Therapeutically Targeting Cancers That Overexpress FOXC1: A Transcriptional Driver of Cell Plasticity, Partial EMT, and Cancer Metastasis.

Metastasis accounts for more than 90% of cancer related mortality, thus the most pressing need in the field of oncology today is the ability to accurately predict future onset of metastatic disease, ideally at the time of initial diagnosis. As opposed to current practice, what would be desirable is that prognostic, biomarker-based detection of metastatic propensity and heightened risk of cancer recurrence be performed long before overt metastasis has set in. Without such timely information it will be impossible to formulate a rational therapeutic treatment plan to favorably alter the trajectory of disease progression. In order to help inform rational selection of targeted therapeutics, any recurrence/metastasis risk prediction strategy must occur with the paired identification of novel prognostic biomarkers and their underlying molecular regulatory mechanisms that help drive cancer recurrence/metastasis (i.e. recurrence biomarkers). Traditional clinical factors alone (such as TNM staging criteria) are no longer adequately prognostic for this purpose in the current molecular era. FOXC1 is a pivotal transcription factor that has been functionally implicated to drive cancer metastasis and has been demonstrated to be an independent predictor of heightened metastatic risk, at the time of initial diagnosis. In this review, we present our viewpoints on the master regulatory role that FOXC1 plays in mediating cancer stem cell traits that include cellular plasticity, partial EMT, treatment resistance, cancer invasion and cancer migration during cancer progression and metastasis. We also highlight potential therapeutic strategies to target cancers that are, or have evolved to become, "transcriptionally addicted" to FOXC1. The potential role of FOXC1 expression status in predicting the efficacy of these identified therapeutic approaches merits evaluation in clinical trials.

Anosmia, Ageusia and COVID-19.

COVID-19 is certainly the greatest global health problem now and for the foreseeable future. Clinicians and scientists from all over the world have been producing evidence to understand the epidemiology, clinical profile and prognostic factors of COVID-19. In the last six months a large list of COVID-19 symptoms including loss of taste and smell have emerged which can be used for screening and risk stratification. Robust workup of this evidence will help to reach strong conclusions to advance clinical medicine, epidemiology, public health, immunology and evidence-based treatment options in the spectrum of disease that we now know as COVID-19.

Superior breast cancer metastasis risk stratification using an epithelial-mesenchymal-amoeboid transition gene signature.

BACKGROUND: Cancer cells are known to display varying degrees of metastatic propensity, but the molecular basis underlying such heterogeneity remains unclear. Our aims in this study were to (i) elucidate prognostic subtypes in primary tumors based on an epithelial-to-mesenchymal-to-amoeboid transition (EMAT) continuum that captures the heterogeneity of metastatic propensity and (ii) to more comprehensively define biologically informed subtypes predictive of breast cancer metastasis and survival in lymph node-negative (LNN) patients. METHODS: We constructed a novel metastasis biology-based gene signature (EMAT) derived exclusively from cancer cells induced to undergo either epithelial-to-mesenchymal transition (EMT) or mesenchymal-to-amoeboid transition (MAT) to gauge their metastatic potential. Genome-wide gene expression data obtained from 913 primary tumors of lymph node-negative breast cancer (LNNBC) patients were analyzed. EMAT gene signature-based prognostic stratification of patients was performed to identify biologically relevant subtypes associated with distinct metastatic propensity. RESULTS: Delineated EMAT subtypes display a biologic range from less stem-like to more stem-like cell states and from less invasive to more invasive modes of cancer progression. Consideration of EMAT subtypes in combination with standard clinical parameters significantly improved survival prediction. EMAT subtypes outperformed prognosis accuracy of receptor or PAM50-based BC intrinsic subtypes even after adjusting for treatment variables in 3 independent, LNNBC cohorts including a treatment-naïve patient cohort. CONCLUSIONS: EMAT classification is a biologically informed method that provides prognostic information beyond that which can be provided by traditional cancer staging or PAM50 molecular subtype status and may improve metastasis risk assessment in early stage, LNNBC patients, who may otherwise be perceived to be at low metastasis risk.

