Prognostic values of osteopontin-c, E-cadherin and β-catenin in breast cancer

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.

Expression pattern of osteopontin isoforms in malignant melanoma cell lines

Osteopontin (OPN) is a secreted integrin-binding protein that plays a role in inflammation, cellular viability, cell adhesion and migration, cancer development, and diabetes through different mechanisms. The splice variants of OPN can play essential roles in cancer development, progression, and metastasis formation; however, limited data are available about the role of OPN isoforms in human malignant melanoma. Our goal was to define the gene expression patterns of five OPN variants (OPN4, OPN5, OPNa, OPNb, and OPNc), integrin, and CD44 receptor genes in primary and metastatic melanoma-originated cell lines (n = 19), and to explore the association of the expression patterns with clinicopathological parameters. We evaluated the invasive property of the cell lines and investigated the potential association between the invasion and gene expression of OPN isoforms. We found a significant rise in the expression of OPNc in the invasive cell lines compared to the noninvasive cells and detected significantly higher expression of the OPN splice variants in melanoma cell lines originating from more advanced stages tumors than cell lines originating from early-stage melanomas. The correlation analysis revealed that all five OPN variants positively correlated with ITGB3 and ITGA9, whereas OPN5 positively correlated with ITGB1, ITGAV, ITGA6, and CD44. OPN can activate extracellular signal-regulated kinase signaling through binding to α9β1 integrin, promoting melanoma tumor cell migration. It is possible that such associations between OPN splice variants and integrin receptors may play a role in melanoma progression. In conclusion, our findings suggest that high expression of OPNc correlates with the invasive behavior of melanoma cells.

Is Osteopontin a Good Marker for Bone Metastasis in Canine Mammary Gland Tumor and Prostate Cancer?

Osteopontin (OPN) is a protein synthesized by a large number of cells, and its overexpression has been associated with the development and prognosis of cancer. OPN overexpression has been claimed to be a marker for the development of bone metastasis in human cancers, but no prior research has investigated the association between OPN expression and the metastasis of canine mammary gland tumors (MGTs) and prostate cancer (PC). Therefore, we investigated OPN expression in MGTs and PC samples from 50 canine patients with or without metastasis (bone vs. other sites). Higher OPN expression was detected in primary tumor samples from animals with bone metastasis than in those without bone involvement (p = 0.0321). In MGT samples, a significantly lower survival rate was observed in patients with higher OPN expression (p = 0.0171). In animals with PC, there was a strong trend toward lower survival in animals with positive OPN expression; however, this trend was not statistically significant (p = 0.0779). From these findings, it can be concluded that OPN may be a promising target for future MGTs and PC studies because of its role in enhancing cell invasion and metastasis.

Meta-analysis of Osteopontin splice variants in cancer

BACKGROUND

The cytokine Osteopontin is a mediator of tumor progression and cancer metastasis. In 2006, we reported that (in addition to the full-length form -a) splice variants of Osteopontin (forms -b and -c) are produced selectively by transformed cells. Through June 2021, 36 PubMed-indexed journal articles have studied Osteopontin splice variants in various cancer patients.

METHODS

Applying a categorical approach previously developed by us, here we conduct a meta-analysis of the pertinent literature. We supplement this with evaluation of the relevant entries in the TSVdb database, which focusses on splice variant expression, thus including the additional variants -4 and -5. The analysis covers 5886 patients across 15 tumors from the literature and 10,446 patients across 33 tumors from TSVdb.

RESULTS

The database yields positive results more frequently than the categorical meta-analysis. The two sources are in agreement on the elevation of OPN-a, OPN-b, and OPN-c in lung cancer and the elevation of OPN-c in breast cancer as compared to healthy tissue. Specific splice variants are associated with grade, stage, or patient survival pertaining to various cancers.

CONCLUSIONS

There are cases of persisting discrepancies, which require further investigation to clarify the Osteopontin splice variant utilization, so that their diagnostic, prognostic and potentially predictive potential can be brought to fruition.

Breast cancer risk in papilloma patients: Osteopontin splice variants indicate prognosis

BACKGROUND

Papillomas of the breast pose challenges for treatment decisions as their risk for transformation to breast cancer is low but not negligible. To spare low-risk patients the burden of substantial treatment side effects, prognostic indicators are needed for cancerous progression. The secreted metastasis mediator Osteopontin (OPN) is a marker for breast cancer aggressiveness, and its variants are prognosticators for transformation in diverse premalignant breast lesions. Here, we test whether the presence of OPN-c or OPN-exon-4 in papillomatous lesions may reflect progression risk.

METHODS

By immunohistochemistry, we analyze OPN-c and OPN-exon-4 in papillomas from 114 women as well as correlations between staining and progression. In departure from prior spliced OPN biomarker publications, we utilize novel monoclonal antibodies.

RESULTS

Fewer than 5% of OPN-c pathology score 0-1 (intensity) versus almost 18% of score 2-3 experienced cancer in follow-up. Nine of 12 women, who progressed, had pathology scores of 2-3 for OPN-c intensity at the time of initial diagnosis, and none had a score of 0. When developing a combined risk score from intensity plus percent positivity for OPN-c, the progression risk for patients with low score was 3.2%, for intermediate score was 5.7%, and for high score was 18.8%. Papillomas in patients, who were later diagnosed with cancer in the contralateral breast, displayed stronger staining positivity than non-progressors.

CONCLUSION

OPN splice variant immunohistochemistry on biopsies of breast papillomas will allow counseling of the patients on their risk to develop breast cancer at a later time.

