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

TSP50 facilitates breast cancer stem cell-like properties maintenance and epithelial-mesenchymal transition via PI3K p110α mediated activation of AKT signaling pathway

BACKGROUND

Studies have confirmed that epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC)-like properties are conducive to cancer metastasis. In recent years, testes-specific protease 50 (TSP50) has been identified as a prognostic factor and is involved in tumorigenesis regulation. However, the role and molecular mechanisms of TSP50 in EMT and CSC-like properties maintenance remain unclear.

METHODS

The expression and prognostic value of TSP50 in breast cancer were excavated from public databases and explored using bioinformatics analysis. Then the expression of TSP50 and related genes was further validated by quantitative RT-PCR (qRT-PCR), Western blot, and immunohistochemistry (IHC). In order to investigate the function of TSP50 in breast cancer, loss- and gain-of-function experiments were conducted, both in vitro and in vivo. Furthermore, immunofluorescence (IF) and immunoprecipitation (IP) assays were performed to explore the potential molecular mechanisms of TSP50. Finally, the correlation between the expression of TSP50 and related genes in breast cancer tissue microarray and clinicopathological characteristics was analyzed by IHC.

RESULTS

TSP50 was negatively correlated with the prognosis of patients with breast cancer. TSP50 promoted CSC-like traits and EMT in both breast cancer cells and mouse xenograft tumor tissues. Additionally, inhibition of PI3K/AKT partly reversed TSP50-induced activation of CSC-like properties, EMT and tumorigenesis. Mechanistically, TSP50 and PI3K p85α regulatory subunit could competitively interact with the PI3K p110α catalytic subunit to promote p110α enzymatic activity, thereby activating the PI3K/AKT signaling pathway for CSC-like phenotypes maintenance and EMT promotion. Moreover, IHC analysis of human breast cancer specimens revealed that TSP50 expression was positively correlated with p-AKT and ALDH1 protein levels. Notably, breast cancer clinicopathological characteristics, such as patient survival time, tumor size, Ki67, pathologic stage, N stage, estrogen receptor (ER) and progesterone receptor (PR) levels, correlated well with TSP50/p-AKT/ALDH1 expression status.

CONCLUSION

The effects of TSP50 on EMT and CSC-like properties promotion were verified to be dependent on PI3K p110α. Together, our study revealed a novel mechanism by which TSP50 facilitates the progression of breast cancer, which can provide new insights into TSP50-based breast cancer treatment strategies.

GALNT6, GALNT14, and Gal-3 in association with GDF-15 promotes drug resistance and stemness of breast cancer via β-catenin axis

N-acetylgalactosaminyltransferases (GALNTs) are a polypeptide responsible for aberrant glycosylation in breast cancer (BC), but the mechanism is unclear. In this study, expression levels of GALNT6, GALNT14, and Gal-3 were assessed in BC, and their association with GDF-15, β-catenin, stemness (SOX2 and OCT4), and drug resistance marker (ABCC5) was evaluated. Gene expression of GALNT6, GALNT14, Gal-3, GDF-15, OCT4, SOX2, ABCC5, and β-catenin in tumor and adjacent non-tumor tissues (n = 30) was determined. The same was compared with GEO-microarray datasets. A significant increase in the expression of candidate genes was observed in BC tumor compared to adjacent non-tumor tissue; and in pre-therapeutic patients compared to post-therapeutic. GALNT6, GALNT14, Gal-3, and GDF-15 showed positive association with β-catenin, SOX2, OCT4, and ABCC5 and were significantly associated with poor Overall Survival. Our findings were also validated via in silico analysis. Our study suggests that GALNT6, GALNT14, and Gal-3 in association with GDF-15 promote stemness and intrinsic drug resistance in BC, possibly by β-catenin signaling pathway.

Impact of immunohistochemical expression of kinesin family member 18A (Kif18A) and β-catenin in infiltrating breast carcinoma of no special type

BACKGROUND

KIF18A is a regulator of the cell cycle that stimulates the proliferation of cancer cells. The Wnt/β-catenin pathway is involved in different issues' carcinogenesis and is being examined as a therapeutic target. The relationship between KIF18A and β-catenin in breast cancer was not previously investigated. Therefore, this work aims to study the immunohistochemical expression and correlation of KIF18A and β-catenin in breast-infiltrating duct carcinoma (IDC) and their relation to prognosis.

MATERIAL AND METHODS

Slides cut from paraffin blocks of 135 IDC and 40 normal breast tissues were stained by KIF18A and β-catenin antibodies. KIF18A cytoplasmic or nucleocytoplasmic staining and β-catenin aberrant expression either nucleo-cytoplasmic or cytoplasmic staining were considered.

RESULTS

Normal breast tissue and IDC showed a significant difference regarding KIF18A and aberrant β-catenin expression. High KIF18A and β-catenin H score values were associated with poor prognostic factors such as high grade, advanced stage, distant metastasis, high Ki67 status, and Her2neu-enriched subtype. There was a significant direct correlation between KIF18A and β-catenin as regards percent and H score values. Prolonged overall survival (OS) was significantly associated with mild intensity and low H score of KIF18A, and low β-catenin H score.

CONCLUSIONS

KIF18A could be involved in breast carcinogenesis by activating β-catenin. Overexpression of KIF18A and aberrant expression of β-catenin are considered proto-oncogenes of breast cancer development. KIF18A and β-catenin could be poor prognostic markers and predictors of aggressive behavior of breast cancer.

The Effect of Adipocyte-Secreted Factors in Activating Focal Adhesion Kinase-Mediated Cell Signaling Pathway towards Metastasis in Breast Cancer Cells

Obesity-associated perturbations in the normal secretion of adipocytokines from white adipocytes can drive the metastatic progression of cancer. However, the association between obesity-induced changes in secretory factors of white adipocytes and subsequent transactivation of the downstream effector proteins impacting metastasis in breast cancer cells remains unclear. Focal adhesion kinase, a cytoplasmic signal transducer, regulates the biological phenomenon of metastasis by activating downstream targets such as beta-catenin and MMP9. Thus, the possible role of phosphorylated FAK in potentiating cancer cell migration was investigated. To elucidate this potential relationship, MCF7 (ER+), MDA-MB-231 (Triple Negative) breast cancer cells, and MCF-10A non-tumorigenic breast cells were exposed to in vitro murine adipocyte-conditioned medium derived from 3T3-L1 MBX cells differentiated to obesity with fatty acid supplementation. Our results show that the conditioned medium derived from these obese adipocytes enhanced motility and invasiveness of breast cancer cells. Importantly, no such changes were observed in the non-tumorigenic breast cells. Our results also show that increased FAK autophosphorylation was followed by increased expression of beta-catenin and MMP9 in the breast cancer cells when exposed to obese adipocyte-conditioned medium, but not in the MCF10A cells. These results indicate that adipocyte-derived secretory factors induced FAK activation through phosphorylation. This in turn increased breast cancer cell migration and invasion by activating its downstream effector proteins beta-catenin and MMP9.