Functional and prognostic significance of long non-coding RNA MALAT1 as a metastasis driver in ER negative lymph node negative breast cancer.

MALAT1 (metastasis associated lung adenocarcinoma transcript1) is a conserved long non-coding RNA, known to regulate gene expression by modulating transcription and post-transcriptional pre-mRNA processing of a large number of genes. MALAT1 expression is deregulated in various tumors, including breast cancer. However, the significance of such abnormal expression is yet to be fully understood. In this study, we demonstrate that regulation of aggressive breast cancer cell traits by MALAT1 is not predicted solely based on an elevated expression level but is context specific. By performing loss- and gain-of-function studies, both under in vitro and in vivo conditions, we demonstrate that MALAT1 facilitates cell proliferation, tumor progression and metastasis of triple-negative breast cancer (TNBC) cells despite having a comparatively lower expression level than ER or HER2-positive breast cancer cells. Furthermore, MALAT1 regulates the expression of several cancer metastasis-related genes, but displays molecular subtype specific correlations with such genes. Assessment of the prognostic significance of MALAT1 in human breast cancer (n=1992) revealed elevated MALAT1 expression was associated with decreased disease-specific survival in ER negative, lymph node negative patients of the HER2 and TNBC molecular subtypes. Multivariable analysis confirmed MALAT1 to have independent prognostic significance in the TNBC lymph node negative patient subset (HR=2.64, 95%CI 1.35- 5.16, p=0.005). We propose that the functional significance of MALAT1 as a metastasis driver and its potential use as a prognostic marker is most promising for those patients diagnosed with ER negative, lymph node negative breast cancer who might otherwise mistakenly be stratified to have low recurrence risk.

Intraoperative optical coherence tomography for assessing human lymph nodes for metastatic cancer.

BACKGROUND: Evaluation of lymph node (LN) status is an important factor for detecting metastasis and thereby staging breast cancer. Currently utilized clinical techniques involve the surgical disruption and resection of lymphatic structure, whether nodes or axillary contents, for histological examination. While reasonably effective at detection of macrometastasis, the majority of the resected lymph nodes are histologically negative. Improvements need to be made to better detect micrometastasis, minimize or eliminate lymphatic disruption complications, and provide immediate and accurate intraoperative feedback for in vivo cancer staging to better guide surgery. METHODS: We evaluated the use of optical coherence tomography (OCT), a high-resolution, real-time, label-free imaging modality for the intraoperative assessment of human LNs for metastatic disease in patients with breast cancer. We assessed the sensitivity and specificity of double-blinded trained readers who analyzed intraoperative OCT LN images for presence of metastatic disease, using co-registered post-operative histopathology as the gold standard. RESULTS: Our results suggest that intraoperative OCT examination of LNs is an appropriate real-time, label-free, non-destructive alternative to frozen-section analysis, potentially offering faster interpretation and results to empower superior intraoperative decision-making. CONCLUSIONS: Intraoperative OCT has strong potential to supplement current post-operative histopathology with real-time in situ assessment of LNs to preserve both non-cancerous nodes and their lymphatic vessels, and thus reduce the associated risks and complications from surgical disruption of lymphoid structures following biopsy.

Carotenoid Nanovector for Efficient Therapeutic Gene Knockdown of Transcription Factor FOXC1 in Liver Cancer.

