Toremifene, an Alternative Adjuvant Endocrine Therapy, Is Better Than Tamoxifen in Breast Cancer Patients with CYP2D6*10 Mutant Genotypes.

PURPOSE: Tamoxifen showed individual differences in efficacy under different CYP2D6*10 genotypes. Our study evaluated the prognosis of tamoxifen or toremifene in hormone receptor (HR)-positive breast cancer patients under different genotypes. MATERIALS AND METHODS: CYP2D6*10 genotypes of HR-positive breast cancer patients were determined by Sanger sequencing, and all the patients were divided into tamoxifen group or toremifene group. RESULTS: A total of 268 patients with HR-positive breast cancer were studied. The median follow-up time was 72.0 months (range, 5.0 to 88.0 months). Of these, 88 (32.9%), 114 (42.5%), and 66 (24.6%) patients had C/C, C/T, and T/T genotypes, respectively. Among patients who received tamoxifen (n=176), the 5-year disease-free survival (DFS) rate in patients with C/C and C/T genotype was better than that in patients with T/T genotype, and the difference was statistically significant (p < 0.001 and p=0.030, respectively). In patients receiving toremifene, CYP2D6*10 genotype was not significantly associated with DFS (p=0.325). Regardless of genotypes, the 5-year DFS rate was higher in patients treated with toremifene than in patients with tamoxifen (91.3% vs. 80.0%, p=0.011). Compared with tamoxifen, toremifene remained an independent prognostic marker of DFS in multivariate analysis (hazard ratio, 0.422; p=0.021). For all the 180 patients with CYP2D6*10 C/T and T/T genotypes, the 5-year DFS rate was significantly higher in the toremifene group than in the tamoxifen group (90.8% vs. 70.1%, p=0.003). CONCLUSION: Toremifene may be an alternative adjuvant endocrine therapy for patients with CYP2D6*10 mutant genotypes.

LncRNA GATA3-AS1 facilitates tumour progression and immune escape in triple-negative breast cancer through destabilization of GATA3 but stabilization of PD-L1.

OBJECTIVES: Long non-coding RNAs (lncRNAs) have been demonstrated as crucial regulators in cancer, but whether they are involved in the immune response of cancer cells remains largely undiscovered. GATA3-AS1 is a novel lncRNA that was upregulated in breast cancer (BC) according to online databases. However, its role in triple-negative breast cancer (TNBC) was elusive. METHODS: GATA3-AS1 expression in BC tissues and adjacent normal tissues was obtained from online databases. Loss-of-function assays were designed and conducted to verify the functional role of GATA3-AS1 in TNBC cells. Bioinformatic analysis and mechanism experiments were applied to explore the downstream molecular mechanism of GATA3-AS1. Similarly, the upstream mechanism which led to the upregulation of GATA3-AS1 in TNBC cells was also investigated. RESULTS: GATA3-AS1 was markedly overexpressed in TNBC tissues and cells. Knockdown of GATA3-AS1 suppressed TNBC cell growth and enhanced the resistance of TNBC cells to immune response. GATA3-AS1 induced the deubiquitination of PD-L1 through miR-676-3p/COPS5 axis. GATA3-AS1 destabilized GATA3 protein by promoting GATA3 ubiquitination. CONCLUSION: GATA3-AS1 contributed to TNBC progression and immune evasion through stabilizing PD-L1 protein and degrading GATA3 protein, offering a new target for the treatment of TNBC.

Over-expression of CDX2 alleviates breast cancer by up-regulating microRNA let-7b and inhibiting COL11A1 expression.