Synthesis and Antitumor Activity of Brominated-Ormeloxifene (Br-ORM) against Cervical Cancer

Aberrant regulation of β-catenin signaling is strongly linked with cancer proliferation, invasion, migration, and metastasis, thus, small molecules that can inhibit this pathway might have great clinical significance. Our molecular modeling studies suggest that ormeloxifene (ORM), a triphenylethylene molecule that docks with β-catenin, and its brominated analogue (Br-ORM) bind more effectively with relatively less energy (-7.6 kcal/mol) to the active site of β-catenin as compared to parent ORM. Herein, we report the synthesis and characterization of a Br-ORM by NMR and FTIR, as well as its anticancer activity in cervical cancer models. Br-ORM treatment effectively inhibited tumorigenic features (cell proliferation and colony-forming ability, etc.) and induced apoptotic death, as evident by pronounced PARP cleavage. Furthermore, Br-ORM treatment caused cell cycle arrest at the G1-S phase. Mechanistic investigation revealed that Br-ORM targets the key proteins involved in promoting epithelial-mesenchymal transition (EMT), as demonstrated by upregulation of E-cadherin and repression of N-cadherin, Vimentin, Snail, MMP-2, and MMP-9 expression. Br-ORM also represses the expression and nuclear subcellular localization of β-catenin. Consequently, Br-ORM treatment effectively inhibited tumor growth in an orthotopic cervical cancer xenograft mouse model along with EMT associated changes as compared to vehicle control-treated mice. Altogether, experimental findings suggest that Br-ORM is a novel, promising β-catenin inhibitor and therefore can be harnessed as a potent anticancer small molecule for cervical cancer treatment.

Resveratrol exhibits diverse anti-cancer activities through epigenetic regulation of E-cadherin and p21 in triple-negative breast cancer cells

BACKGROUND

Triple-negative breast cancer (TNBC) has an aggressive phenotype and poor outcome, however no specific targeted therapy has been established for TNBC lacking germline BRCA1/2 pathogenic variants. To develop a novel therapeutic strategy, we explored the potential of resveratrol (RSV) for TNBC treatment.

METHODS

We investigated the effects of RSV on malignant phenotypes of TNBC cells as well as on apoptosis induced by ABT263, a specific inhibitor of BCL-2 and BCL-xL, using morphological observation, migration assay, β-galactosidase staining, and Hoechst staining. To elucidate the underlying mechanisms of RSV-mediated effects, expression levels and histone acetylation levels of cadherin 1 (CDH1, E-cadherin) and cyclin dependent kinase inhibitor 1A (CDKN1A, p21) were determined by RT-qPCR, western blotting, and chromatin immunoprecipitation. Furthermore, knockdown analysis was conducted to evaluate the involvement of E-cadherin and/or p21 in RSV potentiation on cytotoxic activity of ABT263.

RESULTS

RSV treatment induced epithelial-like cellular morphology and suppressed the migration capacity in MDA-MB-231 and BT-549-Luc TNBC cells. β-galactosidase-positive cells were increased after RSV treatment, indicating the induction of cellular senescence, in MDA-MB-231 cells but not in BT-549-Luc cells. RSV increased the expression and histone acetylation of CDH1 and CDKN1A in both cells. Interestingly, pre-treatment with RSV enhanced the induction of apoptosis in the ABT263-treated MDA-MB-231 and BT-549-Luc cells, and knockdown of CDKN1A decreased ABT263-induced apoptosis in RSV-treated MDA-MB-231 cells.

CONCLUSIONS

RSV represses the metastatic capacity and enhances the cytotoxic activity of ABT263 in TNBC cells. Our results suggested that RSV can potentially be used as a repressor of metastasis or a sensitizer to ABT263 for TNBC treatment via up-regulation of CDH1 and CDKN1A through epigenetic mechanisms.

Differential expression levels of β-catenin are associated with invasive behavior of both functional and non-functional pituitary neuroendocrine tumor (PitNET)

BACKGROUND

Although research continues to elucidate the molecular mechanism underlying pituitary tumor pathogenesis, limited information is available on the potential role and expression profile of β-catenin in functional and non-functional pituitary neuroendocrine tumors (PitNETs).

METHODS AND RESULTS

In the current study, 104 pituitary samples (tumors and cadaveric healthy pituitary tissues) were included and the gene and protein expression levels of β-catenin were assessed by Real-Time PCR and immunohistochemistry, respectively. The correlation between expression level of β-catenin and tumor invasive feature and size as well as patient age, gender, and hormonal level was measured. The data showed that PitNET samples expressed higher levels of the β-catenin gene and protein compared to healthy pituitary tissues. Although there was no difference in β-catenin expression level between non-functioning (NF-PitNETs) and growth hormone-producing tumors (GH-PitNETs), both tumor types showed significantly elevated β-catenin levels compared to healthy pituitary tissues. The high level of β-catenin in the invasive functional and non-functional tumors is indicative of the association of β-catenin with PitNETs invasion. The expression pattern of the β-catenin gene and protein was consistently and significantly associated with these tumor types. The correlation between β-catenin and insulin-like growth factor 1 (IGF-1) in GH-PitNETs indicates the potential relevance of β-catenin and IGF-1 for GH-PitNETs.

CONCLUSIONS

The simultaneous increase in the expression of β-catenin gene and protein level in PitNET tissues and their relationship to the tumor severity indicates the possible contributing role of β-catenin and its underlying signaling mediators in PitNET pathogenesis.

Tumor-associated macrophages promote epithelial-mesenchymal transition and the cancer stem cell properties in triple-negative breast cancer through CCL2/AKT/β-catenin signaling

BACKGROUND

Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer with poor prognosis and limited treatment. As a major component of the tumor microenvironment, tumor-associated macrophages (TAMs) play an important role in facilitating the aggressive behavior of TNBC. This study aimed to explore the novel mechanism of TAMs in the regulation of epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties in TNBC.

