Clinicopathological significance of forkhead box protein A1 in breast cancer: A meta-analysis

Forkhead box proteins as the critical regulators of cisplatin response in tumor cells

Cisplatin (CDDP) is one of the most common chemotherapy drugs used in a wide range of cancer patients; however, there is a high rate of CDDP resistance among cancer patients. Considering the side effects of cisplatin in normal tissues, it is necessary to predict the CDDP response in cancer patients. Therefore, identifying the molecular mechanisms involved in CDDP resistance can help to introduce the prognostic markers. Several molecular mechanisms such as apoptosis inhibition, drug efflux, drug detoxification, and increased DNA repair are involved in CDDP resistance. Regarding the key role of transcription factors in regulation of many cellular processes related to drug resistance, in the present review, we discussed the role of Forkhead box (FOX) protein family in CDDP response. It has been reported that FOX proteins mainly promote CDDP resistance through the regulation of DNA repair, autophagy, epithelial-mesenchymal transition (EMT), and signaling pathways. Therefore, FOX proteins can be introduced as the prognostic markers to predict CDDP response in cancer patients. In addition, considering that oncogenic role of FOX proteins, the CDDP treatment along with FOX inhibition can be used as a therapeutic strategy in cancer patients.

Molecular mechanisms of the microRNA-132 during tumor progressions

Cancer as one of the leading causes of human deaths has always been one of the main health challenges in the world. Despite recent advances in therapeutic and diagnostic methods, there is still a high mortality rate among cancer patients. Late diagnosis is one of the main reasons for the high ratio of cancer related deaths. Therefore, it is required to introduce novel early detection methods. Various molecular mechanisms are associated with the tumor progression and metastasis. MicroRNAs (miRNAs) are a class of non-coding RNAs (ncRNAs) family that has important functions in regulation of the cellular processes such as cell proliferation, apoptosis, and tumor progression. Moreover, they have higher stability in body fluids compared with mRNAs which can be introduced as non-invasive diagnostic markers in cancer patients. MiR-132 has important functions as tumor suppressor or oncogene in different cancers. In the present review, we have summarized all of the studies which have been reported the role of miR-132 during tumor progressions. We categorized the miR-132 target genes based on their cell and molecular functions. Although, it has been reported that the miR-132 mainly functions as a tumor suppressor, it has also oncogenic functions especially in pancreatic tumors. MiR-132 mainly exerts its roles during tumor progressions by regulation of the transcription factors and signaling pathways. Present review clarifies the tumor specific molecular mechanisms of miR-132 to introduce that as an efficient non-invasive diagnostic marker in various cancers.

Time-varying effects of FOXA1 on breast cancer prognosis

PURPOSE

Results of previous studies on the associations between Forkhead box A1 (FOXA1) expression in breast cancer tissues and the prognosis varied depending on the follow-up durations. The present study would investigate whether there is a time-varying effect of FOXA1 in breast cancer tissues on the prognosis.

METHODS

FOXA1 expressions were evaluated in 1041 primary invasive breast tumors with tissue microarrays by immunohistochemistry. Cox models with restricted cubic splines and Kaplan-Meier survival analysis were used to examine the associations between FOXA1 and the prognosis. Flexible parametric models were applied to explore the time-varying effect of FOXA1.

RESULTS

Overall, the association between FOXA1 expression and the prognosis was not significant but varied on the time of follow-up. Compared to FOXA1 ≤ 270 of H-score, the hazard ratios (HRs) of death for those with 271-285 of FOXA1 expression increased from 0.35 (95% CI 0.14-0.86) at 6 months after diagnosis to 2.88 (95% CI 1.35-6.15) at 120 months with a crossover at around 36 months. Similar patterns were also observed for FOXA1 > 285 of H-score and for progression free survival (PFS). Moreover, when allowed both FOXA1 and estrogen receptor (ER) to change over time in the model (considering that ER had a similar time-varying effect), these time-varying effects remained for FOXA1 on both overall survival (OS) (P < 0.01) and PFS (P = 0.01) but were attenuated for ER (P = 0.13 for OS).

CONCLUSIONS

This study revealed an independent time-varying effect of FOXA1 on breast cancer prognosis, which would provide an insight into the roles of FOXA1 as a marker of breast cancer prognosis and may help optimize the medication strategies.

FOXA1 expression in Iraqi women with ER+ breast cancer

Background: Breast cancer (BC) is a heterogeneous disease that can be classified into many subtypes according to histopathological and molecular characteristics. Forkhead box protein A1 (FOXA1) is a transcriptional pioneer factor that opens chromatin allowing estrogen receptor (α-ER) access to its genomic targets. FOXA1 expression is related to luminal BC with a good prognosis. Objectives: The present study is sought to determine the FOXA1 expression in Iraqi women with ER+ BC. Methods: Forty-eight fresh malignant breast tissues were analyzed by immunohistochemistry assay to choose ER+ samples, and then by RT-qPCR to evaluate FOXA1 gene expression. Results: The ER-positive samples were (72.91%) of the total samples, and the molecular subtype of luminal A was the most common with a percentage of 56.25%. It was also noted that the high expression of the FOXA1 gene is highly significant (p<0.05) in Iraqi women with BC when compared with healthy controls. Conclusions: Highly significant FOXA1 expression was found in Iraqi women with BC makes it eligible to be a good predictor or a biomarker for BC.

