Prognostic Significance of SPARC Expression in Breast Cancer: A Meta-Analysis and Bioinformatics Analysis

EXPRESSION OF SPP1 AND SPARC GENES IN TUMOR TISSUE OF PATIENTS WITH BREAST CANCER

BACKGROUND

Breast cancer (BCa) is one of the most common oncological diseases in women in Ukraine and worldwide, which determines the need to search for new diagnostic and prognostic markers. In this aspect, the study of multicellular proteins, in particular osteopontin (OPN) and osteonectin (ON), in BCа tissue is relevant. The aim of the work was to investigate the expression of SPP1 and SPARC at the mRNA and protein levels in BCa tissue and to assess their relationship with the main clinicopathological BCa characteristics and the survival rates of patients.

MATERIALS AND METHODS

The work was based on the analysis of the results of the examination and treatment of 60 patients with stage II-III BCa and 15 patients with breast fibroadenomas. SPP1 and SPARC mRNA levels were determined by real-time PCR. The study of the expression of protein products of the SPP1 and SPARC genes was carried out by the immunohistochemical method.

RESULTS

We have established that the BCa tissue was characterized by 3.5 (p < 0.05) and 7.4 (p < 0.05) lower levels of SPP1 and SPARC mRNA, respectively, compared to the tissue of benign neoplasms, while OPN and ON expression levels were 1.6 (p < 0.05) and 5.6 (p < 0.05) times higher, respectively, compared to fibroadenoma tissue. The analysis of the relationship between the expression of SPP1 and SPARC at the protein and mRNA levels in BCa tissue and the main clinicopathological BCa characteristics revealed its dependence on the presence of metastases in regional lymph nodes, differentiation grade, and the molecular BCa subtype. Also, high expression levels of SPP1 and OPN were associated with worse patient survival rates.

CONCLUSION

The obtained results indicate the perspective of using SPP1 and SPARC expression indices in BCa tissue to assess the aggressiveness of the cancer course and optimize the tactics of treating patients.

Osteonectin (SPARC) prognostic value in prostate cancer

BACKGROUND

Prostate cancer (PCa) is common malignancy among men worldwide. To date only few molecular markers are available to predict its course and outcome. SPARC is considered to be promising prognostic marker of PCa due to its involvement in various cancer processes.

MATERIALS AND METHODS

study was conducted on PCa surgical primary tumor samples, obtained from 84 patients. Level of SPARC mRNA expression was estimated using RT-qPCR. To identify SPARC protein (osteonectin) in prostate tissue, immunohistochemical analysis was conducted. Bioinformatical analysis was performed on UALCAN and TNMplot resources.

RESULTS

bioinformatical analysis demonstrated that SPARC mRNA levels are decreased in PCa samples, in comparison to normal tissue. In patients with lymph node metastases its levels are 1.26 times higher; p = 4.66E-02, than in N0 category. Ex vivo study demonstrated that SPARC expression was elevated on both mRNA and protein levels in PCa patients with lymph node metastases (by 2.34 and 1.91, respectively, p < 0.05). We established higher levels of SPARC mRNA and protein in PCa patients with T3 tumors, as well as high Gleason score. Estimation of survival rates demonstrated that PCa patients with a high level of SPARC mRNA and protein have decreased overall 2-year survival.

CONCLUSIONS

SPARC protein was overexpressed on mRNA and protein levels in patients with presence of lymph node metastases and higher Gleason score of tumors. Also, both mRNA and protein upregulation were associated with worse survival rates. The current study has therefore provided further evidence that SPARC is indeed linked to the prognosis and aggressiveness of human PCa.

Targeted Therapies and Drug Resistance in Advanced Breast Cancer, Alternative Strategies and the Way beyond

"Targeted therapy" or "precision medicine" is a therapeutic strategy launched over two decades ago. It relies on drugs that inhibit key molecular mechanisms/pathways or genetic/epigenetic alterations that promote different cancer hallmarks. Many clinical trials, sponsored by multinational drug companies, have been carried out. During this time, research has increasingly uncovered the complexity of advanced breast cancer disease. Despite high expectations, patients have seen limited benefits from these clinical trials. Commonly, only a minority of trials are successful, and the few approved drugs are costly. The spread of this expensive therapeutic strategy has constrained the resources available for alternative research. Meanwhile, due to the high cost/benefit ratio, other therapeutic strategies have been proposed by researchers over time, though they are often not pursued due to a focus on precision medicine. Notable among these are drug repurposing and counteracting micrometastatic disease. The former provides an obvious answer to expensive targeted therapies, while the latter represents a new field to which efforts have recently been devoted, offering a "way beyond" the current research.