METHODS

Expression of the M2-like macrophage marker CD163 was evaluated by immunohistochemistry in human breast cancer tissues. The phenotype of M2 macrophages polarized from Tohoku-Hospital-Pediatrics-1 (THP1) cells was verified by flow cytometry. Transwell assays, wound healing assays, western blotting, flow cytometry, ELISA, quantitative polymerase chain reaction (qPCR), luciferase reporter gene assays, and immunofluorescence assays were conducted to investigate the mechanism by which TAMs regulate EMT and CSC properties in BT549 and HCC1937 cells.

RESULTS

Clinically, we observed a high infiltration of M2-like tumor-associated macrophages in TNBC tissues and confirmed that TAMs were associated with unfavorable prognosis in TNBC patients. Moreover, we found that conditioned medium from M2 macrophages (M2-CM) markedly promoted EMT and CSC properties in BT549 and HCC1937 cells. Mechanistically, we demonstrated that chemokine (C-C motif) ligand 2 (CCL2) secretion by TAMs activated Akt signaling, which in turn increased the expression and nuclear localization of β-catenin. Furthermore, β-catenin knockdown reversed TAM-induced EMT and CSC properties.

CONCLUSIONS

This study provides a novel mechanism by which TAMs promote EMT and enhance CSC properties in TNBC via activation of CCL2/AKT/β-catenin signaling, which may offer new strategies for the diagnosis and treatment of TNBC. Video Abstract.

Upregulation of the transmembrane protease serine 3 mRNA level in radioresistant colorectal cancer tissues

Aim: To investigate the clinical role of transmembrane protease serine 3 (TMPRSS3) in radioresistance and prognosis of colorectal cancer (CRC). Methods: Standardized mean difference (SMD) and summary area under the curve (AUC) of TMPRSS3 were calculated by combining all available high-throughput data globally. The prognostic significance of TMPRSS3 was determined by Kaplan-Meier and Cox regression analyses. Results: TMPRSS3 was remarkably upregulated in 198 CRC radioresistant cases compared with nonradioresistance (SMD = 0.38, AUC = 0.71). Overexpression of TMPRSS3 was observed in 1601 CRC patients compared with control subjects without CRC. TMPRSS3 was a risk factor for disease-free survival of CRC with the summarized hazard ratio 1.28. Conclusion: TMPRSS3 contributes to the radioresistance and unfavorable prognosis of CRC.

Quercetin Impairs HuR-Driven Progression and Migration of Triple Negative Breast Cancer (TNBC) Cells

In the present study, we have explored the prognostic value of HuR gene as well as protein in breast cancers. Furthermore, we have also investigated the HuR therapeutic relevance in TNBCs, which is an aggressive breast cancer subtype. Using an online meta-analysis tool, we found that HuR protein overexpression positively correlates with reduced overall survival of TNBC patients (p = 0.028). Furthermore, we demonstrated that the TNBC breast cancer cell lines i.e., MDA-MB-231 and MDA-MB-468 are good model systems to study HuR protein, as they both exhibit a significant amount of cytoplasmic HuR (active form). Quercetin treatment significantly inhibited the cytoplasmic HuR in both TNBC cell lines. By using specific HuR siRNA, we established that quercetin-mediated inhibition of adhesion and migration of TNBC cells is dependent on HuR. Upon analyzing adhesion proteins i.e., β-catenin and CD44, we found that quercetin mediated effect on TNBC adhesion and migration was through the HuR-β-catenin axis and CD44, independently. Overall, the present results demonstrate that elevated HuR levels are associated with TNBC progression and relapse, and the ability of quercetin to inhibit cytoplasmic HuR protein provides a rationale for using it as an anticancer agent for the treatment of aggressive TNBCs.Supplemental data for this article is available online at at 10.1080/01635581.2021.1952628.

Inhibiting β-catenin disables nucleolar functions in triple-negative breast cancer

Triple-negative breast cancer (TNBC) patients with upregulated Wnt/β-catenin signaling often have poor clinical prognoses. During pathological examinations of breast cancer sections stained for β-catenin, we made the serendipitous observation that relative to non-TNBC, specimens from TNBC patients have a greater abundance of nucleoli. There was a remarkable direct relationship between nuclear β-catenin and greater numbers of nucleoli in TNBC tissues. These surprising observations spurred our investigations to decipher the differential functional relevance of the nucleolus in TNBC versus non-TNBC cells. Comparative nucleolar proteomics revealed that the majority of the nucleolar proteins in TNBC cells were potential targets of β-catenin signaling. Next, we undertook an analysis of the nucleolar proteome in TNBC cells in response to β-catenin inhibition. This effort revealed that a vital component of pre-rRNA processing, LAS1 like ribosome biogenesis factor (LAS1L) was significantly decreased in the nucleoli of β-catenin inhibited TNBC cells. Here we demonstrate that LAS1L protein expression is significantly elevated in TNBC patients, and it functionally is important for mammary tumor growth in xenograft models and enables invasive attributes. Our observations highlight a novel function for β-catenin in orchestrating nucleolar activity in TNBCs.

Regulation of valproic acid induced EMT by AKT/GSK3β/β-catenin signaling pathway in triple negative breast cancer

Valproic acid (VPA) is a selective histone deacetylation (HDAC) inhibitor and exerts anti-cancer properties in different types of cancer. The epithelial-to-mesenchymal transition (EMT) mediating by different signaling cascade can be a potential target in aggressive human cancers. Therefore, we aimed to clarified the unravel relationship between AKT/GSK3β/β-catenin signalling pathway and VPA-induced EMT in triple negative breast cancer (TNBC). The cytotoxicity of VPA in MDA-MB-231 TNBC and MCF-10A control cells was evaluated. Alterations in the expression levels of Snail, E-cadherin, AKT, GSK3β, β-catenin were analyzed by RT-PCR. Additionally, Annexin V, cell cycle and wound healing assays were performed. Our results showed that VPA remarkably inhibited the growth of TNBC cell and triggered apoptotic cell death through G0/G1 arrest. Furthermore, VPA increased cell migration and activated the EMT process through significantly increasing Snail expression and in turn downregulation of E-cadherin and GKS3β levels. However, the level of AKT and β-catenin was reduced after treatment of VPA. Our data showed that VPA induced EMT process and cell migration in TNBC cells. However, AKT/GSK3β/β-catenin signaling pathway did not mediate EMT activation.