Gene Expression Patterns of Osteopontin Isoforms and Integrins in Malignant Melanoma

Osteopontin (OPN) is a multifunctional glycoprotein that physiologically interacts with different types of integrins. It is considered to be a possible prognostic biomarker in certain tumor types; however, various splicing isoforms exist, which have not been investigated in melanoma. We aimed to define the relative expression pattern of five OPN isoforms and clarify the prognostic significance of the splice variants in melanoma. We also aimed to investigate the expression pattern of eight integrins in the same tumors. Gene expression analyses revealed that the relative expression of OPNa, OPNb, and OPNc is significantly higher in metastatic tumors compared to primary lesions (p < 0.01), whereas the expression of OPN4 and OPN5 was low in both. The more aggressive nodular melanomas had higher expression levels compared to the superficial spreading subtype (p ≤ 0.05). The relative expression of the eight tested integrins was low, with only the expression of ITGB3 being detectable in nodular melanoma (Median_log2 = 1.274). A positive correlation was found between Breslow thickness and the expression of OPNc variant, whereby thicker tumors (>4 mm) had significantly higher expression (p ≤ 0.05). The Breslow thickness was negatively correlated with the expression of OPN4, and similarly with ITGA2. OPNc also exhibited significant positive correlation with the presence of metastasis. Our data show that high expression of OPNa, OPNb, and especially OPNc and low expression of OPN4 and ITGA2 are associated with an advanced stage of tumor progression and poor prognosis in melanoma.

Reversing an Oncogenic Epithelial-to-Mesenchymal Transition Program in Breast Cancer Reveals Actionable Immune Suppressive Pathways

Approval of checkpoint inhibitors for treatment of metastatic triple negative breast cancer (mTNBC) has opened the door for the use of immunotherapies against this disease. However, not all patients with mTNBC respond to current immunotherapy approaches such as checkpoint inhibitors. Recent evidence demonstrates that TNBC metastases are more immune suppressed than primary tumors, suggesting that combination or additional immunotherapy strategies may be required to activate an anti-tumor immune attack at metastatic sites. To identify other immune suppressive mechanisms utilized by mTNBC, our group and others manipulated oncogenic epithelial-to-mesenchymal transition (EMT) programs in TNBC models to reveal differences between this breast cancer subtype and its more epithelial counterpart. This review will discuss how EMT modulation revealed several mechanisms, including tumor cell metabolism, cytokine milieu and secretion of additional immune modulators, by which mTNBC cells may suppress both the innate and adaptive anti-tumor immune responses. Many of these pathways/proteins are under preclinical or clinical investigation as therapeutic targets in mTNBC and other advanced cancers to enhance their response to chemotherapy and/or checkpoint inhibitors.

Osteopontin isoform c promotes the survival of cisplatin-treated NSCLC cells involving NFATc2-mediated suppression on calcium-induced ROS levels

Background

Tumor microenvironment (TME) critically contributed to the malignant progression of transformed cells and the chemical responses to chemotherapy reagents. Osteopontin (OPN) is a secretory onco-protein with several splicing isoforms, all of which were known to regulate tumor growth and able to alter cell-cell or cell-TME communication, however, the exact role and regulation of the OPN splicing isoforms was not well understood.

Methods

In this study, the effects of conditioned medium from the culture of OPN splicing isoforms overexpressing cells on cell functions were evaluated. The methods of nuclear calcium reporter assays and subcellular distribution of nuclear factor of activated T cells c2 (NFATc2) assays were used to investigate the molecular mechanism underlining the roles of OPN splicing isoforms.

Results

We found that the survival of NSCLC cells treated with cisplatin was increased by secretory OPNc in the condition medium, where reduction of apoptosis by OPNc was associated with the activation of cellular calcium signals and subsequent nuclear translocation of NFATc2.

Conclusions

The results revealed a mechanism of OPN and downstream signal for tumor cells to survive in chemo-stressed TME, which emphasized the importance of secretory proteins in alternative splicing isoforms. Our study not only demonstrated the importance of OPN neutralization for anti-tumor effects, but also implied that modulation in calcium/NFATc2/ROS axis could be a novel approach for improving the long-term outcome of NSCLC treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08495-z.

E-Cadherin expression in human tumors: a tissue microarray study on 10,851 tumors

BACKGROUND

The E-Cadherin gene (CDH1, Cadherin 1), located at 16q22.1 encodes for a calcium-dependent membranous glycoprotein with an important role in cellular adhesion and polarity maintenance.

METHODS

To systematically determine E-Cadherin protein expression in normal and cancerous tissues, 14,637 tumor samples from 112 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types were analyzed by immunohistochemistry in a tissue microarray format.

RESULTS

E-Cadherin was strongly expressed in normal epithelial cells of most organs. From 77 tumor entities derived from cell types normally positive for E-Cadherin, 35 (45.5%) retained at least a weak E-Cadherin immunostaining in ≥99% of cases and 61 (79.2%) in ≥90% of cases. Tumors with the highest rates of E-Cadherin loss included Merkel cell carcinoma, anaplastic thyroid carcinoma, lobular carcinoma of the breast, and sarcomatoid and small cell neuroendocrine carcinomas of the urinary bladder. Reduced E-Cadherin expression was linked to higher grade (p = 0.0009), triple negative receptor status (p = 0.0336), and poor prognosis (p = 0.0466) in invasive breast carcinoma of no special type, triple negative receptor status in lobular carcinoma of the breast (p = 0.0454), advanced pT stage (p = 0.0047) and lymph node metastasis in colorectal cancer (p < 0.0001), and was more common in recurrent than in primary prostate cancer (p < 0.0001). Of 29 tumor entities derived from E-Cadherin negative normal tissues, a weak to strong E-Cadherin staining could be detected in at least 10% of cases in 15 different tumor entities (51.7%). Tumors with the highest frequency of E-Cadherin upregulation included various subtypes of testicular germ cell tumors and renal cell carcinomas (RCC). E-Cadherin upregulation was more commonly seen in malignant than in benign soft tissue tumors (p = 0.0104) and was associated with advanced tumor stage (p = 0.0276) and higher grade (p = 0.0035) in clear cell RCC, and linked to advanced tumor stage (p = 0.0424) and poor prognosis in papillary RCC (p ≤ 0.05).

CONCLUSION

E-Cadherin is consistently expressed in various epithelial cancers. Down-regulation or loss of E-Cadherin expression in cancers arising from E-Cadherin positive tissues as well as E-Cadherin neo-expression in cancers arising from E-Cadherin negative tissues is linked to cancer progression and may reflect tumor dedifferentiation.