Transcription factor FOXC1 has been implicated to play a critical role in hepatocellular carcinoma (HCC) progression, but targeting FOXC1 for therapeutic benefit remains a challenge owing to its location inside the cell nucleus. Herein we report successful therapeutic gene knockdown of transcription factor FOXC1 in liver cancer cells through efficient delivery of siFOXC1 using novel carotenoid functionalized dendritic nanoparticles (CDN). This delivery system also displayed a markedly reduced toxicity profile compared to a standard siRNA transfection agent. We were able to achieve ∼90% FOXC1 knockdown using the CDN-siFOXC1 complex. Additionally, it was found to have ∼18% greater delivery efficiency compared to treatments with particles which have no carotenoid tagging, thereby emphasizing the role of carotenoid mediated cell internalization in the efficient delivery of CDN-siFOXC1 complex in liver cancer cells.

FOXC1 Activates Smoothened-Independent Hedgehog Signaling in Basal-like Breast Cancer.

The mesoderm- and epithelial-mesenchymal transition-associated transcription factor FOXC1 is specifically overexpressed in basal-like breast cancer (BLBC), but its biochemical function is not understood. Here, we demonstrate that FOXC1 controls cancer stem cell (CSC) properties enriched in BLBC cells via activation of Smoothened (SMO)-independent Hedgehog (Hh) signaling. This non-canonical activation of Hh is specifically mediated by Gli2. Furthermore, we show that the N-terminal domain of FOXC1 (aa 1-68) binds directly to an internal region (aa 898-1168) of Gli2, enhancing the DNA-binding and transcription-activating capacity of Gli2. FOXC1 expression correlates with that of Gli2 and its targets in human breast cancers. Moreover, FOXC1 overexpression reduces sensitivity to anti-Hedgehog (Hh) inhibitors in BLBC cells and xenograft tumors. Together, these findings reveal FOXC1-mediated non-canonical Hh signaling that determines the BLBC stem-like phenotype and anti-Hh sensitivity, supporting inhibition of FOXC1 pathways as potential approaches for improving BLBC treatment.

Trimodal Therapy: Combining Hyperthermia with Repurposed Bexarotene and Ultrasound for Treating Liver Cancer.

Repurposing of existing cancer drugs to overcome their physical limitations, such as insolubility, represents an attractive strategy to achieve enhanced therapeutic efficacy and broaden the range of clinical applications. Such an approach also promises to offer substantial cost savings in drug development efforts. Here we repurposed FDA-approved topical agent bexarotene (Targretin), currently in limited use for cutaneous manifestations of T-cell lymphomas, and re-engineer it for use in solid tumor applications by forming self-assembling nanobubbles. Physico-chemical characterization studies of the novel prodrug nanobubbles demonstrated their stability, enhanced target cell internalization capability, and highly controlled release profile in response to application of focused ultrasound energy. Using an in vitro model of hepatocellular carcinoma and an in vivo large animal model of liver ablation, we demonstrate the effectiveness of bexarotene prodrug nanobubbles when used in conjunction with catheter-based ultrasound, thereby highlighting the therapeutic promise of this trimodal approach.

Real-time Imaging of the Resection Bed Using a Handheld Probe to Reduce Incidence of Microscopic Positive Margins in Cancer Surgery.

Wide local excision (WLE) is a common surgical intervention for solid tumors such as those in melanoma, breast, pancreatic, and gastrointestinal cancer. However, adequate margin assessment during WLE remains a significant challenge, resulting in surgical reinterventions to achieve adequate local control. Currently, no label-free imaging method is available for surgeons to examine the resection bed in vivo for microscopic residual cancer. Optical coherence tomography (OCT) enables real-time high-resolution imaging of tissue microstructure. Previous studies have demonstrated that OCT analysis of excised tissue specimens can distinguish between normal and cancerous tissues by identifying the heterogeneous and disorganized microscopic tissue structures indicative of malignancy. In this translational study involving 35 patients, a handheld surgical OCT imaging probe was developed for in vivo use to assess margins both in the resection bed and on excised specimens for the microscopic presence of cancer. The image results from OCT showed structural differences between normal and cancerous tissue within the resection bed following WLE of the human breast. The ex vivo images were compared with standard postoperative histopathology to yield sensitivity of 91.7% [95% confidence interval (CI), 62.5%-100%] and specificity of 92.1% (95% CI, 78.4%-98%). This study demonstrates in vivo OCT imaging of the resection bed during WLE with the potential for real-time microscopic image-guided surgery.