Development and validation of a prognostic nomogram for patients with triple-negative breast cancer with histology of infiltrating duct carcinoma

Background

The purpose of this study was to develop prognostic nomograms from a cohort of patients with triple-negative breast cancer (TNBC) with histology of infiltrating duct carcinoma (IDC) by correlating their clinical and pathological parameters with the rates of disease-free survival (DFS) and overall survival (OS).

Methods

We retrospectively analyzed TNBC patients with histology of IDC at our institution between 2009 and 2012. Age, family history, menopausal status, surgery type, T stage, N stage, histological grade, vascular invasion, perineural invasion, cytokeratin 5/6 status, Ki-67 expression, and epithelial cadherin (E-cadherin) status were analyzed. Predictors were used in multivariable logistic regression analysis to develop a nomogram to predict DFS and OS rates. The nomograms were then subjected to internal validation, with external validation of the nomogram for predicting OS using separate cohorts of TNBC patients known from the Cancer Genome Atlas (TCGA) database. Using the concordance index (C-index) with calibration curves, the predictive accuracy and discriminative ability were calculated.

Results

A total of 242 eligible TNBC patients were included for analysis. The median follow-up time was 70.73 months. Of the patients, 32.6%, 42.6%, and 24.8% had stage I, II, and III disease, respectively. The 3- and 5-year survival rates were 81.0% and 76.5% for DFS, and 86.5% and 81.1%, for OS, respectively. Age, T stage, N stage, and E-cadherin status were found to be risk factors. The nomograms based on those risk factors accurately predicted the 3- and 5-year survival rates. The C-index was 0.798 and 0.821 for DFS and OS, respectively. Besides, the nomogram for OS showed relatively reliable performance in stratifying different risk groups of patients in training and validation cohorts identified from the TCGA database. The C-index reached 0.843. DFS validation was not completed, as there was insufficient data.

Conclusions

Using clinicopathological information, we produced a prognostic nomogram that accurately predicts the 3- and 5-year DFS and OS for patients with TNBC with histology of IDC. More external confirmation is required.

Anti-tumor peptide SA12 inhibits metastasis of MDA-MB-231 and MCF-7 breast cancer cells via increasing expression of the tumor metastasis suppressor genes, CDH1, nm23-H1 and BRMS1

In recent years, there has been progress in the treatment of breast cancer; however, the prognosis is still poor due to recurrence and metastasis following conventional treatment. The anti-tumor peptide SA12 has been demonstrated to inhibit proliferation and arrest the cell cycle in MDA-MB-231 and MCF-7 breast cancer cells. In the present study, whether SA12 was able to inhibit the metastasis of breast cancer cells was investigated. Wound healing and Transwell assays were used to investigate the inhibition of SA12 on cell migration while, reverse transcription-quantitative PCR and western blot assays were used to identify the mechanism of action behind the effects of SA12 on cell migration. Results from the wound healing and Transwell assays revealed that SA12 significantly inhibited the migration of MDA-MB-231 and MCF-7 breast cancer cells following treatment with 100 µM SA12. Compared with that in the controls, the mRNA expression levels of cadherin 1 (CDH1), non-metastasis 23-H1 (nm23-H1) and breast cancer metastasis suppressor 1 (BRMS1) were increased in MDA-MB-231 and MCF-7 cells following treatment with 100 µM SA12. Furthermore, the protein expression levels of E-cadherin, NM23A and BRMS1 were also increased in MDA-MB-231 cells and MCF-7 cells following treatment with 100 µM SA12. In conclusion, SA12 inhibited the migration of MDA-MB-231 and MCF-7 breast cancer cells and enhanced the expression of the tumor metastasis suppressor genes, CDH1, nm23-H1 and BRMS1, which may be responsible for the SA12-induced inhibition of breast cancer cell metastasis.

Vitamin D in Triple-Negative and BRCA1-Deficient Breast Cancer-Implications for Pathogenesis and Therapy

Several studies show that triple-negative breast cancer (TNBC) patients have the lowest vitamin D concentration among all breast cancer types, suggesting that this vitamin may induce a protective effect against TNBC. This effect of the active metabolite of vitamin D, 1α,25-dihydroxyvitamin D3 (1,25(OH)2D), can be attributed to its potential to modulate proliferation, differentiation, apoptosis, inflammation, angiogenesis, invasion and metastasis and is supported by many in vitro and animal studies, but its exact mechanism is poorly known. In a fraction of TNBCs that harbor mutations that cause the loss of function of the DNA repair-associated breast cancer type 1 susceptibility (BRCA1) gene, 1,25(OH)2D may induce protective effects by activating its receptor and inactivating cathepsin L-mediated degradation of tumor protein P53 binding protein 1 (TP53BP1), preventing deficiency in DNA double-strand break repair and contributing to genome stability. Similar effects can be induced by the interaction of 1,25(OH)2D with proteins of the growth arrest and DNA damage-inducible 45 (GADD45) family. Further studies on TNBC cell lines with exact molecular characteristics and clinical trials with well-defined cases are needed to determine the mechanism of action of vitamin D in TNBC to assess its preventive and therapeutic potential.

Fascin Activates β-Catenin Signaling and Promotes Breast Cancer Stem Cell Function Mainly Through Focal Adhesion Kinase (FAK): Relation With Disease Progression

Cancer stem cells (CSCs), a rare population of tumor cells with high self-renewability potential, have gained increasing attention due to their contribution to chemoresistance and metastasis. We have previously demonstrated a critical role for the actin-bundling protein (fascin) in mediating breast cancer chemoresistance through activation of focal adhesion kinase (FAK). The latter is known to trigger the β-catenin signaling pathway. Whether fascin activation of FAK would ultimately trigger β-catenin signaling pathway has not been elucidated. Here, we assessed the effect of fascin manipulation in breast cancer cells on triggering β-catenin downstream targets and its dependence on FAK. Gain and loss of fascin expression showed its direct effect on the constitutive expression of β-catenin downstream targets and enhancement of self-renewability. In addition, fascin was essential for glycogen synthase kinase 3β inhibitor-mediated inducible expression and function of the β-catenin downstream targets. Importantly, fascin-mediated constitutive and inducible expression of β-catenin downstream targets, as well as its subsequent effect on CSC function, was at least partially FAK dependent. To assess the clinical relevance of the in vitro findings, we evaluated the consequence of fascin, FAK, and β-catenin downstream target coexpression on the outcome of breast cancer patient survival. Patients with coexpression of fascin^high and FAK^high or high β-catenin downstream targets showed the worst survival outcome, whereas in fascin^low, patient coexpression of FAK^high or high β-catenin targets had less significant effect on the survival. Altogether, our data demonstrated the critical role of fascin-mediated β-catenin activation and its dependence on intact FAK signaling to promote breast CSC function. These findings suggest that targeting of fascin-FAK-β-catenin axis may provide a novel therapeutic approach for eradication of breast cancer from the root.