Chronic stress promotes EMT-mediated metastasis through activation of STAT3 signaling pathway by miR-337-3p in breast cancer

Chronic stress could induce cancer metastasis by constant activation of the sympathetic nervous system, while cellular mechanism remains obscure. The aim of this research is to explore the metastasis associated negative effect of chronic stress. The analysis of transcriptome sequencing implied that activation of STAT3 signaling pathway by downregulated miR-337-3p might be a potential mechanism to induce epithelial to mesenchymal transition (EMT) of cancer cell and promote metastasis under chronic stress. We also verified this biological process in further experiments. Downregulation of miR-337-3p could downregulate E-cadherin expression and upregulate vimentin expression in vitro and in vivo. STAT3, related signal pathways of which are involved in metastasis regulation, was directly targeted by miR-337-3p. In conclusion, the above results denoted that activation of miR-337-3p/STAT3 axis might be a potential pathway for the increasing metastasis of breast cancer under chronic stress.

Role of regulatory miRNAs of the Wnt/ β-catenin signaling pathway in tumorigenesis of breast cancer

Breast cancer is the most commonly diagnosed malignancy in women worldwide. Recently, uncontrolled expression of microRNAs was detected in several human disorders like cardiovascular, neurological, intestinal and autoimmunity diseases. MicroRNAs (miRNAs) are now investigated as novel prognostic and diagnostic biomarkers for several solid tumors like breast, lung, and gastrointestinal cancers. Current data suggest that miRNAs are implicated in various oncogenic processes implicated in breast cancer carcinogenesis trough modulating canonical Wnt pathway. Aberrant activation of Wnt/b-catenin signaling was shown to be significantly associated with tumor progression and poor prognosis in patients with breast cancer. This review presents recent findings on the molecular mechanism of microRNAs in regulation of Wnt/β-catenin signaling involved in tumorigenesis of breast cancer.

Divergent Effect of Tacalcitol (PRI-2191) on Th17 Cells in 4T1 Tumor Bearing Young and Old Ovariectomized Mice

Vitamin D and its analogs are known for their role in the development of breast cancer and in immunomodulation. Our previous studies have shown the pro-metastatic effect of calcitriol and tacalcitol (PRI-2191) in young mice bearing 4T1 breast cancer and the anti-metastatic effect in aged ovariectomized (OVX) mice. Therefore, the aim of our work was to characterize Th17 cell population in young and aged OVX mice bearing 4T1 tumors treated with calcitriol and PRI-2191. The expression of genes typical for Th17 cells was examined in splenocytes, as well as splenocytes differentiated with IL-6 and TGF-β to Th17 cells (iTh17). Expression of genes encoding vitamin D receptor (Vdr) and osteopontin (Spp1) as well as the secretion of IL-17A were evaluated in iTh17 cells. PRI-2191 treatment increased the expression of Rora and Rorc transcription factors, Il17a, Il17re and Il21 in iTh17 cells from young mice. In aged OVX mice this effect was not observed. Increased expression was observed in the case of Vdr and Spp1 genes in iTh17 cells from young mice treated with PRI-2191. What is more, in young mice treated with PRI-2191 the secretion of IL-17A to the culture media by iTh17 cells was increased, whereas in aged OVX mice a significant decrease was noted. Increased expression of Spp1 in young mice treated with PRI-2191 may enhance the differentiation of Th17 cells.

Enhanced osteopontin splicing regulated by RUNX2 is HDAC-dependent and induces invasive phenotypes in NSCLC cells

Background

Increased cell mobility is a signature when tumor cells undergo epithelial-to-mesenchymal transition. TGF-β is a key stimulating factor to promote the transcription of a variety of downstream genes to accelerate cancer progression and metastasis, including osteopontin (OPN) which exists in several functional forms as different splicing variants. In non-small cell lung cancer cells, although increased total OPN expression was observed under various EMT conditions, the exact constitution and the underlining mechanism towards the generation of such OPN splicing isoforms was poorly understood.

Methods

We investigated the possible mechanisms of osteopontin splicing variant and its role in EMT and cancer metastasis using NSCLC cell line and cell and molecular biology techniques.

Results

In this study, we determined that OPNc, an exon 4 excluded shorter form of Opn gene products, appeared to be more potent to promote cell invasion. The expression of OPNc was selectively increased to higher abundance during EMT following TGF-β induction. The switching from OPNa to OPNc could be enhanced by RUNX2 (a transcription factor that recognizes the Opn gene promoter) overexpression, but appeared to be strictly in a HDAC dependent manner in A549 cells. The results suggested the increase of minor splicing variant of OPNc required both (1) the enhanced transcription from its coding gene driven by specific transcription factors; and (2) the simultaneous modulation or fluctuation of the coupled splicing process that depends to selective classed of epigenetic regulators, predominately HDAC family members.

Conclusion

Our study not only emphasized the importance of splicing variant for its role in EMT and cancer metastasis, but also helped to understand the possible mechanisms of the epigenetic controls for defining the levels and kinetic of gene splicing isoforms and their generations.

Osteopontin as a multifaceted driver of bone metastasis and drug resistance

Metastasis to bone frequently occurs in majority of patients with advanced breast cancer and prostate cancer, leading to devastating skeletal-related events and substantially reducing the survival of patients. Currently, the crosstalk between tumor cells and the bone stromal compartment was widely investigated for bone metastasis and the resistance to many conventional therapeutic methods. Osteopontin (OPN), also known as SPP1 (secreted phosphoprotein 1), a secreted and chemokine-like glyco-phosphoprotein is involved in tumor progression such as cell proliferation, angiogenesis, and metastasis. The expression of OPN in tumor tissue and plasma has been clinically proved to be correlated to poor prognosis and shortened survival in patients with breast cancer and prostate cancer. This review summarizes the multifaceted roles that OPN plays in bone microenvironment and drug resistance, with emphasis on breast and prostate cancers, via binding to αvβ3 integrin and CD44 receptor and inducing signaling cascades. We further discuss the promising therapeutic strategy for OPN targeting, mainly inhibiting OPN at transcriptional or protein level or blocking it binding to receptor or its downstream signaling pathways. The comprehending of the function of OPN in bone microenvironment is crucial for the development of novel biomarker and potential therapeutic target for the diagnosis and treatment of bone metastasis and against the emergence of drug resistance in advanced cancers.

