Yahya Elshimali

Aromatase Expression Predicts Survival in Women with Early-Stage Non-Small Cell Lung Cancer

Estrogen signaling is critical in the progression of tumors that bear estrogen receptors. In most patients with breast cancer, inhibitors that block interactions of estrogen with its receptors or suppress the production of endogenous estrogens are important interventions in the clinic. Recent evidence now suggests that estrogen also contributes to the pathogenesis of non-small cell lung cancer (NSCLC). We used a human lung cancer xenograph model system to analyze the effect of aromatase or estradiol on tumor growth. We further examined the level of protein expression of aromatase in 422 patients with NSCLC using a high-density tissue microarray. Results were confirmed and validated on an independent patient cohort (n = 337). Lower levels of aromatase predicted a greater chance of survival in women 65 years and older. Within this population, the prognostic value of aromatase was greatest in earlier stage lung cancer (stage I/II). In addition, for women with no history of smoking, lower aromatase levels were a strong predictor of survival. Our findings implicate aromatase as an early-stage predictor of survival in some women with NSCLC. We predict that women whose lung cancers have higher levels of aromatase might be good candidates for targeted treatment with aromatase inhibitors.

The Clinical Utilization of Circulating Cell Free DNA (CCFDNA) in Blood of Cancer Patients

Qualitative and quantitative testing of circulating cell free DNA (CCFDNA) can be applied for the management of malignant and benign neoplasms. Detecting circulating DNA in cancer patients may help develop a DNA profile for early stage diagnosis in malignancies. The technical issues of obtaining, using, and analyzing CCFDNA from blood will be discussed.

Higher Levels of GATA3 Predict Better Survival in Women with Breast Cancer

The GATA family members are zinc finger transcription factors involved in cell differentiation and proliferation. GATA3 in particular is necessary for mammary gland maturation, and its loss has been implicated in breast cancer development. Our goal was to validate the ability of GATA3 expression to predict survival in breast cancer patients. Protein expression of GATA3 was analyzed on a high-density tissue microarray consisting of 242 cases of breast cancer. We associated GATA3 expression with patient outcomes and clinicopathologic variables. Expression of GATA3 was significantly increased in breast cancer, in situ lesions, and hyperplastic tissue compared with normal breast tissue. GATA3 expression decreased with increasing tumor grade. Low GATA3 expression was a significant predictor of disease-related death in all patients, as well as in subgroups of estrogen receptor-positive or low-grade patients. In addition, low GATA3 expression correlated with increased tumor size and estrogen and progesterone receptor negativity. GATA3 is an important predictor of disease outcome in breast cancer patients. This finding has been validated in a diverse set of populations. Thus, GATA3 expression has utility as a prognostic indicator in breast cancer.

Frequent loss of estrogen and progesterone receptors in human prostatic tumors determined by quantitative real-time PCR

Relative gene expression of the estrogen receptors (ER)-alpha (NR3A1) and ER-beta (NR3A2) along with progesterone receptors PR-A and PR-B (NR3C3) was determined by quantitative real-time PCR in a previously characterized panel of paired human prostate tumor and surrounding unaffected tissue (Prostate 54:275). In approximately half of these cases, a 10-fold or greater reduction in the relative mRNA levels of ER-beta but not ER-alpha was found in the cancer as compared to normal tissue, which was also observed with unpaired samples. Immunohistochemical staining for ER-beta and ER-alpha closely paralleled mRNA expression patterns for both receptors in paired samples. Reduced relative expressions of PR-B and total PR-A and PR-B isoforms were also observed in prostate tumor as compared to unaffected tissue, implying a potential role of PR in prostate tissue. The relative decrease in ER-beta is greater than that observed in prior studies, suggesting that paired samples more accurately reflect differences within individual cases. These findings favor the concept that ER-beta mediates anti-proliferative signals and its loss in prostatic tumor promotes proliferation of these cells.