BACKGROUND: microRNA Let-7 serves as a tumor suppressor by targeting various oncogenic pathways in cancer cells. However, the underlying mechanism of its involvement in breast cancer remains largely unknown. With our research, our endeavor is to explore the role of the CDX2/let-7b/COL11A1 axis in breast cancer cell activities. METHODS: Tumor tissues and adjacent normal tissues were collected from 86 patients with breast cancer. Human breast cancer epithelial cell line MCF-7 was treated with over-expressed CDX2, let-7b mimic, shRNA against COL11A1 and their negative controls. The expression of CDX2, let-7b, and COL11A1 in the tissues and cells was determined by RT-qPCR. Interactions among CDX2, let-7b, and COL11A1 were detected by ChIP and dual-luciferase reporter assay, respectively. After different transfections, cell invasion, migration, and proliferation abilities were determined by Transwell and EdU assays. Lastly, tumor xenografts in nude mice were established and hematoxylin and eosin staining was performed to assess the tumor growth and lymph node metastasis. RESULTS: CDX2 and let-7b were poorly expressed in breast cancer cells and tissues. CDX2 bound to let-7b and promoted the expression of let-7b, which contrarily inhibited the expression of COL11A1. Cancer cell proliferation, invasion, migration, and metastasis were stimulated when CDX2 and let-7b were depleted or COL11A1 was over-expressed. Xenograft tumors growth and metastasis were in accordance with the results of cellular experiments. CONCLUSION: In agreement with these observations, we could reach a conclusion that CDX2 could promote let-7b expression, which may exert an inhibitory effect on the proliferation, migration, and metastasis of breast cancer cells via repressing the expression of COL11A1, providing a novel therapeutic strategy for the treatment of metastatic breast cancer.

Over-expression of FSIP1 promotes breast cancer progression and confers resistance to docetaxel via MRP1 stabilization.

Fibrous sheath-interacting protein 1 (FSIP1) functions centrally in breast carcinogenesis and progression, although its exact role remains to be clarified. Therefore, we sought to establish a correlation between the clinico-pathological features of breast cancer and FSIP1 expression in breast cancer tissues, as well as to validate its role in tumor progression and chemo-resistance. We analyzed FSIP1 expression in the breast cancer and para-tumor tissues by immunohistochemistry. We performed MTT, Caspase-Glo 3/7 Assay, Annexin V staining, wound healing and trans-well assays to evaluate cellular apoptosis, proliferation, migration and invasion in FSIP1 knockout and wild-type breast cancer cell lines. Additionally, we examined the effects of FSIP1 on docetaxel sensitivity in a nude mice model transplanted with control or FSIP1 knockout breast cancer cells, and also evaluate its role in tumor metastasis. FSIP1 and MRP1 interaction was determined by co-immunoprecipitation and mass spectrometry. We found that breast cancer cells and tissues consistently demonstrated elevated FSIP1 expressions, which correlated with poor overall survival. Notably, patients with high FSIP1 expression in their tumors undergoing docetaxel neoadjuvant chemotherapy had shorter disease-free survival. FSIP1 knockout in breast cancer cells significantly increased their sensitivity to docetaxel both in vitro and in vivo. Mechanistically, FSIP1 bound to the multidrug resistance protein 1 (MRP1) and stabilized it, and knocking out FSIP1 decreased MRP1 expression and increased cellular docetaxel accumulation. In sum, FSIP1 promotes breast carcinogenesis and mediates docetaxel resistance, and may serve as a novel target in the development of breast cancer therapies.

MiR-23a promotes TGF-ß1-induced EMT and tumor metastasis in breast cancer cells by directly targeting CDH1 and activating Wnt/ß-catenin signaling.

TGF-ß1-induced epithelial-mesenchymal transition (EMT) has been proved to be associated with metastasis of breast cancer cells. We attempted to detect a novel mechanism that microRNAs mediated the TGF-ß1-induced EMT in the process of breast cancer metastasis. Here we reported that the expression of miR-23a was higher in breast cancer cells with high metastasis ability and patients with lymph node metastasis and the treatment of TGF-ß1 significantly upregulated the expression of miR-23a in breast cancer cells. We found that miR-23a was upregulated by TGF-ß1 post-transcriptionally and Smads directly bound the RNA Smad binding element (R-SBE) of miR-23a. Functional studies showed that inhibition of miR-23a suppressed the TGF-ß1-induced EMT, migration, invasion and metastasis of breast cancer both in vitro and in vivo. In addition, we determined that miR-23a directly targeted and suppressed CDH1, one important gene in EMT phenomenon. Notably, Wnt/ß-catenin signaling was activated by the suppression of CDH1 in the miR-23a mediated process of TGF-ß1-induced EMT and tumor invasion. These results demonstrate that miR-23a promotes TGF-ß1-induced tumor metastasis in breast cancer by targeting CDH1 and activating Wnt/ß-catenin signaling. Taken together, our results indicate a novel regulatory mechanism of TGF-ß1-induced EMT and suggest that miR-23a might be a potential target in breast cancer therapy.