Breast cancer risk in premalignant lesions: osteopontin splice variants indicate prognosis

BACKGROUND

Premalignant breast lesions pose variable risks for transformation, raising the question who should receive treatment to counteract the potential progression to breast cancer. Because the secreted metastasis mediator Osteopontin (OPN) is a marker for breast cancer aggressiveness, its presence in these lesions may reflect progression risk.

METHODS

By immunohistochemistry, we analyse the association of Osteopontin variant expression in healthy breasts, hyperplasias, papillomas, and carcinomas in situ from 434 women to assess a) staining for OPN exon 4 (present in OPN-a and OPN-b) or OPN-c in low-risk to high-risk lesions b) correlations between staining and progression (DCIS with invasion, invasive cancer) or survival.

RESULTS

The markers correlate with risk, and they are prognostic for ensuing invasive disease and survival. About 10% of OPN-c pathology score 0-1 (intensity), vs. 40% of score 3 experience cancer over 5 years. More than 90% of women, who progress, had pathology scores of 2-3 for OPN-c intensity at the time of initial diagnosis. When combining OPN-c and OPN exon 4 staining, all of the low intensity patients are alive after 5 years, whereas women in the high category have a close to 30% chance to die within 5 years. Of patients who succumb, close to 80% had a high combined score at the time of initial diagnosis.

CONCLUSION

The combined information of OPN splice variant immunohistochemistry can provide a foundation for very reliable prognostication and has the potential to aid decision making in the treatment of early breast lesions.

Molecular mechanism of amygdalin action in vitro: review of the latest research

Amygdalin, named as 'laetrile' and 'vitamin B-17' was initially supposed to be a safe drug for cancer treatment and was recognized by followers of natural medicine since it has been considered to be hydrolyzed only in cancer cells releasing toxic hydrogen cyanide (HCN), and thus destroying them. Unfortunately, current studies have shown that HCN is also released in normal cells, therefore it may not be safe for human organism. However, there have still been research works conducted on anti-cancer properties of this compound. In vitro experiments have shown induction of apoptosis by amygdalin as a result of increased expression of Bax protein and caspase-3 and reduced expression of antiapoptotic BcL-2protein. Amygdalin has also been shown to inhibit the adhesion of breast cancer cells, lung cancer cells and bladder cancer cells by decreased expression of integrin's, reduction of catenin levels and inhibition of the Akt-mTOR pathway, which may consequently lead to inhibition of metastases of cancer cells. It has also been revealed that amygdalin in renal cancer cells increased expression of p19 protein resulting in inhibition of cell transfer from G1-phase to S-phase, and thus inhibited cell proliferation. Other studies have indicated that amygdalin inhibits NF-kβ and NLRP3 signaling pathways, and consequently has anti-inflammatory effect due to reducing the expression of proinflammatory cytokines such as pro-IL-1β. Moreover, the effect of amygdalin on TGFβ/CTGF pathway, anti-fibrous activity and expression of follistatin resulting in activation of muscle cells growth has been reported. This compound might be applicable in the treatment of various cancer cell types.

Overexpression of osteopontin promotes cell proliferation and migration in human nasopharyngeal carcinoma and is associated with poor prognosis

Nasopharyngeal carcinoma (NPC), a malignant tumor at the top and side of the nasopharyngeal cavity, highly occurs in the southern region of China. Cancer cell metastasis is one of the leading causes of death in NPC patients. Osteopontin (OPN), is a phosphorylated extracellular matrix protein with a variety of functions, was found to be overexpressed in many cancers. However, the expression and role of OPN in patients with NPC in Guangxi, China are unclear. Here, we observed that NPC patients had upregulated OPN at mRNA protein and levels. Immunochemistry (IHC) analysis of OPN expression in 68 NPC clinical specimens indicated that high expression of OPN had positive correlation with NPC lymph node metastasis (P = 0.012), distant metastasis (P = 0.001) and TNM staging (P = 0.018). Moreover, compared with relatively low OPN, NPC patients with higher expression of OPN showed a poorer overall survival rate (P = 0.001, log rank test). Multivariate analysis showed that OPN expression in NPC was an independent prognostic marker. The proliferation, apoptosis and migration ability of CEN-2Z cancer cells in NPC were determined by MTT, flow cytometry and wound-healing assays, respectively. Upregulation of OPN in CEN-2Z cancer cells promoted cancer cell proliferation and migration, and suppressed apoptosis. In sum, our result suggests OPN could be used as a valuable oncoprotein and show that overexpression of OPN in NPC may serve as a potential prognostic marker.

Unfavorable effect of calcitriol and its low-calcemic analogs on metastasis of 4T1 mouse mammary gland cancer

Low vitamin D status is considered as a risk factor for breast cancer and has prognostic significance. Furthermore, vitamin D deficiency increases after adjuvant cancer therapy, which alters bone metabolism increasing the risk of osteoporosis. It is now postulated that vitamin D supplementation in breast cancer treatment delays the recurrence of cancer thereby extending survival. We evaluated the impact of calcitriol and its low-calcemic analogs, PRI-2191 and PRI-2205, on the tumor growth, angiogenesis, and metastasis of 4T1 mouse mammary gland cancer. Gene expression analysis related to cancer invasion/metastasis, real-time PCR, ELISA, western blotting, and histochemical studies were performed. In vitro studies were conducted to compare the effects of calcitriol and its analogs on 4T1 and 67NR cell proliferation and expression of selected proteins. Calcitriol and its analogs increased lung metastasis without influencing the growth of primary tumor. The levels of plasma 17β-estradiol and transforming growth factor β (TGFβ) were found to be elevated after treatment. Moreover, the results showed that tumor blood perfusion improved and osteopontin (OPN) levels increased, whereas vascular endothelial growth factor (VEGF) and TGFβ levels decreased in tumors from treated mice. All the studied treatments resulted in increased collagen content in the tumor tissue in the early step of tumor progression, and calcitriol caused an increase in collagen content in lung tissue. In addition, in vitro proliferation of 4T1 tumor cells was not found to be affected by calcitriol or its analogs in contrast to non-metastatic 67NR cells. Calcitriol and its analogs enhanced the metastatic potential of 4T1 mouse mammary gland cancer by inducing the secretion of OPN probably via host cells. In addition, OPN tumor overexpression prevailed over the decreasing tumor TGFβ level and blood vessel normalization via tumor VEGF deprivation induced by calcitriol and its analogs. Moreover, the increased plasma TGFβ and 17β-estradiol levels contributed to the facilitation of metastatic process.