FOXA1 Expression in Nasopharyngeal Carcinoma: Association with Clinicopathological Characteristics and EMT Markers

The forkhead box (FOXA) family of transcription factors regulates gene expression and chromatin structure during tumorigenesis and embryonic development. Until now, the relationship between FOXA1 and the nasopharyngeal carcinoma (NPC) has not yet been reported. Therefore, our purpose is to analyze the expression of FOXA1 in 56 NPC patients compared to 10 normal nasopharyngeal mucosae and to correlate the expression with the clinicopathological features. Besides, we investigated the association between FOXA1 and LMP1 gene expression, as well as the EMT markers namely the E-cadherin and Twist1. Among 56 NPC tissues, 34 (60.7%) cases were positive for FOXA1. Furthermore, we noticed that FOXA1 expression correlated with TNM (p = 0.037), and age at diagnosis (p = 0.05). Moreover, positive expression of FOXA1 is likely to be associated with prolonged disease-free survival and overall survival rates. On the other hand, we observed a positive association between the expression of E-cadherin and FOXA1 (p = 0.0051) whereas Twist1 correlated negatively with FOXA1 (p = 0.004). Furthermore, knowing that LMP1 plays a key role in the pathogenesis of NPC, we explored the association of FOXA1 with the LMP1 gene expression in both NPC cell lines and tissues. We found that, in the C666-1 which displays low levels of LMP1, the expression of FOXA1 is high, and inversely in the C15 cell line that expresses a high level of LMP1, the level of FOXA1 is low. Besides, in accordance to our results, we found that in NPC tissues there is a negative association between LMP1 and FOXA1. In conclusion, our results suggest that the overexpression of FOXA1 is associated with a nonaggressive behavior and favorable prognosis in NPC patients. FOXA1 could contribute in the EMT process through key factors as E-cadherin, Twist1, and LMP1.

Androgen receptor and FOXA1 coexpression define a "luminal-AR" subtype of feline mammary carcinomas, spontaneous models of breast cancer

Background

Invasive mammary carcinomas that spontaneously develop in female cats are associated with high mortality, and resemble the most aggressive human breast cancers, especially triple-negative breast cancer (TNBC). Transcriptome studies showed that TNBCs are a heterogeneous group that includes a potentially hormone-dependent subtype named luminal-AR. Some authors proposed an immunohistochemical definition of the luminal-AR subtype, which is not only positive for Androgen Receptor (AR), but also either positive for the transcription factor Forkhead box A1 (FOXA1), or negative for basal markers. The objectives of this study were to describe AR and FOXA1 expressions in feline mammary carcinomas (FMCs), their prognostic value, and if their coexpression could define a “luminal-AR” subtype of triple-negative mammary carcinomas in cats.

Methods

In a previously described retrospective cohort of 180 female cats with FMCs, with a 2-year follow-up post-mastectomy, we assessed AR, FOXA1, ER, PR, Ki-67, HER2, and CK14 expressions by automated immunohistochemistry.

Results

Of the 180 FMCs, 57 (32%) were luminal; i.e., ER and/or PR positive, and 123 (68%) were triple-negative (ER–, PR– and HER2–) FMCs. AR overexpression (found in 33 cases/180, 18%) and FOXA1 index ≥1% (64/180, 36%) were associated with a longer disease-free interval, overall survival, and cancer-specific survival in cats with FMC. Analysis of AR, FOXA1 and CK14 coexpression in triple-negative FMCs showed that AR+ triple-negative FMCs were heterogeneous: there existed an AR+ FOXA1+ CK14– subgroup (n = 7) associated with a better cancer-specific survival by multivariate survival analysis (HR = 0.26, 95% CI: 0.07–0.89, p = 0.03) compared to AR+ FOXA1–CK14+ triple-negative FMCs (n = 46) (HR = 1.00), independently of the pathologic tumor size and pathologic nodal stage. The non-basal-like subtype of triple-negative FMCs that coexpresses AR and FOXA1 (the AR+ FOXA1+ CK14– subgroup) could represent the equivalent of the luminal-AR subgroup of human triple-negative breast cancer.

Conclusions

We identified an AR+ FOXA1+ CK14– subgroup of triple-negative FMCs that might correspond to the luminal-AR subgroup of human triple-negative breast cancers. Cats with FMC may be interesting spontaneous animal models to investigate new strategies targeting the androgen receptor, especially in the aggressive subtype of AR+ basal-like triple-negative mammary carcinomas with loss of FOXA1 expression (the AR+ FOXA1–CK14+ subgroup).