Triple Negative Breast Tumors in African-American and Hispanic/Latina Women Are High in CD44+, Low in CD24+, and Have Loss of PTEN

Background African-American women have higher mortality from breast cancer than other ethnic groups. The association between poor survival and differences with tumor phenotypes is not well understood. The purpose of this study is to assess the clinical significance of (1) Stem cell-like markers CD44 and CD24; (2) PI3K/Akt pathway associated targets PTEN, activation of Akt, and FOXO1; and (3) the Insulin-like growth factor-1 (IGF-I) and IGF binding protein-3 (IGFBP3) in different breast cancer subtypes, and compare the differences between African-American and Hispanic/Latina women who have similar social-economic-status. Methods A total of N=318 African-American and Hispanic/Latina women, with clinically-annotated information within the inclusion criteria were included. Formalin fixed paraffin embedded tissues from these patients were tested for the different markers using immunohistochemistry techniques. Kaplan-Meier survival-curves and Cox-regression analyses were used to assess Relative Risk and Disease-Free-Survival (DFS). Results The triple-negative-breast-cancer (TNBC) receptor-subtype was more prevalent among premenopausal women, and the Hormonal Receptor (HR) positive subtype was most common overall. TNBC tumors were more likely to have loss of PTEN, express high Ki67, and have increased CD44+/CD24- expression. TNBC was also associated with higher plasma-IGF-I levels. HR-/HER2+ tumors showed high pAkt, decreased FOXO1, and high CD24+ expression. The loss of PTEN impacted DFS significantly in African Americans, but not in Hispanics/Latinas after adjusted for treatment and other tumor pathological factors. The CD44+/CD24- and CD24+/CD44- phenotypes decreased DFS, but were not independent predictors for DFS. HER2-positive and TNBC type of cancers continued to exhibit significant decrease in DFS after adjusting for the selected biomarkers and treatment. Conclusions TNBC incidence is high among African-American and Hispanic/Latino women residing in South Los Angeles. Our study also shows for the first time that TNBC was significantly associated with PTEN loss, high Ki67 and the CD44+/CD24- phenotype. The loss of PTEN impacts DFS significantly in African Americans.

Elevated MED28 expression predicts poor outcome in women with breast cancer

BackgroundMED28 (also known as EG-1 and magicin) has been implicated in transcriptional control, signal regulation, and cell proliferation. MED28 has also been associated with tumor progression in invitro and in vivo models. Here we examined the association of MED28 expression with human breast cancer progression.MethodsExpression of MED28 protein was determined on a population basis using a high-density tissue microarray consisting of 210 breast cancer patients. The association and validation of MED28 expression with histopathological subtypes, clinicopathological variables, and disease outcome was assessed.ResultsMED28 protein expression levels were increased in ductal carcinoma in situ and invasive ductal carcinoma of the breast compared to non-malignant glandular and ductal epithelium. Moreover, MED28 was a predictor of disease outcome in both univariate and multivariate analyses with higher expression predicting a greater risk of disease-related death.ConclusionsWe have demonstrated that MED28 expression is increased in breast cancer. In addition, although the patient size was limited (88 individuals with survival information) MED28 is a novel and strong independent prognostic indicator of survival for breast cancer.

Slug contributes to cancer progression by direct regulation of ERα signaling pathway

Hormone therapy targeting estrogen receptor α (ERα) is the most effective treatment for breast cancer. However, this treatment eventually fails as the tumor develops resistance. Although reduced expression of ER-α is a known contributing factor to endocrine resistance, the mechanism of ER-α downregulation in endocrine resistance is still not fully understood. The present study shows that Slug has an inverse relationship with ERα in breast and prostate cancer patient samples. Also the inhibition of Slug blocks mammary stem cell activity in primary mammary epithelial cells. We hypothesize that Slug may be a key transcription factor in the regulation of ERα expression. To understand the Slug-ERα signaling pathway, we employed resistant cell line MCF-TAMR (ERα relatively negative) derived from its parental MCF-7 (ERα positive) cell line and assessed changes in cell phenotype, activity and response to therapy. Conversely, we performed knockdown of Slug in the high-Slug expressing cell line MDA-MB-231 and assessed reversal of the mesenchymal phenotype. Microarray analysis showed that Slug is overexpressed in high grade breast and prostate cancer tissues. Additionally, Slug overexpression leads to drug resistance. Furthermore, we demonstrated that Slug binds directly to ERα promoter E-boxes and represses ERα expression. This resulted in decrease in epithelial-to-mesenchymal transition in cancer cells. These findings demonstrate that Slug, by regulation of ERα expression, contributes to tumor progression and could serve as an important target for cancer therapy.