Expression analysis of E-cad and vascular endothelial growth factor in triple-negative breast cancer patients of different ethnic groups in western China

The aim of this article is to investigate the expression of E-cadherin (E-cad) and vascular endothelial growth factor (VEGF) in triple-negative breast cancer (TNBC) of Han and Uygur women patients in western China, and their relationship with clinical features of TNBC.Totally, 172 cases of Han TNBC patients and 79 cases of Uighur TNBC patients were enrolled. The expressions of E-cad and VEGF were detected with immunohistochemistry. The correlation of E-cad and VEGF expression with lymph node metastasis, TNM stage, and histological grade were analyzed. The 5-year disease-free survival rate of the 2 groups was also evaluated.There was no significant difference in the 5-year disease-free survival rate (P > .05) and the expression of E-cad between the 2 groups. The positive rate of VEGF in Han was significantly lower than that in Uygur (P < .05). The expression of E-cad was negatively correlated with lymph node metastasis, TNM stage, and histological grade (-1≤r < 1, P < .05). However, the expression of VEGF was positively correlated with lymph node metastasis and TNM staging (0 < r < 1, P < 0.05), but not with histological grading.The expression of E-cad and VEGF and their relationship with clinical features of TNBC suggest that Uygur TNBC patients might have different prognostic factors as compared with Han patients.

Prognostic value of reduced E-cadherin expression in breast cancer: a meta-analysis

The prognostic value of E-cadherin expression in patients with breast cancer has been studied for years, yet results remain controversial. We thus performed a comprehensive evaluation of the association between E-cadherin expression and prognosis through a meta-analysis. The databases PubMed, Embase and Cochrane Library were searched. A total of 7,353 patients from 33 studies were subject to final analysis. The results showed there was a significant association between reduced expression of E-cadherin and overall survival (OS) (HR 1.79, 95% CI 1.41–2.27) and disease-free survival (DFS) (HR 1.62, 95% CI 1.31–1.99) in breast cancer. Downregulated expression of E-cadherin significantly correlated with tumor histological grade (OR 1.44, 95% CI 1.06–1.96), TNM stage (OR 2.44, 95% CI 1.75–3.41), tumor size (OR 1.38, 95% CI 1.18–1.60), lymph node status (OR 1.55, 95% CI 1.15–2.10), and progesterone receptor status (OR 1.44, 95% CI 1.10–1.88).This meta-analysis suggested that reduced E-cadherin expression might be a predictor of a poorer prognosis and could be a potentially new gene therapy target for breast cancer patients.

E-cadherin expression phenotypes associated with molecular subtypes in invasive non-lobular breast cancer: evidence from a retrospective study and meta-analysis

Background

This retrospective study and meta-analysis was designed to explore the relationship between E-cadherin (E-cad) expression and the molecular subtypes of invasive non-lobular breast cancer, especially in early-stage invasive ductal carcinoma (IDC).

Methods

A total of 156 post-operative cases of early-stage IDCs were retrospectively collected for the immunohistochemistry (IHC) detection of E-cad expression. The association of E-cad expression with molecular subtypes of early-stage IDCs was analyzed. A literature search was conducted in March 2016 to retrieve publications on E-cad expression in association with molecular subtypes of invasive non-lobular breast cancer, and a meta-analysis was performed to estimate the relational statistics.

Results

E-cad was expressed in 82.7% (129/156) of early-stage IDCs. E-cad expression was closely associated with the molecular types of early-stage IDCs (P < 0.050); moreover, the molecular subtypes were an independent factor influencing E-cad expression in early-stage IDCs. A total of 12 observational studies (including our study) were included in the meta-analysis. The meta-analytical results show a significantly greater risk of E-cad expression loss in triple-negative breast cancer (TNBC) than in other molecular subtypes (TNBC vs. luminal A: RR = 3.45, 95% CI = 2.79–4.26; TNBC vs. luminal B: RR = 2.41, 95% CI = 1.49–3.90; TNBC vs. HER2-enriched: RR = 1.95, 95% CI = 1.24–3.07).

Conclusions

Early-stage IDCs or invasive non-lobular breast cancers with the TNBC molecular phenotype have a higher risk for the loss of E-cad expression than do tumors with non-TNBC molecular phenotypes, suggesting that E-cad expression phenotypes were closely related to molecular subtypes and further studies are needed to clarify the underlying mechanism.

Electronic supplementary material

The online version of this article (doi:10.1186/s12957-017-1210-8) contains supplementary material, which is available to authorized users.

Human osteopontin: Potential clinical applications in cancer (Review)

Human osteopontin (OPN) is a glycosylated phosphoprotein which is expressed in a variety of tissues in the body. In recent years, accumulating evidence has indicated that the aberrant expression of OPN is closely associated with tumourigensis, progression and most prominently with metastasis in several tumour types. In this review, we present the current knowledge on the expression profiles of OPN and its main splice variants in human cancers, as well as the potential implications in patient outcome. We also discuss its putative clinical application as a cancer biomarker and as a therapeutic target.