Secreted Protein Acidic and Rich in Cysteine (SPARC) Polymorphisms in Response to Neoadjuvant Chemotherapy in HER2-Negative Breast Cancer Patients

Secreted protein acidic and rich in cysteine (SPARC) expression has been proposed as a prognostic and predictive biomarker for some cancer types, but knowledge about the predictive value of SPARC polymorphisms in the context of neoadjuvant therapy for breast cancer (BC) is lacking. In 132 HER2-negative BC patients treated with neoadjuvant chemotherapy, we determined polymorphisms in the SPARC gene and analyzed their association with outcome. We also determined SPARC protein expression in tumor tissue. SPARC rs19789707 was significantly associated with response to treatment according to the Miller and Payne system in the breast (multivariate: odds ratio (OR), 3.81; p = 0.028). This association was significant in the subgroup of patients with luminal tumors (univariate: p = 0.047). Regarding survival, two SPARC variants showed significant associations with event-free survival: the rs19789707 variant in the subgroup of luminal A tumors (univariate: p = 0.006), and the rs4958487 variant in the subgroup of luminal B tumors (univariate: p = 0.022). In addition, SPARC rs4958487, rs10065756, and rs12153644 were significantly correlated with SPARC protein expression. Our findings suggest that SPARC polymorphisms could be good predictors of treatment response and survival in BC patients treated with neoadjuvant chemotherapy, especially those with luminal tumors.

Impact of SPARC expression on treatment response of pembrolizumab and brain metastasis in patients with metastatic non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) often exhibits elevated Secreted Protein Acidic and Cysteine-Rich (SPARC) expression. In this study, we investigated the impact of SPARC expression on clinicopathologic features, pembrolizumab response, and prognosis in metastatic NSCLC patients.

METHODS

Thirty-six patients diagnosed with metastatic NSCLC without actionable driver mutation and who received pembrolizumab with or without chemotherapy were included in this study. PD-L1 and SPARC expression were evaluated, with PD-L1 expression categorized based on tumor proportion score and SPARC staining intensity graded as 1+, 2+, and 3 +. Patients' characteristics were compared across groups, and possible predictive markers were determined by binary logistic regression analysis.

RESULTS

No significant associations were found between SPARC expression and smoking status, histopathological tumor type, T and N status, and liver and bone metastasis. Higher SPARC expression was significantly linked to lower brain metastasis rates but higher CNS progression rates (p = 0.022 and p = 0.011, respectively. The objective response rate (ORR) showed a trend of being higher in the SPARC 1 + group (85.7% vs. 43.8% and 50.0% in 2 + and 3 + groups, respectively, p = 0.052. Univariate analysis did not find SPARC expression to be a significant prognostic factor for progression-free survival (PFS) (p = 0.7) and overall survival (OS) (p = 0.07).SPARC 1 + expression negatively affected the pembrolizumab response(p = 0.04,OR:0.11, 95%CI 0.01-0.92).

CONCLUSIONS

Our study sheds light on a novel aspect of SPARC expression as a potential predictor of pembrolizumab response and a marker for CNS progression in metastatic NSCLC patients treated in the first-line setting.

Glucose oxidase virus-based nanoreactors for smart breast cancer therapy

BACKGROUND

Breast cancer is the most common malignant tumor disease and the leading cause of female mortality. The evolution of nanomaterials science opens the opportunity to improve traditional cancer therapies, enhancing therapy efficiency and reducing side effects.

METHODS AND MAJOR RESULTS

Herein, protein cages conceived as enzymatic nanoreactors were designed and produced by using virus-like nanoparticles (VLPs) from Brome mosaic virus (BMV) and containing the catalytic activity of glucose oxidase (GOx) enzyme. The GOx enzyme was encapsulated into the BMV capsid (VLP-GOx), and the resulting enzymatic nanoreactors were coated with human serum albumin (VLP-GOx@HSA) for breast tumor cell targeting. The effect of the synthesized GOx nanoreactors on breast tumor cell lines was studied in vitro. Both nanoreactor preparations VLP-GOx and VLP-GOx@HSA showed to be highly cytotoxic for breast tumor cell cultures. Cytotoxicity for human embryonic kidney cells was also found. The monitoring of nanoreactor treatment on triple-negative breast cancer cells showed an evident production of oxygen by the catalase antioxidant enzyme induced by the high production of hydrogen peroxide from GOx activity.

CONCLUSIONS AND IMPLICATIONS

The nanoreactors containing GOx activity are entirely suitable for cytotoxicity generation in tumor cells. The HSA functionalization of the VLP-GOx nanoreactors, a strategy designed for selective cancer targeting, showed no improvement in the cytotoxic effect. The GOx containing enzymatic nanoreactors seems to be an interesting alternative to improve the current cancer therapy. In vivo studies are ongoing to reinforce the effectiveness of this treatment strategy.

SPARC: a potential target for functional nanomaterials and drugs

Secreted protein acidic and rich in cysteine (SPARC), also termed osteonectin or BM-40, is a matricellular protein which regulates cell adhesion, extracellular matrix production, growth factor activity, and cell cycle. Although SPARC does not perform a structural function, it, however, modulates interactions between cells and the surrounding extracellular matrix due to its anti-proliferative and anti-adhesion properties. The overexpression of SPARC at sites, including injury, regeneration, obesity, cancer, and inflammation, reveals its application as a prospective target and therapeutic indicator in the treatment and assessment of disease. This article comprehensively summarizes the mechanism of SPARC overexpression in inflammation and tumors as well as the latest research progress of functional nanomaterials in the therapy of rheumatoid arthritis and tumors by manipulating SPARC as a new target. This article provides ideas for using functional nanomaterials to treat inflammatory diseases through the SPARC target. The purpose of this article is to provide a reference for ongoing disease research based on SPARC-targeted therapy.