Evaluation of the Effect of Foeniculum vulgare on the Expression of E-Cadherin, Dysadherin and Ki-67 in BALB/C Mice with 4T1 Model of Breast Cancer

Introduction: Breast cancer is described as a serious disease and one of the important factors of cancer-related deaths. Considering the drug resistance, special attention has been paid to natural compounds. This study aimed at evaluating the anti-metastatic activity of fennel in a breast cancer mouse model.Methods: A total of 28 adult female BALB/C mice were used in this study. Breast cancer was induced by subcutaneous injection of 4T1 cells in the right lower flank. The mice received fennel extracts daily via intraperitoneal injection for two weeks. Meanwhile, tumor volume was measured every day using calipers. After two weeks, each animal was anesthetized. The expression levels of ki-67 and dysadherin as tumor markers, as well as E-cadherin as a tumor suppressor, were measured in tumor tissue and ovary. Also the expression of her2 was measured in ovary.Results: Tumor size significantly decreased after nine days treatment of the fennel. Fennel treatment caused an increase in the ratio of the expression of E-cadherin to Ki-67 and dysadherin in the tumor tissues. On the other hand, the expression of Ki-67 and HER2 decreased in the ovary.Conclusion: Based on our findings, fennel has anti-tumor and anti-metastatic activities against aggressive cancers.

Schlafen12 Reduces the Aggressiveness of Triple Negative Breast Cancer through Post-Transcriptional Regulation of ZEB1 That Drives Stem Cell Differentiation

BACKGROUND/AIMS

Schlafen12 (SLFN12) promotes human intestinal and prostatic epithelial differentiation. We sought to determine whether SLFN12 reduces triple-negative breast cancer (TNBC) aggressiveness.

METHODS

We validated bioinformatics analyses of publicly available databases by staining human TNBC. After virally overexpressing or siRNA-reducing SLFN12 in TNBC cell lines, we measured proliferation by CCK-8 assay, invasion into basement-membrane-coated pores, mRNA by q-RT-PCR and protein by Western blotting. Flow cytometry assessed proliferation and stem cell marker expression, and sorted CD44+/CD24- cells. Stemness was also assessed by mammosphere formation, and translation by click-it-AHA chemistry.

RESULTS

SLFN12 expression was lower in TNBC tumors and correlated with survival. SLFN12 overexpression reduced TNBC MDA-MB-231, BT549, and Hs578T proliferation. In MDA-MB-231 cells, AdSLFN12 reduced invasion, promoted cell cycle arrest, increased E-cadherin promoter activity, mRNA, and protein, and reduced vimentin expression and protein. SLFN12 knockdown increased vimentin. AdSLFN12 reduced the proportion of MDA-MB-231 CD44⁺CD24^- cells, with parallel differentiation changes. SLFN12 overexpression reduced MDA-MB-231 mammosphere formation. SLFN12 overexpression decreased ZEB1 and Slug protein despite increased ZEB1 and Slug mRNA in all three lines. SLFN12 overexpression accelerated MDA-MB-231 ZEB1 proteasomal degradation and slowed ZEB1 translation. SLFN12 knockdown increased ZEB1 protein. Coexpressing ZEB1 attenuated the SLFN12 effect on E-cadherin mRNA and proliferation in all three lines.

CONCLUSION

SLFN12 may reduce TNBC aggressiveness and improve survival in part by a post-transcriptional decrease in ZEB1 that promotes TNBC cancer stem cell differentiation.

IMP3 Stabilization of WNT5B mRNA Facilitates TAZ Activation in Breast Cancer

Insulin-like growth factor-2 mRNA-binding protein 3 (IMP3) is an oncofetal protein associated with many aggressive cancers and implicated in the function of breast cancer stem cells (CSCs). The mechanisms involved, however, are poorly understood. We observed that IMP3 facilitates the activation of TAZ, a transcriptional co-activator of Hippo signaling that is necessary for the function of breast CSCs. The mechanism by which IMP3 activates TAZ involves both mRNA stability and transcriptional regulation. IMP3 stabilizes the mRNA of an alternative WNT ligand (WNT5B) indirectly by repressing miR145-5p, which targets WNT5B, resulting in TAZ activation by alternative WNT signaling. IMP3 also facilitates the transcription of SLUG, which is necessary for TAZ nuclear localization and activation, by a mechanism that is also mediated by WNT5B. These results demonstrate that TAZ can be regulated by an mRNA-binding protein and that this regulation involves the integration of Hippo and alternative WNT-signaling pathways.

TUFT1 promotes metastasis and chemoresistance in triple negative breast cancer through the TUFT1/Rab5/Rac1 pathway

Background

Triple negative breast cancer (TNBC) is a breast cancer (BC) subtype that is characterized by its strong invasion and a high risk of metastasis. However, the specific mechanisms underlying these phenotypes are unclear. TUFT1 plays an important role in BC and impacts the proliferation and survival of BC cells. Recent studies have shown that TUFT1 mediates intracellular lysosome localization and vesicle transport by regulating Rab GTPase, but the relevance of this activity in TNBC is unknown. Therefore, our aim was to systematically study the role of TUFT1 in the metastasis and chemoresistance of TNBC.

Methods

We measured TUFT1, Rab5-GTP, and Rac1-GTP expression levels in samples of human TNBC by immunohistochemistry (IHC) and conducted univariate and multivariate analyses. shRNA-mediated knockdown and overexpression, combined with transwell assays, co-immunoprecipitation, a nude mouse xenograft tumor model, and GTP activity assays were used for further mechanistic studies.