Osteopontin splice variants and polymorphisms in cancer progression and prognosis

Osteopontin (OPN) is an extracellular matrix protein that is overexpressed in various cancers and promotes oncogenic features including cell proliferation, survival, migration, and angiogenesis, among others. OPN can participate in the regulation of the tumor microenvironment, affecting both cancer and neighboring cells. Here, we review the roles of OPN splice variants (a, b, c) in cancer development, progression, and prognosis, and also discuss the identities of isoforms 4 and 5. We also discussed how single-nucleotide polymorphisms (SNPs) of the OPN gene are an additional factor influencing the level of OPN in individuals, modulating the risks of cancer development and outcome.

Association of osteopontin with specific prognostic factors and survival in adjuvant breast cancer trials of the Hellenic Cooperative Oncology Group

BACKGROUND

The shift towards an earlier diagnosis of breast cancer (BC) highlights the need for biomarkers that would identify patients at risk for relapse and metastatic spread and indicate the potential value of additional treatment strategies. Osteopontin (OPN) is a matricellular protein that has been suggested to be a potential biomarker in BC. In the present study, we used archived BC patient samples to assess the clinical utility of OPN.

METHODS

Formalin-fixed paraffin-embedded tumor tissue samples from 975 patients were collected from two large phase III randomized adjuvant chemotherapy trials (HE10/97 and HE10/00) that included patients with high risk BC. All tissue samples were assessed for ER, PgR, Ki67 and HER2 protein expression. OPN protein and mRNA expression was evaluated using immunohistochemistry and quantitative reverse transcription-polymerase chain reaction, respectively.

RESULTS

OPN mRNA expression data were available for 814 patients, whereas OPN protein expression data were available for 546 patients. The majority of patients were ER/PgR-positive (78.3%), HER2-negative (76.5%) and Ki67-positive (55.2%) and had received adjuvant radiation therapy (76.8%) and hormonal therapy (81.1%). OPN mRNA expression was significantly associated with age (60.9% in high OPN tumors vs. 54.1% in low OPN tumors, p = 0.047), ER/PgR-negative status (25.7 vs. 17.2%, p = 0.004) and BC subtypes (p = 0.021). In addition, high OPN mRNA expression was significantly associated with reduced DFS (HR 1.26, 95% CI 1.00-1.59, Wald's p = 0.050) and OS (HR 1.37, 95% CI 1.05-1.78, p = 0.019), while it retained its prognostic significance for both DFS (HR 1.39, 95% CI 1.10-1.77, p = 0.007) and OS (HR 1.54, 95% CI 1.61-2.05, p = 0.003) in the multivariate analysis.

CONCLUSIONS

We showed that high OPN mRNA expression is associated with decreased DFS and OS in a large cohort of BC patients treated with adjuvant chemotherapy in a clinical trial setting. Our results suggest that OPN may serve as a prognostic factor and a potential target for therapy. Trial registration Australian New Zealand Clinical Trials Registry; HE10/97 ACTRN12611000506998; HE10/00 ACTRN12609001036202.

Current status of the prognostic molecular biomarkers in breast cancer: A systematic review

Biomarkers that facilitate the prediction of breast cancer prognosis can improve the quality of life in patients during the long period of illness and treatment. Particularly in recent years, with the advent of a more exhaustive analysis of genetic information and gene products, the molecular mechanisms at play during breast cancer have gradually become clearer. In the present study, a systematic review of the literature between 2009 and 2014 was conducted by searching for the keywords 'breast cancer', 'biomarkers', 'diagnosis', 'prognosis' and 'drug response' to clarify the present state of knowledge regarding biomarkers. In the final analysis, 16 studies on biomarkers for the breast cancer prognosis were retrieved. From these, 7 biomarkers in 9 studies were found to be strongly reliable predictors of prognosis and a further 7 biomarkers in 7 studies were poorly reliable. The use of these prognostic biomarkers should increase the options available for treatment algorithms.

Prognostic Value of E-Cadherin and β-Catenin in Triple-Negative Breast Cancer

OBJECTIVES

To analyze the expression of E-cadherin and β-catenin in triple-negative breast cancer (TNBC) to assess their prognostic significance.

METHODS

The expression of E-cadherin and β-catenin was examined semiquantitatively and correlated with other pathologic factors and survival outcomes.

RESULTS

Of 72 consecutive TNBCs, 56% showed reduced membranous expression of E-cadherin or β-catenin, with a strong correlation to each other. Of the clinicopathologic factors analyzed, tumor size and nodal status were significantly associated with overall survival and disease-specific survival, while the latter remained an independent factor by multivariate analysis. Reduced E-cadherin and β-catenin were both significantly associated with a poor overall survival and disease-specific survival by univariate and multivariate analyses.

CONCLUSIONS

E-cadherin and β-catenin expression provides discriminative prognostic power independent of conventional pathologic factors, thus further reinforcing the important role of cell adhesion molecules in the process of tumor metastasis, especially in TNBC.

Role of osteopontin in lung cancer evolution and heterogeneity

Patients with lung cancer still have high mortality, recurrence rate after adjuvant treatment, and poor five-year survival rates, despite of advances in multidisciplinary anti-cancer therapies, e.g. chemotherapy, radiotherapy and targeted therapies, It depends upon the presence of intratumoral heterogeneity and complexity of lung cancer. There is growing evidence to suggest that osteopontin (OPN) may play a critical role in tumor progression and metastasis. The present review briefly describes the structure and molecular biology of OPN, highlights the role of OPN in the development and metastasis of lung cancer, and summarizes potential mechanisms of OPN heterogeneity in tumor to underline some of these inconsistencies. The article will emphasize the importance to understand the role of OPN in cancer evolution and heterogeneity and explore the potential of OPN as a therapeutic target.