HOXD13 methylation status is a prognostic indicator in breast cancer.

Homeobox protein Hox-D13 is encoded by HOXD13 gene which is frequently methylated in cancer and has been recognized as a tumor suppressor in pancreatic cancer. In this study, we examined HOXD13 mRNA expression in 40 pairs of breast cancers and corresponding normal breast tissues. Bisulfite sequencing of HOXD13 promoter was performed in 6 pairs of breast tumors and corresponding normal breast tissues to examine the potential HOXD13 CpG methylated sites. HOXD13 DNA methylation frequency analysis was performed using MethyLight in 196 pairs of breast cancers and corresponding normal breast samples. DNA methylation status and clinico-pathological features were investigated. Kaplan-Meier survival analysis and Cox proportional hazards models were utilized to assess the effect of methylation status on overall survival. We found that 60% (24/40) of breast cancers showed low HOXD13 mRNA expression when compared with corresponding normal breast tissue. The predicted CpG island was located in the -1325 bp to +675 bp region. Next, the -332 bp site in HOXD13 gene promoter was further examined and in 57.7% (113/196) samples methylation was detected at this site. HOXD13 methylation was correlated with larger tumor size (P = 0.004), but not with other clinico-pathological parameters. In addition, patients with methylated -HOXD13 promoter had worse overall survival (OS) (P = 0.005). Based on our results we conclude that HOXD13 methylation is a common event in primary breast cancer and is associated with poor survival of breast cancer patients. HOXD13 methylation could therefore potentially be used as a prognostic factor for breast cancer.

Association of FGFR3 and FGFR4 gene polymorphisms with breast cancer in Chinese women of Heilongjiang province.

BACKGROUND: The fibroblast growth factor (FGF) receptor pathway is activated in many tumors. FGFR2 has been identified as a breast cancer susceptibility gene. Common variation in other FGF receptors might also affect breast cancer risk. We carried out a case-control study to investigate associations of variants in FGFR3 and FGFR4 with breast cancer in women from Heilongjiang Province. METHODS: SNP rs2234909 and rs3135848 in FGFR3 and rs1966265 and rs351855 in FGFR4 were successfully genotyped in 747 breast cancer patients and 716 healthy controls using the SNaPshot method. The associations between SNPs and breast cancer were examined by logistic regression. The associations between SNPs and disease characteristics were examined by chi-square tests or one-way ANOVA as needed. RESULTS: The minor alleles of rs1966265 and rs351855 in FGFR4 were strongly associated with breast cancer in the population, with odds ratios of 1.335 (95%CI = 1.154-1.545) and 1.364 (95%CI = 1.177-1.580), respectively. However, no significant associations were detected between other SNPs and breast cancer. Analyses of the disease characteristics showed that SNP rs351855 was associated with lymph-node-positive breast cancer with a dose-dependent effect of the minor allele (P = 0.008). CONCLUSIONS: SNPs rs1966265 and rs351855 in FGFR4 were associated with breast cancer in a northern Chinese population.

Surgical treatment of gynecomastia: mastectomy compared to liposuction technique.

BACKGROUND: Gynecomastia is a benign enlargement of the male breast. Yet enlarged breasts cause anxiety, embarrassment, psychosocial discomfort, and fear of breast cancer. The aim of this study was to assess the experience of gynecomastia patients undergoing mastectomy and liposuction surgery. METHODS: Seven hundred thirty-three patients were analyzed for age, chief complaint, position, grade, operation approach, biopsy, and complication between mastectomy group and liposuction group, from 1990 to 2010. RESULTS: Four hundred two patients (436 breasts) were treated with mastectomy and 331 patients (386 breasts) were treated with liposuction techniques. Three hundred thirty (82%) patients complained of breast lump and lump with pain in mastectomy group, and 204 (61%) patients complained of enlargement breast and enlargement with pain in liposuction group (P < 0.05). All excision specimens were performed for routine histological analysis which showed pathologic diagnosis in patients with mastectomy (100%). One hundred fifty-nine (41%) patients with liposuction acquired pathologic diagnosis through fine needle aspiration and/or core biopsy (P < 0.05). The reoperation rates in mastectomy group and liposuction group were 1.4% and 0.5%, respectively. There were no nipple/areola necrosis and scars in liposuction group. CONCLUSIONS: The surgical treatment of gynecomastia required an individual approach, depending on symptoms (lump or enlargement) and requirements of patients. Patients who chose mastectomy were looking for reassurance that their pathologic diagnosis was benign. The increase in the number of liposuction patients was reflected in our study because it was associated with superior esthetic results and few complications.