Stain-less staining for computed histopathology.

Dyes such as hematoxylin and eosin (H&E) and immunohistochemical stains have been increasingly used to visualize tissue composition in research and clinical practice. We present an alternative approach to obtain the same information using stain-free chemical imaging. Relying on Fourier transform infrared (FT-IR) spectroscopic imaging and computation, stainless computed histopathology can enable a rapid, digital, quantitative and non-perturbing visualization of morphology and multiple molecular epitopes simultaneously in a variety of research and clinical pathology applications.

Diagnosis of Basal-Like Breast Cancer Using a FOXC1-Based Assay.

BACKGROUND: Diagnosis of basal-like breast cancer (BLBC) remains a bottleneck to conducting effective clinical trials for this aggressive subtype. We postulated that elevated expression of Forkhead Box transcription factor C1 (FOXC1) is a simple and accurate diagnostic biomarker for BLBC. METHODS: Accuracy of FOXC1 expression in identifying BLBC was compared with the PAM50 gene expression panel in gene expression microarray (GEM) (n = 1992) and quantitative real-time polymerase chain reaction (qRT-PCR) (n = 349) datasets. A FOXC1-based immunohistochemical (IHC) assay was developed and assessed in 96 archival formalin-fixed, paraffin-embedded (FFPE) breast cancer samples that also underwent PAM50 profiling. All statistical tests were two-sided. RESULTS: A FOXC1-based two-tier assay (IHC +/- qRT-PCR) accurately identified BLBC (AUC = 0.88) in an independent cohort of FFPE samples, validating the accuracy of FOXC1-defined BLBC in GEM (AUC = 0.90) and qRT-PCR (AUC = 0.88) studies, when compared with platform-specific PAM50-defined BLBC. The hazard ratio (HR) for disease-specific survival in patients having FOXC1-defined BLBC was 1.71 (95% CI = 1.31 to 2.23, P < .001), comparable to PAM50 assay-defined BLBC (HR = 1.74, 95% CI = 1.40 to 2.17, P < .001). FOXC1 expression also predicted the development of brain metastasis. Importantly, unlike triple-negative or Core Basal IHC definitions, a FOXC1-based definition is able to identify BLBC in both ER+ and HER2+ patients. CONCLUSION: A FOXC1-based two-tier assay, by virtue of being rapid, simple, accurate, and cost-effective may emerge as the diagnostic assay of choice for BLBC. Such a test could substantially improve clinical trial enrichment of BLBC patients and accelerate the identification of effective chemotherapeutic options for this aggressive disease.

Personalizing breast cancer staging by the inclusion of ER, PR, and HER2.

IMPORTANCE: Nonanatomic factors, such as histologic grade and biomarkers, can guide breast cancer management but are not included in the current TNM staging system. OBJECTIVE: To use as an example the triple-negative phenotype (TNP) defined by the absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 (HER2) to examine whether such inclusion improves the prognostic accuracy of TNM staging for breast cancer. DESIGN, SETTING, AND PARTICIPANTS: Women diagnosed with primary invasive ductal breast cancer from January 1, 1991, through December 31, 2008, were identified from a prospective institutional database. Excluded were patients who received neoadjuvant therapy, those whose staging information was incomplete, or those whose tumor lacked ER, PR, and HER2 data. Breast cancers were categorized by TNM stage and by the presence or absence of TNP. MAIN OUTCOMES AND MEASURES: Overall survival at 5 years. RESULTS: Database review identified 1842 consecutive eligible patients with breast cancer. When patients were stratified by TNM stage, overall survival curves for those with TNP breast cancer matched those for patients whose non-TNP breast cancer was 1 TNM stage higher. Multivariable analysis showed that TNP status was a powerful prognostic variable, and the likelihood ratio test revealed that the prognostic accuracy of the TNM staging system that incorporated TNP was superior to the current TNM staging system (P< .001). A TNM staging system that incorporated TNP reduced early-stage compression by 15%. CONCLUSIONS AND RELEVANCE: The internationally recognized and easily reproducible examination of ER, PR, and HER2 status exemplifies how nonanatomic factors can improve the prognostic accuracy of breast cancer staging.