Prognostic Value of Osteopontin Splice Variant-c Expression in Breast Cancers: A Meta-Analysis

Objectives. Osteopontin (OPN) is overexpressed in breast cancers, while its clinical and prognostic significance remained unclear. This study aimed to assess the prognostic value of OPN, especially its splice variants, in breast cancers. Methods. Data were extracted from eligible studies concerning the OPN and OPN-c expression in breast cancer patients and were used to calculate the association between OPN/OPN-c and survival. Two reviewer teams independently screened the literatures according to the inclusion and exclusion criteria based on quality evaluation. Following the processes of data extraction, assessment, and transformation, meta-analysis was carried out via RevMan 5.3 software. Results. A total of ten studies involving 1,567 patients were included. The results demonstrated that high level OPN indicated a poor outcome in the OS (HR = 2.22, 95% CI: 1.23–4.00, and P = 0.008; random-effects model) with heterogeneity (I² = 62%) of breast cancer patients. High level OPN-c appeared to be more significantly associated with poor survival (HR = 2.14, 95% CI: 1.51–3.04, and P < 0.0001; fixed-effects model) with undetected heterogeneity (I² = 0%). Conclusions. Our analyses indicated that both OPN and OPN-c could be considered as prognostic markers for breast cancers. The high level of OPN-c was suggested to be more reliably associated with poor survival in breast cancer patients.

Mathematical Modelling of Molecular Pathways Enabling Tumour Cell Invasion and Migration

Understanding the etiology of metastasis is very important in clinical perspective, since it is estimated that metastasis accounts for 90% of cancer patient mortality. Metastasis results from a sequence of multiple steps including invasion and migration. The early stages of metastasis are tightly controlled in normal cells and can be drastically affected by malignant mutations; therefore, they might constitute the principal determinants of the overall metastatic rate even if the later stages take long to occur. To elucidate the role of individual mutations or their combinations affecting the metastatic development, a logical model has been constructed that recapitulates published experimental results of known gene perturbations on local invasion and migration processes, and predict the effect of not yet experimentally assessed mutations. The model has been validated using experimental data on transcriptome dynamics following TGF-β-dependent induction of Epithelial to Mesenchymal Transition in lung cancer cell lines. A method to associate gene expression profiles with different stable state solutions of the logical model has been developed for that purpose. In addition, we have systematically predicted alleviating (masking) and synergistic pairwise genetic interactions between the genes composing the model with respect to the probability of acquiring the metastatic phenotype. We focused on several unexpected synergistic genetic interactions leading to theoretically very high metastasis probability. Among them, the synergistic combination of Notch overexpression and p53 deletion shows one of the strongest effects, which is in agreement with a recent published experiment in a mouse model of gut cancer. The mathematical model can recapitulate experimental mutations in both cell line and mouse models. Furthermore, the model predicts new gene perturbations that affect the early steps of metastasis underlying potential intervention points for innovative therapeutic strategies in oncology.

Overexpression of osteopontin promotes resistance to cisplatin treatment in HCC

Osteopontin (OPN) is a multi-functional cytokine involved in cell survival, migration and adhesion. Increasing evidence has elucidated its role in tumorigenesis, progression and metastasis. However, the role of OPN in chemoresistance of human hepatocellular carcinoma (HCC) has not yet been clarified. In the present study, we examined the expression of OPN in human HCC samples before and after cisplatin-treatment, the results showed that OPN was significantly increased in cisplatin-resistant specimens. We then studied the effect of cisplatin on OPN expression in HCC cells, after exposure to cisplatin, the expression of OPN in HCC cells was elevated compared to control cells. We also found that PI3K/AKT signaling pathway was also activated by cisplatin and this effect was induced by the OPN pathway. To study the effect of OPN on chemoresistance, HCC cells were treated with cisplatin along with OPN. Incubation with OPN enchanced the chemoresistance of HCC cells to cisplatin. In contrast, blockage of OPN pathway promoted the chemosensitivity of HCC cells to cisplatin. Our results suggest that OPN enhanced chemoresistance of cisplatin in HCC cells by activating PI3K/AKT signaling pathway, blocking the OPN pathway might be a novel way to overcome the disease.

Immunohistochemical assessment of E-cadherin and β-catenin in the histological differentiations of oral squamous cell carcinoma

The aim of this study was to establish the expression and localization of E-cadherin and β-catenin in oral squamous cell carcinomas (OSCC) so that we could correlate the findings with prognostic-relevant histopathological variables. E-cadherin and β-catenin expression in normal oral epithelia and in oral squamous cell carcinomas was examined immunohistochemically, and associations with histopathological differentiation and prognosis were then analyzed in 33 patients who had been operated on for OSCC. E-cadherin expression was found in (82%) of the squamous cells of well differentiated OSCC, (61%) of moderately differentiated and (39%) of poorly differentiated. E-cadherin expression was significantly associated with histological grade (p=0.000). No nuclear staining was detected. In (19.5%) of the cells E-cadherin localized in the cytoplasm, with no correlation to the histological grade (p=0.106). β-Catenin expression was found in 87% of the squamous cells of well differentiated OSCC, 67% of moderately differentiated and 43% of poorly differentiated, the expression was significantly associated with histological grade (p=0.000). the nuclear β-Catenin expression appeared in 3.3% of the cells and it was correlated to the histological grade (p=0.000). In (23.5%) of the cells β-Catenin localized in the cytoplasm, with correlation to the histological grade (p=0.002). According to this study the expression of β-catenin and E-cadherin were independent prognostic factors for histological grade. E-cadherin was closely linked to β-catenin expression in OSCC (p=0.000) and to tumor differentiation. That reflects a structural association and the role of both in tumor progression.

Nuclear osteopontin-c is a prognostic breast cancer marker

BACKGROUND

Although Osteopontin has been known as a marker for cancer progression, the elevated production of this cytokine is not specific for cancer. We have identified the splice variant Osteopontin-c as being absent from healthy tissue but associated with about 75% of breast cancer cases. However, in previous studies of Osteopontin-c, follow-up information was not available.

METHODS

Here we have analysed 671 patients, comprising a cohort of 291 paraffin blocks plus a population-based case-control study of 380 arrayed breast tumor tissues.

RESULTS

We find that high staining intensity of nuclear Osteopontin-c is strongly associated with mortality in patients with early breast cancer. Cytosolic staining for exon 4, reflective of Osteopontin-a and -b also predicts poor outcome. By contrast, total Osteopontin does not correlate with prognosis. These diverse assessments of Osteopontin also do not correlate with each other, suggesting distinct expression patterns for the variant forms. Consistent with its role in tumor progression, not tumor initiation, Osteopontin-c is not correlated with proliferation markers (Ki-67, cyclin A, cyclin B, cyclin E and cyclin D), neither is it correlated with ER, PR or HER2.