Results

TUFT1 expression was positively correlated with Rab5-GTP and Rac1-GTP in the TNBC samples, and co-expression of TUFT1 and Rab5-GTP predicted poor prognosis in TNBC patients who were treated with chemotherapy. Mechanism studies showed that TUFT1 could activate Rab5 by binding to p85α, leading to activation of Rac1 through recruitment of Tiam1, and concurrent down-regulation of the NF-κB pathway and proapoptotic factors, ultimately promoting metastasis and chemoresistance in TNBC cells.

Conclusions

Our findings suggest that the TUFT1/Rab5/Rac1 pathway may be a potential target for the effective treatment of TNBC.

First-in-Class Phosphorylated-p68 Inhibitor RX-5902 Inhibits β-Catenin Signaling and Demonstrates Antitumor Activity in Triple-Negative Breast Cancer

RX-5902 is a first-in-class anticancer agent targeting phosphorylated-p68 and attenuating nuclear shuttling of β-catenin. The purpose of this study was to evaluate the efficacy of RX-5902 in preclinical models of triple-negative breast cancer (TNBC) and to explore effects on β-catenin expression. A panel of 18 TNBC cell lines was exposed to RX-5902, and changes in proliferation, apoptosis, cellular ploidy, and effector protein expression were assessed. Gene expression profiling was used in sensitive and resistant cell lines with pathway analysis to explore pathways associated with sensitivity to RX-5902. The activity of RX-5902 was confirmed in vivo in cell line and patient-derived tumor xenograft (PDX) models. RX-5902 demonstrated potent antiproliferative activity in vitro against TNBC cell lines with an average IC₅₀ of 56 nmol/L in sensitive cell lines. RX-5902 treatment resulted in the induction of apoptosis, G₂-M cell-cycle arrest, and aneuploidy in a subset of cell lines. RX-5902 was active in vivo against TNBC PDX models, and treatment resulted in a decrease in nuclear β-catenin. RX-5902 exhibited dose-proportional pharmacokinetics and plasma and tumor tissue in nude mice. Pathway analysis demonstrated an increase in the epithelial-to-mesenchymal transformation (EMT), TGFβ, and Wnt/β-catenin pathways associated with sensitivity to RX-5902. RX-5902 is active against in vitro and in vivo preclinical models of TNBC. Target engagement was confirmed with decreases in nuclear β-catenin and MCL-1 observed, confirming the proposed mechanism of action. This study supports the continued investigation of RX-5902 in TNBC and combinations with immunotherapy.

IL-6 Impairs the Activity of Vitamin D3 in the Regulation of Epithelial-Mesenchymal Transition in Triple Negative Breast Cancer

Objective:

The present study aimed to investigate the possible role of IL-6 and 1α,25-dihydroxyvitamin D3 (1,25D) signaling in epithelial-mesenchymal transition (EMT) and stemness in triple-negative breast cancer (TNBC) cell line.

Methods:

TNBC cell line, HCC 1806, was treated with IL-6 and 1,25D for three and six days. Also, the role of vitamin D receptor (VDR) was studied by transfection of TNBC cell line with VDR gene and transfection efficiency was assessed using Human VDR enzyme-linked immunosorbent assay (ELISA). Changes in E-cadherin gene expression were analyzed by quantitative real-time PCR (qRT-PCR). Also, changes in CD44+ cells were analyzed by flow cytometry. Finally, morphological changes were investigated by light microscopy after 6 days.

Results:

Treatment of HCC1806 cells with IL-6 has no significant effect either on E-cadherin gene expression or CD44+ cells, (p > 0.05). However, E-cadherin gene expression was significantly up-regulated after treatment with 1,25D for 6 days, (p < 0.05). Also, CD44+ cells were significantly reduced after treatment with 1,25D either for 3 or 6 days, (p < 0.05). Transfection of TNBC cell line with VDR gene significantly up-regulated VDR protein expression, (p < 0.05). In addition, overexpression of VDR in TNBC cells and treatment with 1,25D significantly up-regulated E-cadherin gene expression, (p < 0.05) and reduced CD44+ cells, (p < 0.05). Moreover, transfection with VDR and treatment with a combination of 1,25D and IL-6 significantly down-regulated E-cadherin gene expression and increased CD44+ cells compared with transfected cells with VDR treated with 1,25D alone, (p < 0.05). No significant morphological changes were observed in treated cells, 6 days post-treatment.

Conclusion:

The presence of IL-6 in the breast tumor microenvironment may impair the activity of vitamin D3 signaling, limiting its anti-tumor effects in TNBC.

TUFT1 Promotes Triple Negative Breast Cancer Metastasis, Stemness, and Chemoresistance by Up-Regulating the Rac1/β-Catenin Pathway

Objectives: Triple negative breast cancer (TNBC) is a subtype of breast cancer with stronger invasion and metastasis, but its specific mechanism of action is still unclear. Tuft1 plays an important regulatory role in the survival of breast cancer cells; however, its role in regulating TNBC metastatic potential has not been well-characterized. Our aim was therefore to systematically study the mechanism of TUFT1 in the metastasis, stemness, and chemoresistance of TNBC and provide new predictors and targets for BC treatment. Methods: We used western blotting and IHC to measure TUFT1and Rac1-GTP expression levels in both human BC samples and cell lines. A combination of shRNA, migration/invasion assays, sphere formation assay, apoptosis assays, nude mouse xenograft tumor model, and GTP activity assays was used for further mechanistic studies. Results: We demonstrated that silencing TUFT1 in TNBC cells significantly inhibited cell metastasis and stemness in vitro. A nude mouse xenograft tumor model revealed that TUFT1 knockdown greatly decreased spontaneous lung metastasis of TNBC tumors. Mechanism studies showed that TUFT1 promoted tumor cell metastasis and stemness by up-regulating the Rac1/β-catenin pathway. Moreover, mechanistic studies indicated that the lack of TUFT1 expression in TNBC cells conferred more sensitive to chemotherapy and increased cell apoptosis via down-regulating the Rac1/β-catenin signaling pathway. Further, TUFT1 expression positively correlated with Rac1-GTP in TNBC samples, and co-expression of TUFT1 and Rac1-GTP predicted poor prognosis in TNBC patients who treated with chemotherapy. Conclusion: Our findings suggest that TUFT1/Rac1/β-catenin pathway may provide a potential target for more effective treatment of TNBC.