High levels of secreted frizzled-related protein 1 correlate with poor prognosis and promote tumourigenesis in gastric cancer.

BACKGROUND: Secreted frizzled-related protein 1 (sFRP1), Wnt signalling regulator, can positively or negatively regulate tumourigenesis and progression. We sought to determine the clinical relevance and the role of sFRP1 in gastric cancer development and progression. METHODS: We investigated the sFRP1 protein expression levels and its clinicopathological correlations using 85 cases of human gastric samples with survival information (JWCI cohort). mRNA levels of sFRP1 and coexpressed genes were analysed using 131-sample cDNA microarray data (Ruijin cohort). The effects of sFRP1 alteration were investigated using cell proliferation, colony formation, migration, and invasion and xenograft models. RESULTS: We show that sFRP1 is overexpressed in some human cancers and is significantly associated with lymph node metastasis and decreased overall survival in gastric cancer patients. Using gastric cancer cell models, we demonstrate that sFRP1 overexpression is correlated with the activation of TGFß (transforming growth factor-beta) signalling pathway and thereby induces cell proliferation, epithelial-mesenchymal transition (EMT), and invasion. Conversely, sFRP1 knockdown shows the opposite effects. Furthermore, sFRP1 overexpression promotes tumourigenesis and metastasis in a xenograft model. CONCLUSION: Our studies demonstrate that sFRP1 is a biomarker for aggressive subgroups of human gastric cancer and a prognostic biomarker for patients with poor survival. Our data provide insight into a crosstalk between Wnt and TGFß pathways which underlies gastric cancer development and progression.

Ultrathin primary is a marker for worse prognosis in lymph node-positive cutaneous melanoma.

BACKGROUND: Lymph lymph node metastasis from melanoma ≤0.50 mm (ultrathin) is an infrequent event. However, because many newly diagnosed melanomas are ultrathin, a significant proportion of patients who present with lymph node disease have an ultrathin melanoma. The authors hypothesized that ultrathin melanomas that present with lymph node metastasis represent biologically aggressive lesions with a worse prognosis. METHODS: The Surveillance, Epidemiology, and End Results registry data were queried to identify patients with cutaneous melanoma who presented with lymph node metastasis diagnosed between 1998 and 2008. Hazard ratios (HRs) from Cox proportional hazards regression models were used to compare disease-specific survival (DSS) between various tumor depths. RESULTS: In total, 6134 patients with lymph node-positive melanoma were identified and stratified according to tumor depth, including 588 (10%) with a tumor depth ≤0.50 mm, 519 (8%) with a tumor depth from 0.51 to 1.00 mm, 1669 (27%) with a tumor depth from 1.01 to 2.00 mm, 1871 (31%) with a tumor depth from 2.01 to 4.00 mm, and 1487 (24%) with a tumor depth >4.00 mm; and the respective 5-year DSS rates were 63%, 76%, 75%, 60%, and 43%. Multivariable analysis confirmed a similar trend in HRs for DSS: The HR was 1.00 for a tumor depth ≤0.50 mm (reference category) and 0.64 (P < .001), 0.65 (P < .001), 0.95 (P = .57), and 1.42 (P < .001) for tumor depths of 0.51 to 1.00 mm, 1.01 to 2.00 mm, 2.01 to 4.00 mm, and >4.00 mm, respectively. This association of tumor depth with DSS persisted for N1 and N2 disease but not for N3 disease. CONCLUSIONS: Ultrathin melanoma (≤0.50 mm) was identified as a marker of poor prognosis in the setting of lymph node metastasis. These results may improve recommendations for adjuvant therapy, surveillance protocols, and risk stratification for clinical trials.