CONCLUSIONS

The addition of Osteopontin-c immunohistochemistry to standard pathology work-ups may have prognostic benefit in early breast cancer diagnosis.

Pin1-based diagnostic and therapeutic strategies for breast cancer

Pin1 is the only known cis-to-trans isomerase that recognizes the phosphorylated pThr/pSer-Pro motifs in many signaling molecules, playing unique roles in the pathogenesis of breast cancer. First, Pin1 is prevalently over-expressed in kinds of breast cancer cell lines and tissues, such as MDA-MB-231 cell, MCF-7 cell, Her2+, ERα+, and basal-like breast cancer subtypes. Second, Pin1 amplifies many oncogenic signaling pathways, inhibits multiple tumor suppressors, promotes the angiogenesis and metastasis of breast cancer cells, and enhances the resistance of breast cancer cells to anti-tumor medicines. Third, inhibiting Pin1 blocks most of these detrimental effects in a great number of breast cancer cell lines. These findings suggest Pin1 as a promising diagnostic biomarker as well as an efficient therapeutic target for breast cancer. It is strongly expected that a Pin1-positive subtype of breast cancers should be extremely concerned and that the therapeutic efficacy of Pin1 inhibitors on breast cancer patients should be evaluated as soon as possible. Nonetheless, Pin1-based therapeutic strategies for breast cancer still deserve some debates. Hence, we give the predictions of several important issues, such as application precondition, side effects, and personalized medication, when Pin1 inhibitors are used in the breast cancer therapy. These proposals are meaningful for the further development of Pin1-based diagnostic and therapeutic strategies in order to conquer breast cancer.

Osteopontin mediates an MZF1-TGF-β1-dependent transformation of mesenchymal stem cells into cancer-associated fibroblasts in breast cancer

Interactions between tumor cells and cancer-associated fibroblasts (CAFs) in the tumor microenvironment (TMEN) significantly influence cancer growth and metastasis. Transforming growth factor-β (TGF-β) is known to be a critical mediator of the CAF phenotype, and osteopontin (OPN) expression in tumors is associated with more aggressive phenotypes and poor patient outcomes. The potential link between these two pathways has not been previously addressed. Utilizing in vitro studies using human mesenchymal stem cells (MSCs) and MDA-MB231 (OPN+) and MCF7 (OPN−) human breast cancer cell lines, we demonstrate that OPN induces integrin-dependent MSC expression of TGF-β1 to mediate adoption of the CAF phenotype. This OPN-TGF-β1 pathway requires the transcription factor, myeloid zinc finger 1 (MZF1). In vivo studies with xenotransplant models in NOD-scid mice showed that OPN expression increases cancer growth and metastasis by mediating MSC-to-CAF transformation in a process that is MZF1- and TGF-β1-dependent. We conclude that tumor-derived OPN engenders MSC-to-CAF transformation in the microenvironment to promote tumor growth and metastasis via the OPN-MZF1-TGF-β1 pathway.

Prognostic value of osteopontin expression in breast cancer: A meta-analysis

Osteopontin (OPN) has been implicated in tumor development and progression over the last few years. However, the prognostic value of OPN overexpression in patients with breast cancer remains controversial. We performed a meta-analysis to investigate the association of OPN expression in the tumor with the clinicopathological characteristics and survival of breast cancer patients. A total of 8 studies met the inclusion criteria and were entered in the meta-analysis. The data analysis demonstrated that OPN expression was positively associated with lymph node metastasis [pooled odds ratio = 2.026, 95% confidence interval (CI): 1.199-3.425, P=0.008, random-effects model]. We also found that OPN expression was positively associated with overall survival [hazard ratio (HR) = 3. 69, 95% CI: 1. 45-9.42, P=0.000, random-effects model) and disease -free survival (pooled HR=2.40, 95% CI: 1.27-4.55, P=0.007, fix ed -effects model). Based on the results of this study, we concluded that OPN overexpression in the tumor is a candidate positive prognostic biomarker for breast cancer patients.

Far beyond the usual biomarkers in breast cancer: a review

Research investigating biomarkers for early detection, prognosis and the prediction of treatment responses in breast cancer is rapidly expanding. However, no validated biomarker currently exists for use in routine clinical practice, and breast cancer detection and management remains dependent on invasive procedures. Histological examination remains the standard for diagnosis, whereas immunohistochemical and genetic tests are utilized for treatment decisions and prognosis determinations. Therefore, we conducted a comprehensive review of literature published in PubMed on breast cancer biomarkers between 2009 and 2013. The keywords that were used together were breast cancer, biomarkers, diagnosis, prognosis and drug response. The cited references of the manuscripts included in this review were also screened. We have comprehensively summarized the performance of several biomarkers for diagnosis, prognosis and predicted drug responses of breast cancer. Finally, we have identified 15 biomarkers that have demonstrated promise in initial studies and several miRNAs. At this point, such biomarkers must be rigorously validated in the clinical setting to be translated into clinically useful tests for the diagnosis, prognosis and prediction of drug responses of breast cancer.

Role of osteopontin in the pathophysiology of cancer

Osteopontin (OPN) is a multifunctional cytokine that impacts cell proliferation, survival, drug resistance, invasion, and stem like behavior. Due to its critical involvement in regulating cellular functions, its aberrant expression and/or splicing is functionally responsible for undesirable alterations in disease pathologies, specifically cancer. It is implicated in promoting invasive and metastatic progression of many carcinomas. Due to its autocrine and paracrine activities OPN has been shown to be a crucial mediator of cellular cross talk and an influential factor in the tumor microenvironment. OPN has been implicated as a prognostic and diagnostic marker for several cancer types. It has also been explored as a possible target for treatment. In this article we hope to provide a broad perspective on the importance of OPN in the pathophysiology of cancer.