PDLIM2 Is a Marker of Adhesion and β-Catenin Activity in Triple-Negative Breast Cancer

The PDLIM2 protein regulates stability of transcription factors including NF-κB and STATs in epithelial and hemopoietic cells. PDLIM2 is strongly expressed in certain cancer cell lines that exhibit an epithelial-to-mesenchymal phenotype, and its suppression is sufficient to reverse this phenotype. PDLIM2 supports the epithelial polarity of nontransformed breast cells, suggesting distinct roles in tumor suppression and oncogenesis. To better understand its overall function, we investigated PDLIM2 expression and activity in breast cancer. PDLIM2 protein was present in 60% of tumors diagnosed as triple-negative breast cancer (TNBC), and only 20% of other breast cancer subtypes. High PDLIM2 expression in TNBC was positively correlated with adhesion signaling and β-catenin activity. Interestingly, PDLIM2 was restricted to the cytoplasm/membrane of TNBC cells and excluded from the nucleus. In breast cell lines, PDLIM2 retention in the cytoplasm was controlled by cell adhesion, and translocation to the nucleus was stimulated by insulin-like growth factor-1 or TGFβ. Cytoplasmic PDLIM2 was associated with active β-catenin and ectopic expression of PDLIM2 was sufficient to increase β-catenin levels and its transcriptional activity in reporter assays. Suppression of PDLIM2 inhibited tumor growth in vivo, whereas overexpression of PDLIM2 disrupted growth in 3D cultures. These results suggest that PDLIM2 may serve as a predictive biomarker for a large subset of TNBC whose phenotype depends on adhesion-regulated β-catenin activity and which may be amenable to therapies that target these pathways. SIGNIFICANCE: This study shows that PDLIM2 expression defines a subset of triple-negative breast cancer that may benefit from targeting the β-catenin and adhesion signaling pathways. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/79/10/2619/F1.large.jpg.

MiR-125b regulates the proliferation and metastasis of triple negative breast cancer cells via the Wnt/β-catenin pathway and EMT

BACKGROUND/AIM

MiR-125b plays an important role in breast cancer. The current study was to explore the expression and function of miR-125b in triple negative breast cancer cells.

MATERIALS AND METHODS

The expression of miR-125b in human TNBC samples and cell lines were examined by qRT-PCR. MTT, scratch assays and transwell assays were utilized to observe the proliferation, migration and invasion ability. MiR-125b's target gene and downstream signaling pathways were investigated by Luciferase Reporter Assays, qRT-PCR, immunofluorescence assays and western bolt.

RESULTS

MiR-125b was highly expressed in human TNBC tissues and cell lines. Inhibiting miR-125b expression suppressed the proliferation, cell migration and invasion. The three-prime untranslated region (3´-UTR) of adenomatous polyposis coli (APC) mRNA contains miR-125b binding sites, and inhibiting miR-125b expression suppressed the activity of the intracellular Wnt/β-catenin pathways and EMT.

CONCLUSION

Inhibiting miR-125b regulates the Wnt/β-catenin pathway and EMT to suppress the proliferation and migration of MDA-MB-468 TNBC cells.

Targeting triple negative breast cancer heterogeneity with chalcones: a molecular insight

Triple negative breast cancers (TNBCs) are aggressive heterogeneous cancers with not yet determined conventional targeted medication. Therefore, identification of new alternatives or improved treatment options to combat this deadly disease is highly needed. On the other hand, various derived products with chalcone scaffold were historically considered excellent candidates for the development of anticancer drugs. Chalcones unique chemical structure and their substantial biological activities in cancer cells make them an extremely attractive target for the treatment of several human carcinomas including TNBCs. This review highlights the promising therapeutic role of chalcones in TNBC management.

Dickkopf-1 (Dkk1) protein expression in breast cancer with special reference to bone metastases

Dysregulation of the Wnt inhibitor dickkopf-1 protein (Dkk1) has been reported in a variety of cancers. In addition, it has been linked to the progression of malignant bone disease by impairing osteoblast activity. This study investigated serum- and tissue levels of Dkk1 in breast cancer patients with- or without bone metastases. Serum Dkk1 levels were measured by ELISA in 89 breast cancer patients and 86 healthy women. Tissue levels of Dkk1 and β-catenin, a major downstream component of Wnt transduction pathway, were tested with immunohistochemical staining in 143 different tissues, including adjacent non-tumoral breast tissues, primary breast tumours, lymph nodes metastases, and bone metastases. Serum levels of Dkk1 were significantly increased in breast cancer patients without metastases compared with healthy controls and even more increased in patients with bone metastases. Tissue expression of Dkk1 was positive in 70% of tested primary breast cancer tissues and demonstrated significant correlation with histological type and PR status. Less frequent expression of Dkk1 was found in lymph nodes metastases and bone metastases compared with adjacent non-tumoral breast tissues and primary breast tumours. Tissue expression of β-catenin was positive in the vast majority of all tested tissue types indicating activated Wnt/β-catenin signalling. Our results suggested that Wnt/β-catenin signalling in breast tumours and their secondary lymph nodes- and bone metastases is dysregulated and this could be related to aberrant Dkk1 expression levels. Hence, Dkk1 protein might provide insights into the continued development of novel comprehensive and therapeutic strategies for breast cancer and its bone metastases.

Antitumoral and antimetastatic activity of Maitake D-Fraction in triple-negative breast cancer cells

Triple-negative breast cancer (TNBC) is associated with poor prognosis, high local recurrence rate and high rate of metastasis compared with other breast cancer subtypes. In addition, TNBC lacks a targeted therapy. This scenario highlights the need for novel compounds with high potential for TNBC treatment. In this regard, natural products are important sources of anticancer drugs. D-Fraction, a proteoglucan extracted from the edible and medicinal mushroom Grifola frondosa (Maitake), is a dietary supplement that has been shown to exert both immunostimulatory and immune-independent antitumoral effects on some cancer types. However, its antitumoral potential in TNBC is unknown. Therefore, we employed TNBC cells to investigate if D-Fraction is able to attenuate their aggressive phenotype. We found that D-Fraction decreases MDA-MB-231 cell viability through apoptosis induction and reduces their metastatic potential. D-Fraction increases cell-cell adhesion by increasing E-cadherin protein levels and β-catenin membrane localization, and increases cell-substrate adhesion. D-Fraction also decreases cell motility by affecting actin cytoskeleton rearrangements, and proteolytic activity of MMP-2 and MMP-9. Furthermore, D-Fraction decreases the invasive capacity of MDA-MB-231 cells. In concordance, D-Fraction retards tumor growth and reduces lung metastases in a xenograft model. Altogether, these results suggest the potential therapeutic role of D-Fraction in aggressive TNBC.