Unique clinicopathological features of metaplastic breast carcinoma compared with invasive ductal carcinoma and poor prognostic indicators.

BACKGROUND: Metaplastic breast carcinoma is a rare aggressive malignant neoplasm. The purposes of this study are to review the pathologic features and clinical outcomes of metaplastic breast carcinoma compared to invasive ductal carcinoma and to evaluate the prognosis of metaplastic breast carcinoma. METHODS: The cases of 55 patients with metaplastic breast carcinoma presenting between 1991 and 2006 were analyzed and compared to the cases of 767 age-matched patients with invasive ductal carcinoma from the same time period. RESULTS: The group of patients with metaplastic breast carcinoma presented with a larger tumor size, lower lymph node involvement, higher percentage of triple-negative (estrogen receptor-, progesterone receptor- and human epidermal growth factor receptor-2-negative) cases, and Ki-67 over-expression compared with the group of patients with invasive ductal carcinoma and triple-negative invasive ductal carcinomas. Patients in the metaplastic breast carcinoma group tended to have more local (often chest wall) recurrences (P = 0.038) and distant (often lung) metastases (P = 0.001) than those in the invasive ductal carcinomas group. The prognosis of metaplastic breast carcinoma was poorer than that of invasive ductal carcinoma and triple-negative invasive ductal carcinomas; the 5-year overall survival rate was 54.5% in metaplastic breast carcinoma versus 85.1% in invasive ductal carcinoma, and 73.3% in triple-negative invasive ductal carcinomas (P <0.001). The 5-year disease-free survival rate was 45.5% in metaplastic breast carcinoma versus 71.2% in invasive ductal carcinoma, and 60.3% in triple-negative invasive ductal carcinomas (P <0.001). Multivariate analysis revealed tumor size larger than 5.0 cm, lymph node involvement and Ki-67≥14% were significantly related to 5-year overall survival (P = 0.010; P = 0.010; P = 0.035) and 5-year disease-free survival (P = 0.020; P = 0.018; P = 0.049). CONCLUSIONS: Metaplastic breast carcinoma shows a poorer prognosis than both invasive ductal carcinoma and triple-negative invasive ductal carcinomas. Tumor size larger than 5.0 cm, lymph node involvement and Ki-67 ≥14% indicate a poor prognosis in patients with metaplastic breast carcinoma.

Promoter hypermethylation of ARID1A gene is responsible for its low mRNA expression in many invasive breast cancers.

ARID1A (AT-rich interactive domain 1A) has recently been identified as a tumor suppressor gene. Its mRNA expression is significantly low in many breast cancers; this is often associated with more aggressive phenotypes. However, the underlying molecular mechanism for its low expression has not been fully understood. This study was undertaken to evaluate the contribution of gene copy number variation, mutations, promoter methylation and histone modification to ARID1A's low expression. 38 pairs of breast invasive ductal carcinomas and their normal breast tissue counterparts from the same patients were randomly selected for gene expression and copy number variation detection. Promoter methylation and histone modification levels were evaluated by MeDIP-qPCR and ChIP-qPCR, respectively. PCR product Sanger sequencing was carried out to detect the exon mutation rate. Twenty-two out of 38 invasive ductal carcinomas in the study (57.9%) revealed ARID1A mRNA low expression by realtime RT-PCR. The relative promoter methylation level was, significantly higher in ARID1A mRNA low expression group compared with its high expression group (p<0.001). In the low expression group, nineteen out of 22 invasive ductal carcinomas (86.4%) exhibited ARID1A promoter hypermthylation. In addition, the promoter hypermethylation was accompanied with repressive histone modification (H3K27Me3). Although five out of 38 invasive ductal carcinomas (13.2%) exhibited loss of ARID1A gene copy number by realtime PCR and nine exon novel mutations are seen from eight out of 33 invasive ductal carcinomas (24.2%), there was no statistically significant difference in both ARID1A mRNA low and high expression groups (p=0.25,and p=0.68, respectively). We demonstrate that promoter hypermethylation was the main culprit for ARID1A mRNA low expression in invasive ductal carcinomas. The influence of mutation and copy number variation on the expression were statistically insignificant at mRNA level, and were, therefore, not considered the main causes for ARID1A mRNA low expression in invasive breast cancer.