Predicting biochemical recurrence after radical prostatectomy for patients with organ-confined disease using p27 expression☆

OBJECTIVES It is unclear why men who undergo radical prostatectomy (RP) and are found to have pathologically organ-confined disease develop prostate-specific antigen (PSA) recurrences. We previously found that patients with less than 45% of cells in the prostate needle biopsy specimen (PNBx) staining positive for the cell cycle regulator p27 had a significantly increased risk of biochemical recurrence after RP. We sought to determine whether p27 staining in the PNBx specimen might serve as a molecular marker for PSA failure in the subset of patients who develop PSA recurrence despite organ-confined disease at RP. METHODS The PNBx specimens of 161 men treated with RP between 1991 and 2000 were examined for p27 expression using immunohistochemistry. The p27 cutpoint of less than 45% expression was used to define the high and low-risk categories. Patients were separated into two groups for analysis: organ-confined (pT2 and negative surgical margins) and non-organ-confined (pT2 with positive surgical margins, pT3, pT4, or lymph node involvement). The mean and median follow-up for patients with organ-confined and non-organ-confined disease was 47 and 43 months and 42 and 38 months, respectively. Multivariate Cox proportional hazards analysis was used to examine the preoperative clinical variables that were the strongest predictors of biochemical recurrence after RP among each group. RESULTS Among organ-confined patients, p27 expression was the only significant independent predictor of the time to biochemical recurrence after RP (hazard ratio 5.15, 95% confidence interval 1.41 to 18.83, P = 0.013). Among patients with non-organ-confined disease, the percentage of biopsy tissue with cancer, biopsy Gleason score, and PSA level were independent predictors of PSA recurrence. p27 expression was not a significant independent predictor of PSA recurrence among men with non-organ-confined disease. CONCLUSIONS p27 expression in the PNBx was a significant independent predictor of PSA failure for patients with pathologically organ-confined disease, but not for those with non-organ-confined disease. Patients with organ-confined disease but low p27 expression had a greater than fivefold risk of developing PSA recurrence than were men with high p27 expression, suggesting that p27 may be a molecular marker associated with micrometastatic disease at the time of RP.

Rationale and Preclinical Efficacy of a Novel Anti-EMP2 Antibody for the Treatment of Invasive Breast Cancer

Despite significant advances in biology and medicine, the incidence and mortality due to breast cancer worldwide is still unacceptably high. Thus, there is an urgent need to discover new molecular targets. In this article, we show evidence for a novel target in human breast cancer, the tetraspan protein epithelial membrane protein-2 (EMP2). Using tissue tumor arrays, protein expression of EMP2 was measured and found to be minimal in normal mammary tissue, but it was upregulated in 63% of invasive breast cancer tumors and in 73% of triple-negative tumors tested. To test the hypothesis that EMP2 may be a suitable target for therapy, we constructed a fully human immunoglobulin G1 (IgG1) antibody specific for a conserved domain of human and murine EMP2. Treatment of breast cancer cells with the anti-EMP2 IgG1 significantly inhibited EMP2-mediated signaling, blocked FAK/Src signaling, inhibited invasion, and promoted apoptosis in vitro. In both human xenograft and syngeneic metastatic tumor monotherapy models, anti-EMP2 IgG1 retarded tumor growth without detectable systemic toxicity. This antitumor effect was, in part, attributable to a potent antibody-dependent cell-mediated cytotoxicity response as well as direct cytotoxicity induced by the monoclonal antibody. Together, these results identify EMP2 as a novel therapeutic target for invasive breast cancer. Mol Cancer Ther; 13(4); 902–15. ©2014 AACR.

Lactate, a Neglected Factor for Diabetes and Cancer Interaction

Increasing body of evidence suggests that there exists a connection between diabetes and cancer. Nevertheless, to date, the potential reasons for this association are still poorly understood and currently there is no clinical evidence available to direct the proper management of patients presenting with these two diseases concomitantly. Both cancer and diabetes have been associated with abnormal lactate metabolism and high level of lactate production is the key biological property of these diseases. Conversely, high lactate contribute to a higher insulin resistant status and a more malignant phenotype of cancer cells, promoting diabetes and cancer development and progression. In view of associations between diabetes and cancers, the role of high lactate production in diabetes and cancer interaction should not be neglected. Here, we review the available evidence of lactates role in different biological characteristics of diabetes and cancer and interactive relationship between them. Understanding the molecular mechanisms behind metabolic remodeling of diabetes- and cancer-related signaling would endow novel preventive and therapeutic approaches for diabetes and cancer treatment.