Prognostic value of basal phenotype in HER2-overexpressing breast cancer.

BACKGROUND: Primary breast cancers that overexpress human epidermal growth factor receptor 2 have variable biological features and clinical outcomes. A subgroup of HER2-overexpressing tumors that express basal-like immunohistochemical markers-the so-called basal-HER2+ subtype--is associated with poor prognosis. We investigated the clinical relevance of this basal-HER2+ subtype within HER2-overexpressing breast tumors. METHODS: Database review identified consecutive patients with HER2-overexpressing breast cancer. Archival tumor specimens from these patients were immunostained for estrogen receptor (ER), HER2, and basal cytokeratin (CK) expression, then subtyped as luminal-HER2+ (ER positive and basal CK negative), HER2+ (ER negative and basal CK negative), and basal-HER2+ (ER negative and basal CK positive). Subtypes were correlated with clinicopathologic features and overall survival. RESULTS: Immunohistochemical assessment of 131 HER2-overexpressing breast tumors identified 79 (60%) luminal-HER2+ tumors, 40 (31%) HER2+ tumors, and 12 (9%) basal-HER2+ tumors. There was no difference in the use of adjuvant trastuzumab and chemotherapy among patients with these subtypes. Five-year overall survival was 65% for patients with basal-HER2+ tumors versus 94% (P = 0.0035) and 96% (P = 0.0031) for patients with luminal-HER2+ and HER2+ tumors, respectively. The basal-HER2+ subtype was associated with the worst prognosis after adjusting for age, tumor size, lymph node status, and adjuvant treatment (hazard ratio 5.06, 95% confidence interval 1.1-23.2, P = 0.037). CONCLUSIONS: The basal-HER2+ subtype highlights the heterogeneous biology of HER2-overexpressing breast cancer. The basal-HER2+ subtype is independently associated with poor survival and may provide insight into breast cancer cell response to anti-HER2 therapy.

Basal-like breast cancer defined by FOXC1 expression offers superior prognostic value: a retrospective immunohistochemical study.

BACKGROUND: Basal-like breast cancer (BLBC) has a poor prognosis and is often identified by the triple-negative phenotype (TNP) and/or basal cytokeratins (CKs). Overexpression of mRNA for forkhead box C1 (FOXC1) transcription factor was recently identified as a pivotal prognostic biomarker of BLBC. We investigated the prognostic value of FOXC1 protein expression in invasive breast cancer and compared its prognostic significance to that of TNP and basal CKs. METHODS: Archived TNP specimens of primary invasive ductal breast cancer from 759 patients were examined by immunohistochemical staining for FOXC1, CK5/6, and CK14; prognostic significance was assessed using multivariate analyses. In addition, the impact of adding FOXC1 versus basal CKs to TNP-based BLBC assessment was assessed. RESULTS: FOXC1 protein expression was a significant predictor of overall survival on univariate (hazard ratio [HR] 3.364 95% confidence interval [CI] 1.758-6.438, P = 0.0002) and multivariate (HR 3.389 95% CI 1.928-7.645, P = 0.0001) analyses, despite its correlation with younger age (P = 0.0003). Interestingly, nodal status was not significant on multivariate analysis when FOXC1 expression status was included in the analysis. BLBC defined by TNP plus FOXC1 demonstrated superior prognostic relevance compared to BLBC defined by TNP or TNP plus basal CKs. CONCLUSIONS: Immunohistochemical detection of FOXC1 expression in TNP invasive breast cancer is an independent prognostic indicator that is superior to conventional immunohistochemical surrogates of BLBC. Prospective validation is warranted to further define the diagnostic, prognostic, and predictive utility of FOXC1 in breast cancer management and clinical trial design.