Long CAG repeat sequence and protein expression of androgen receptor considered as prognostic indicators in male breast carcinoma.

BACKGROUND: The androgen receptor (AR) expression and the CAG repeat length within the AR gene appear to be involved in the carcinogenesis of male breast carcinoma (MBC). Although phenotypic differences have been observed between MBC and normal control group in AR gene, there is lack of correlation analysis between AR expression and CAG repeat length in MBC. The purpose of the study was to investigate the prognostic value of CAG repeat lengths and AR protein expression. METHODS: 81 tumor tissues were used for immunostaining for AR expression and CAG repeat length determination and 80 normal controls were analyzed with CAG repeat length in AR gene. The CAG repeat length and AR expression were analyzed in relation to clinicopathological factors and prognostic indicators. RESULTS: AR gene in many MBCs has long CAG repeat sequence compared with that in control group (P = 0.001) and controls are more likely to exhibit short CAG repeat sequence than MBCs. There was statistically significant difference in long CAG repeat sequence between AR status for MBC patients (P = 0.004). The presence of long CAG repeat sequence and AR-positive expression were associated with shorter survival of MBC patients (CAG repeat: P = 0.050 for 5y-OS; P = 0.035 for 5y-DFS AR status: P = 0.048 for 5y-OS; P = 0.029 for 5y-DFS, respectively). CONCLUSION: The CAG repeat length within the AR gene might be one useful molecular biomarker to identify males at increased risk of breast cancer development. The presence of long CAG repeat sequence and AR protein expression were in relation to survival of MBC patients. The CAG repeat length and AR expression were two independent prognostic indicators in MBC patients.

Tamoxifen adherence and its relationship to mortality in 116 men with breast cancer.

Recent studies have revealed that many, perhaps most women with hormone-responsive breast cancer have low adherence to tamoxifen adjuvant hormonal therapy. However, limited data are available on tamoxifen adherence in male breast cancer (MBC) patients. The goal of this study was to assess tamoxifen adherence and its relationship to mortality in MBC patients. A cohort of 116 men who were diagnosed with receptor-positive breast cancer between June 1987 and July 2012 was recruited for the study using the cancer prevention and treatment system database of Heilongjiang Province. From the 116 patients who received a five-year tamoxifen prescription, only 64.6 % were still taking their medication 1 year later, and this percentage decreased to 46.4 and 28.7 % after 2 and 3 years, respectively, to 25.8 % after 4 years, and to 17.7 % in the last year. After multivariate adjustment, factors that significantly decreased tamoxifen adherence were low social support [Hazard ratio (HR) = 2.45, 95 % CI 1.32-4.55], age (HR = 1.10, 95 % CI 1.01-1.21), and adverse effects (HR = 2.19, 95 % CI 1.57-3.04). The primary endpoints in the adherence or low-adherence groups from this study were overall survival (OS) and disease-free survival (DFS) of the MBC patients. The five- and ten-year OS of the patients was 97.9 and 79.6 %, respectively, in the adherence group, and 84.7 and 50.4 %, respectively, in the low-adherence group (p = 0.008). The five- and ten-year DFS of the patients was 95.4 and 72.8 %, respectively, in the adherence group, and 72.6 and 42.3 %, respectively, in the low-adherence group (p = 0.007). The consequences of low treatment adherence in men, who have a potentially long life expectancy, may be significant. In light of these findings, there is an urgent need to acknowledge and tackle the issue of tamoxifen adherence in this patient group.