E-Cadherin/ROS1 Inhibitor Synthetic Lethality in Breast Cancer

The cell adhesion glycoprotein E-cadherin (CDH1) is commonly inactivated in breast tumors. Precision medicine approaches that exploit this characteristic are not available. Using perturbation screens in breast tumor cells with CRISPR/Cas9-engineered CDH1 mutations, we identified synthetic lethality between E-cadherin deficiency and inhibition of the tyrosine kinase ROS1. Data from large-scale genetic screens in molecularly diverse breast tumor cell lines established that the E-cadherin/ROS1 synthetic lethality was not only robust in the face of considerable molecular heterogeneity but was also elicited with clinical ROS1 inhibitors, including foretinib and crizotinib. ROS1 inhibitors induced mitotic abnormalities and multinucleation in E-cadherin-defective cells, phenotypes associated with a defect in cytokinesis and aberrant p120 catenin phosphorylation and localization. In vivo, ROS1 inhibitors produced profound antitumor effects in multiple models of E-cadherin-defective breast cancer. These data therefore provide the preclinical rationale for assessing ROS1 inhibitors, such as the licensed drug crizotinib, in appropriately stratified patients.Significance: E-cadherin defects are common in breast cancer but are currently not targeted with a precision medicine approach. Our preclinical data indicate that licensed ROS1 inhibitors, including crizotinib, should be repurposed to target E-cadherin-defective breast cancers, thus providing the rationale for the assessment of these agents in molecularly stratified phase II clinical trials. Cancer Discov; 8(4); 498-515. ©2018 AACR.This article is highlighted in the In This Issue feature, p. 371.

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.

The prognostic significance of combined androgen receptor, E-Cadherin, Ki67 and CK5/6 expression in patients with triple negative breast cancer

Background

Triple Negative Breast Cancer (TNBC) represents a heterogeneous group of tumors with poor prognosis owing to aggressive tumor biology and lack of targeted therapies. No clear prognostic biomarkers have been identified to date for this subgroup.

Materials and Methods

In this retrospective study we evaluated the prognostic role of 4 different molecular determinants, including androgen receptor (AR), E-cadherin (CDH1), Ki67 index, and basal cytokeratins (CKs) 5/6, in a cohort of 99 patients with TNBC. All patients received neo/adjuvant chemotherapy (mostly anthracycline/taxane-based). Immunohistochemistry (IHC) was performed in formalin-fixed paraffin-embedded primary tumor samples. CDH1 expression was considered positive as ≥ 30% of the membrane cells staining. AR positivity was defined as > 10% of positive tumor cells. High Ki67 was defined as ≥20% positive tumor cells. CK5/6 expression was judged positive if the score was ≥1.

Results

The absence of AR expression was significantly associated with highly undifferentiated tumors. Univariate analyses showed that lack of expression of CDH1, tumor size and nodal status were significantly correlated with worse RFS and OS (p< 0.05). AR expression and low Ki67 showed a trend towards better RFS and OS. Patients with absent CK5/6 expression in univariate and multivariate analyses had poorer RFS (p=0.02 and p=0.002, respectively) and OS (p=0.05 and p=0.02, respectively). Multivariate analysis showed an independent association between CDH1 expression and better RFS and OS (p< 0.05) beyond tumor size, nodal status, and grade. The Kaplan-Meier curves showed that patients with AR and CDH1 negative expression and high Ki-67 levels have a significant correlation with poor outcome.

Conclusions

Our study supports the use of IHC expression of AR, CDH1, Ki67, and CK5/6 as prognostic markers in TNBCs and suggests a link between their expression and prognosis and may help to stratify TNBC patients in different prognostic classes.

Ormeloxifene Suppresses Prostate Tumor Growth and Metastatic Phenotypes via Inhibition of Oncogenic β-catenin Signaling and EMT Progression

Ormeloxifene is a clinically approved selective estrogen receptor modulator, which has also shown excellent anticancer activity, thus it can be an ideal repurposing pharmacophore. Herein, we report therapeutic effects of ormeloxifene on prostate cancer and elucidate a novel molecular mechanism of its anticancer activity. Ormeloxifene treatment inhibited epithelial-to-mesenchymal transition (EMT) process as evident by repression of N-cadherin, Slug, Snail, vimentin, MMPs (MMP2 and MMP3), β-catenin/TCF-4 transcriptional activity, and induced the expression of pGSK3β. In molecular docking analysis, ormeloxifene showed proficient docking with β-catenin and GSK3β. In addition, ormeloxifene induced apoptosis, inhibited growth and metastatic potential of prostate cancer cells and arrested cell cycle in G₀-G₁ phase via modulation of cell-cycle regulatory proteins (inhibition of Mcl-1, cyclin D1, and CDK4 and induction of p21 and p27). In functional assays, ormeloxifene remarkably reduced tumorigenic, migratory, and invasive potential of prostate cancer cells. In addition, ormeloxifene treatment significantly (P < 0.01) regressed the prostate tumor growth in the xenograft mouse model while administered through intraperitoneal route (250 μg/mouse, three times a week). These molecular effects of ormeloxifene were also observed in excised tumor tissues as shown by immunohistochemistry analysis. Our results, for the first time, demonstrate repurposing potential of ormeloxifene as an anticancer drug for the treatment of advanced stage metastatic prostate cancer through a novel molecular mechanism involving β-catenin and EMT pathway. Mol Cancer Ther; 16(10); 2267-80. ©2017 AACR.

Wnt/beta-catenin pathway: modulating anticancer immune response

Wnt/β-catenin signaling, a highly conserved pathway through evolution, regulates key cellular functions including proliferation, differentiation, migration, genetic stability, apoptosis, and stem cell renewal. The Wnt pathway mediates biological processes by a canonical or noncanonical pathway, depending on the involvement of β-catenin in signal transduction. β-catenin is a core component of the cadherin protein complex, whose stabilization is essential for the activation of Wnt/β-catenin signaling. As multiple aberrations in this pathway occur in numerous cancers, WNT-directed therapy represents an area of significant developmental therapeutics focus. The recently described role of Wnt/β-catenin pathway in regulating immune cell infiltration of the tumor microenvironment renewed the interest, given its potential impact on responses to immunotherapy treatments. This article summarizes the role of Wnt/β-catenin pathway in cancer and ongoing therapeutic strategies involving this pathway.