FOXA1 and AR in invasive breast cancer: new findings on their co-expression and impact on prognosis in ER-positive patients

Background

The role of forkhead-box A1 (FOXA1) and Androgen receptor (AR) in breast cancer (BC) has been extensively studied. However, the prognostic role of their co-expression in Estrogen receptor positive (ER+) BC has not been investigated so far. The aim of the present study was thus to assess the co-expression (protein and mRNA) of FOXA1 and AR in BC patients, in order to evaluate their prognostic impact according to ER status.

Methods

Immunohistochemical expression of AR and FOXA1 was evaluated on 479 consecutive BC, with complete clinical-pathological and follow up data. Fresh-frozen tissues from 65 cases were available. The expression of AR and FOXA1 with ER was validated using mRNA analyses. Survival and Cox proportional hazard analyses were used to evaluate the relationship between FOXA1, AR and prognosis.

Results

Expression of ER, AR and FOXA1 was observed in 78, 60 and 85% of cases respectively. Most AR+ cases (97%) were also FOXA1+. The level of FOXA1 mRNA positively correlated with level of both AR mRNA (r = 0.8975; P < 0.001) and ER mRNA (r = 0.7326; P < 0.001). In ER+ BC, FOXA1 was associated with a good prognosis independently of AR expression in the three subgroups analyzed (FOXA1+/AR+; FOXA1+/AR-; FOXA1−/AR-). Multivariate analyses confirmed that FOXA1 may provide more information than AR in Disease-Free Interval (DFI) of ER+ BC patients.

Conclusion

Our results suggest that in BC the expression of FOXA1 is directly related to the expression of AR. Despite that, FOXA1 is found as superior predicting marker of recurrences compared to AR in ER+ BC patients.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4624-y) contains supplementary material, which is available to authorized users.

MicroRNAs as regulators and mediators of forkhead box transcription factors function in human cancers

Evidence has shown that microRNAs are widely implicated as indispensable components of tumor suppressive and oncogenic pathways in human cancers. Thus, identification of microRNA targets and their relevant pathways will contribute to the development of microRNA-based therapeutics. The forkhead box transcription factors regulate numerous processes including cell cycle progression, metabolism, metastasis and angiogenesis, thereby facilitating tumor initiation and progression. A complex network of protein and non-coding RNAs mediates the expression and activity of forkhead box transcription factors. In this review, we summarize the current knowledge and concepts concerning the involvement of microRNAs and forkhead box transcription factors and describe the roles of microRNAs-forkhead box axis in various disease states including tumor initiation and progression. Additionally, we describe some of the technical challenges in the use of the microRNA-forkhead box signaling pathway in cancer treatment.

The transcription factor FOXA1 induces epithelial ovarian cancer tumorigenesis and progression

FOXA1 (forkhead box A1), a member of the FOXA transcription factor superfamily, plays an important role in tumor occurrence and development. However, the relationship between FOXA1 and ovarian cancer has not been reported. We examined normal ovarian tissue and ovarian cancer tissue and found increased FOXA1 expression in the cancer tissue. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and flow cytometry assays demonstrated that transfection with small interfering RNA to silence FOXA1 (si-FOXA1) in ovarian cancer cell lines decreased cell proliferation and induced apoptosis and S-phase arrest. In addition, si-FOXA1 transfection inhibited cell migration and invasion. Western blotting showed that si-FOXA1 transfection decreased the levels of YY1-associated protein 1, cyclin-dependent kinase 1, cyclin D1, phosphatidylinositol-3 kinase, E2F transcription factor 1, B-cell lymphoma 2, and vascular endothelial growth factor A protein. Based on these results, we suggest that FOXA1 plays a catalytic role in ovarian cancer pathogenesis and development by affecting the expression of the above-mentioned proteins.

Characterisation of male breast cancer: a descriptive biomarker study from a large patient series

Male breast cancer (MBC) is rare. We assembled 446 MBCs on tissue microarrays and assessed clinicopathological information, together with data from 15 published studies, totalling 1984 cases. By immunohistochemistry we investigated 14 biomarkers (ERα, ERβ1, ERβ2, ERβ5, PR, AR, Bcl-2, HER2, p53, E-cadherin, Ki67, survivin, prolactin, FOXA1) for survival impact. The main histological subtype in our cohort and combined analyses was ductal (81%, 83%), grade 2; (40%, 44%), respectively. Cases were predominantly ERα (84%, 82%) and PR positive (74%, 71%), respectively, with HER2 expression being infrequent (2%, 10%), respectively. In our cohort, advanced age (>67) was the strongest predictor of overall (OS) and disease free survival (DFS) (p = 0.00001; p = 0.01, respectively). Node positivity negatively impacted DFS (p = 0.04). FOXA1 p = 0.005) and AR p = 0.009) were both positively prognostic for DFS, remaining upon multivariate analysis. Network analysis showed ERα, AR and FOXA1 significantly correlated. In summary, the principle phenotype of MBC was luminal A, ductal, grade 2. In ERα+ MBC, only AR had prognostic significance, suggesting AR blockade could be employed therapeutically.