladder cancer: one involving the FGFR3 gene, and the other involving the TP53 gene. Mutations in any of these two genes are usually predictive of the malignancy final outcome. This cancer may also be further classified as low-grade tumors, which is always papillary and in most cases superficial, and high-grade tumors, not necessarily papillary and often invasive. This simple way of considering this pathology has strongly changed in the last few years, with the development of genome-wide studies on expression profiling and the discovery of small non-coding RNA affecting gene expression. An easy search in the OMIM (On-line Mendelian Inheritance in Man) database using "bladder cancer" as a query reveals that genes in some way connected to this pathology are approximately 150, and some authors report that altered gene expression (up- or down-regulation) in this disease may involve up to 500 coding sequences for low-grade tumors and up to 2300 for high-grade tumors. In many clinical cases, mutations inside the coding sequences of the above mentioned two genes were not found, but their expression changed; this indicates that also epigenetic modifications may play an important role in its development. Indeed, several reports were published about genome-wide methylation in these neoplastic tissues, and an increasing number of small non-coding RNA are either up- or down-regulated in bladder cancer, indicating that impaired gene expression may also pass through these metabolic pathways. Taken together, these data reveal that bladder cancer is far to be considered a simple model of malignancy. In the present review, we summarize recent progress in the genome-wide analysis of bladder cancer, and analyse non-genetic, genetic and epigenetic factors causing extensive gene mis-regulation in malignant cells.

Expression and prognostic significance of Src family members in renal clear cell carcinoma

BACKGROUND

The aim of this study was to determine whether Src family kinases (SFK) are expressed in renal cell cancer and to assess their prognostic significance.

METHODS

mRNA expression levels were investigated for the 8 SFK members by quantitative real-time PCR in 19 clear cell cancer tissue samples. Immunohistochemical staining was utilised to assess expression of Src kinase, dephosphorylated Src kinase at Y(530) (SrcY(530)), phosphorylated Src at Y(419) (SrcY(419)) and the downstream focal adhesion kinase (FAK) marker at the Y(861) site (FAK Y(861)) in a cohort of 57 clear cell renal cancer specimens. Expression was assessed using the weighted histoscore method.

RESULTS

Src, Lyn, Hck, Fgr and Fyn were the most highly expressed in renal cancer. All members were more highly expressed in T2 disease, and furthermore expression levels between T2 and T3 disease showed a significant decrease for Lck, Lyn, Fyn, Blk and Yes (P=0.032). Assessment of membrane, cytoplasm and nuclear expression of Src kinase, SrcY(530) and SrcY(419) were not significantly associated with cancer-specific survival. High expression of cytoplasmic FAK Y(861) was associated with decreased cancer-specific survival (P=0.001). On multivariate analysis, cytoplasmic FAK Y(861) was independently associated with cancer-specific survival (hazard ratio 3.35, 95% CI 1.40-7.98, P=0.006).

CONCLUSION

We have reported that all SFK members are expressed in renal cell carcinoma. The SFK members had their highest levels of expression before the disease no longer being organ confined. We hypothesise that these SFK members are upregulated before the cancer spreading out-with the organ and given that Src itself is not associated with cancer-specific survival but the presence of FAK Y(861), a downstream marker for SFK member activity is associated with decreased cancer-specific survival, we hypothesise that another SFK member is associated with decreased cancer-specific survival in renal cell cancer.