Omics Overview of the SPARC Gene in Mesothelioma

The SPARC gene plays multiple roles in extracellular matrix synthesis and cell shaping, associated with tumor cell migration, invasion, and metastasis. The SPARC gene is also involved in the epithelial-mesenchymal transition (EMT) process, which is a critical phenomenon leading to a more aggressive cancer cell phenotype. SPARC gene overexpression has shown to be associated with poor survival in the mesothelioma (MESO) cohort from the TCGA database, indicating that this gene may be a powerful prognostic factor in MESO. Its overexpression is correlated with the immunosuppressive tumor microenvironment. Here, we summarize the omics advances of the SPARC gene, including the summary of SPARC gene expression associated with prognosis in pancancer and MESO, the immunosuppressive microenvironment, and cancer cell stemness. In addition, SPARC might be targeted by microRNAs. Notably, despite the controversial functions on angiogenesis, SPARC may directly or indirectly contribute to tumor angiogenesis in MESO. In conclusion, SPARC is involved in tumor invasion, metastasis, immunosuppression, cancer cell stemness, and tumor angiogenesis, eventually impacting patient survival. Strategies targeting this gene may provide novel therapeutic approaches to the treatment of MESO.

Clinicopathological and prognostic significance of SPARC expression in gastric cancer: A meta‑analysis and bioinformatics analysis

Secreted protein acidic and rich in cysteine (SPARC) is a member of the extracellular matrix glycoprotein family that binds to calcium ions. It may bind to a variety of proteins in the extracellular matrix and also compete with cell membrane surface receptors for growth. In the present study, the relationship between SPARC expression in gastric cancer tissues and the clinicopathological characteristics and prognosis of patients with gastric cancer were systematically evaluated. A meta-analysis and bioinformatics analysis were performed using the PubMed, Chinese National Knowledge Infrastructure, Kaplan-Meier (KM)-plotter, The Cancer Genome Atlas (TCGA), Gene Expression Profiling Interactive Analysis (GEPIA), University of ALabama at Birmingham CANcer (UALCAN), Human Protein Atlas (HPA) and Timer databases. SPARC was mainly expressed in tumor mesenchymal cells. The meta-analysis indicated that SPARC expression was higher in gastric cancer tissues than in normal tissues. SPARC was associated with the degree of differentiation and distant metastasis. K-M plotter results indicated that high SPARC expression was negatively associated with overall survival, post-progression survival and progression-free survival rates of patients. According to the Oncomine, GEPIA, UALCAN and HPA databases, SPARC mRNA and protein expression was upregulated in gastric cancer vs. normal tissues and was negatively associated with poor patient prognosis. In the TCGA database, univariate analysis indicated that lymph node metastasis and distant metastasis were associated with the prognosis of patients with gastric cancer. Cox multifactorial analysis suggested that high SPARC expression, age and distant metastasis were important factors affecting the survival time of patients with gastric cancer. Analysis with the Timer database indicated that SPARC was closely associated with the proportion of 7 immune-cell infiltrates in gastric cancer. These findings indicated that high expression of SPARC may be a potential marker of tumorigenesis and metastasis in patients with gastric cancer.

Tetrahydrocurcumin Chemosensitizes Breast Cancer to Albumin-Bound Paclitaxel by Enhancing SPARC Expression through Demethylation

Paclitaxel is an effective chemotherapy drug for breast cancer (BC); however, drug resistance affects long-term clinical applications. In this study, we aimed to explore whether a natural compound, tetrahydrocurcumin (THC), could sensitize BC to albumin-bound paclitaxel (ab-PTX). The in vitro sensitization effect of THC to ab-PTX was evaluated in human BC cell lines, and in vivo chemosensitivity was measured using a xenograft BC tumor model. The expression of secreted protein acidic and rich in cysteine (SPARC), a speculated protein interacting with ab-PTX, was measured. Methylation-specific polymerase chain reaction (MSP) was used to further explore whether demethylation of SPARC by THC contributed to its chemosensitivity capabilities. Higher SPARC expression was correlated with a better prognosis in patients with BC. In vitro analysis showed THC enhanced the inhibitory effect of ab-PTX on BC cells and xenograft tumors and showed significant chemosensitivity. This enhancement mainly relied on upregulating the expression of SPARC through downregulating methylation of the SPARC gene. The demethylating agent, 5-Aza-2′-deoxycytidine (5-Aza-Cdr), decreased THC's chemosensitivity effect, further confirming this molecular mechanism. THC enhanced the inhibitory effect of ab-PTX in BC by downregulating methylation of the SPARC gene. Further, upregulated SPARC increased the efficacy of ab-PTX.