The florid subtype of lobular carcinoma in situ: marker or precursor for invasive lobular carcinoma?

BACKGROUND: Lobular carcinoma in situ (LCIS) is considered a risk factor-not a precursor-for both invasive lobular and ductal carcinoma. Florid LCIS (F-LCIS) is an architectural subtype of LCIS that does not express E-cadherin, yet has the histologic and often radiographic appearance of solid-type ductal carcinoma in situ (DCIS). Since DCIS is considered a precursor to invasive ductal carcinoma, should F-LCIS be considered a precursor to invasive lobular carcinoma (ILC)? METHODS: Review of an institutional database identified cases of LCIS and solid-type DCIS diagnosed by excisional biopsy, segmentectomy, or mastectomy between 1991 and 2000 to determine the prevalence of associated invasive breast cancer. Archival specimens were evaluated for florid and nonflorid LCIS, nuclear grade of LCIS, and the presence and subtype of invasive breast cancer. Solid-type DCIS that lacked E-cadherin expression was classified as F-LCIS. RESULTS: Of 210 consecutive specimens of LCIS examined, 171 had nonflorid LCIS (81%) and 39 had F-LCIS (19%). Nonflorid LCIS had a diffuse pattern, whereas F-LCIS appeared as discrete foci adjacent to ILC. An invasive component was identified with 87% of F-LCIS lesions versus 73% of nonflorid LCIS lesions (P = 0.064); this component was lobular in 100% of F-LCIS lesions versus 82% of nonflorid LCIS lesions, a significant difference (P = 0.0044) that persisted when the analysis was adjusted for nuclear grade (P = 0.0082). CONCLUSION: Its close spatial relationship to an invasive component and increased association with ILC suggest that F-LCIS may be a precursor for ILC.

Thioredoxin-like 2 regulates human cancer cell growth and metastasis via redox homeostasis and NF-κB signaling.

Cancer cells have an efficient antioxidant system to counteract their increased generation of ROS. However, whether this ability to survive high levels of ROS has an important role in the growth and metastasis of tumors is not well understood. Here, we demonstrate that the redox protein thioredoxin-like 2 (TXNL2) regulates the growth and metastasis of human breast cancer cells through a redox signaling mechanism. TXNL2 was found to be overexpressed in human cancers, including breast cancers. Knockdown of TXNL2 in human breast cancer cell lines increased ROS levels and reduced NF-κB activity, resulting in inhibition of in vitro proliferation, survival, and invasion. In addition, TXNL2 knockdown inhibited tumorigenesis and metastasis of these cells upon transplantation into immunodeficient mice. Furthermore, analysis of primary breast cancer samples demonstrated that enhanced TXNL2 expression correlated with metastasis to the lung and brain and with decreased overall patient survival. Our studies provided insight into redox-based mechanisms underlying tumor growth and metastasis and suggest that TXNL2 could be a target for treatment of breast cancer.

FOXC1 is a potential prognostic biomarker with functional significance in basal-like breast cancer.

Gene expression signatures for a basal-like breast cancer (BLBC) subtype have been associated with poor clinical outcomes, but a molecular basis for this disease remains unclear. Here, we report overexpression of the transcription factor FOXC1 as a consistent feature of BLBC compared with other molecular subtypes of breast cancer. Elevated FOXC1 expression predicted poor overall survival in BLBC (P = 0.0001), independently of other clinicopathologic prognostic factors including lymph node status, along with a higher incidence of brain metastasis (P = 0.02) and a shorter brain metastasis-free survival in lymph node-negative patients (P < 0.0001). Ectopic overexpression of FOXC1 in breast cancer cells increased cell proliferation, migration, and invasion, whereas shRNA-mediated FOXC1 knockdown yielded opposite effects. Our findings identify FOXC1 as a theranostic biomarker that is specific for BLBC, offering not only a potential prognostic candidate but also a potential molecular therapeutic target in this breast cancer subtype.