Prognostic impact of fatty acid synthase expression in upper urinary tract urothelial carcinoma

Expressions of P-Glycoprotein, Multidrug Resistance Protein 1 and Annexin A2 as Predictive Factors for Intravesical Recurrence of Bladder Cancer after the Initial Transurethral Resection and Immediate Single Intravesical Instillation of Adriamycin

OBJECTIVE

Immediate single instillation of chemotherapy following transurethral resection of bladder tumor (TURBT) is suggested for non-muscle invasive bladder cancer (NMIBC) patients. However, no study has evaluated molecular marker that was involved in intravesical recurrence (IVR) after single instillation of chemotherapy. Therefore, this study aimed to evaluate whether P-glycoprotein, multidrug resistance protein 1 (MRP1), Annexin A2 (ANXA2) or nucleophosmin (NPM) expression predicts IVR after initial TURBT and immediate single intravesical adriamycin instillation.

METHODS

We retrospectively reviewed consecutive 443 patients who underwent TURBT. Of these, 54 patients who underwent initial TURBT and single instillation of adriamycin for NMIBC were included. The expressions of P-glycoprotein, MRP1, ANXA2 and NPM were evaluated immunohistochemically and were divided into 2 groups (low or high) according to the staining intensity and/or proportion of positive cells. IVR was assessed by Kaplan-Meier method. Cox`s multivaritate analyses were performed to identify independent predictors for IVR.

RESULTS

Nineteen patients (35.1%) had IVR. High P-glycoprotein expression was significantly correlated with multiplicity, pT stage and high grade. High ANXA2 expression was significantly correlated with high grade. MRP1 and NPM were not correlated with any clinicopathological variables. MRP1 expression and ANXA2 expression were significantly correlated with P-glycoprotein expression. Patients with high P-glycoprotein expression had significantly worse IVR-free survival (IVRFS) than those with low P-glycoprotein expression (P =0.015). The difference in IVRFS rates between patients with high ANXA2 expression and those with low ANXA2 expression was nearly significant (P =0.057). Univariate analyses indicated multiplicity, high grade and high P-glycoprotein expression were significant predictors for IVR. Multivariate analysis indicated high grade was an independent predictor for IVR.

CONCLUSIONS

High P-glycoprotein expression was associated with IVR. Further study was needed to determine significance of P-glycoprotein expression in IVR after single intravesical adriamycin instillation.

Effect of increased expression of both ras-related C3 botulinum toxin substrate 1 and p21-activated kinase 1 in patients with N0M0 upper urinary tract urothelial carcinoma and cancer-free surgical margins

BACKGROUND

As a member of the Rho small guanosine triphosphatase family, ras-related C3 botulinum toxin substrate 1 (RAC1) interacts with various specific effectors, and p21-activated kinase 1 (PAK1), which has a role in both carcinogenesis and cellular invasion, binds to RAC1, after which activated PAK1 regulates cellular functions. There have been few reports about the simultaneous analysis of RAC1 and its downstream effector PAK1 in upper urinary tract urothelial carcinoma (UTUC). We assessed the expressions of both RAC1 and PAK1 and evaluated their association with clinicopathological parameters.

METHODS

Immunohistochemical studies of RAC1 or PAK1 were performed with specimens from 104 patients with N0M0 UTUC and cancer-free surgical margins. Correlation of the positive expression of RAC1 or PAK1 or both with clinicopathological parameters was evaluated.

RESULTS

A hazard model showed that the presence of mixed histologic features and moderate or strong positive expression of both RAC1 and PAK1 were independent factors for shortened disease-specific survival time (Ps = 0.041 and 0.016, respectively), and another hazard model revealed that only moderate or strong positive expression of both RAC1 and PAK1 was an independent factor for shortened recurrence-free survival time in the multivariate analysis (P = 0.036). Neither moderate or strong positive expression of RAC1 alone nor moderate or strong positive expression of PAK1 alone was an independent factor for a worse rate of disease-specific or recurrence-free survival in multivariate analysis.

CONCLUSIONS

Patients with N0M0 UTUC, cancer-free surgical margins and moderate or strong positive expression of both RAC1 and PAK1 should be carefully monitored after surgery.

Interethnic differences in the impact of body mass index on upper tract urothelial carcinoma following radical nephroureterectomy

PURPOSE

Inconsistent prognostic implications of body mass index (BMI) in upper tract urothelial carcinoma (UTUC) have been reported across different ethnicities. In this study, we aimed to analyze the oncologic role of BMI in Asian and Caucasian patients with UTUC.

METHODS

We retrospectively collected data from 648 Asian Taiwanese and 213 Caucasian American patients who underwent radical nephroureterectomy for UTUC. We compared clinicopathologic features among groups categorized by different BMI. Kaplan-Meier method and Cox regression model were used to examine the impact of BMI on recurrence and survival by ethnicity.

RESULTS

According to ethnicity-specific criteria, overweight and obesity were found in 151 (23.2%) and 215 (33.2%) Asians, and 79 (37.1%) and 78 (36.6%) Caucasians, respectively. No significant association between BMI and disease characteristics was detected in both ethnicities. On multivariate analysis, overweight and obese Asians had significantly lower recurrence than those with normal weight (HR 0.631, 95% CI 0.413-0.966; HR 0.695, 95% CI 0.493-0.981, respectively), and obesity was an independent prognostic factor for favorable cancer-specific and overall survival (HR 0.521, 95% CI 0.342-0.794; HR 0.545, 95% CI 0.386-0.769, respectively). There was no significant difference in outcomes among normal, overweight and obese Caucasians, but obese patients had a relatively poorer 5-year RFS, CSS, and OS rates of 52.8%, 60.5%, and 47.2%, compared to 54.9%, 69.1%, and 54.9% for normal weight patients.

CONCLUSION

Higher BMI was associated with improved outcomes in Asian patients with UTUC. Interethnic differences could influence preoperative counseling or prediction modeling in patients with UTUC.

Orlistat as a FASN inhibitor and multitargeted agent for cancer therapy

INTRODUCTION

Cancer cells have increased glycolysis and glutaminolysis. Their third feature is increased de novo lipogenesis. As such, fatty acid (FA) synthesis enzymes are over-expressed in cancer and their depletion causes antitumor effects. As fatty acid synthase (FASN) plays a pivotal role in this process, it is an attractive target for cancer therapy.

AREAS COVERED

This is a review of the lipogenic phenotype of cancer and how this phenomenon can be exploited for cancer therapy using inhibitors of FASN, with particular emphasis on orlistat as a repurposing drug.

EXPERT OPINION

Disease stabilization only has been observed with a highly selective FASN inhibitor used as a single agent in clinical trials. It is too early to say whether the absence of tumor responses other than stabilization results because even full inhibition of FASN is not enough to elicit antitumor responses. The FASN inhibitor orlistat is a 'dirty' drug with target-off actions upon at least seven targets with a proven role in tumor biology. The development of orlistat formulations suited for its intravenous administration is a step ahead to shed light on the concept that drug promiscuity can or not be a virtue.

Fatty acid synthase inhibits the O-GlcNAcase during oxidative stress

The dynamic post-translational modification O-linked β-N-acetylglucosamine (O-GlcNAc) regulates thousands of nuclear, cytoplasmic, and mitochondrial proteins. Cellular stress, including oxidative stress, results in increased O-GlcNAcylation of numerous proteins, and this increase is thought to promote cell survival. The mechanisms by which the O-GlcNAc transferase (OGT) and the O-GlcNAcase (OGA), the enzymes that add and remove O-GlcNAc, respectively, are regulated during oxidative stress to alter O-GlcNAcylation are not fully characterized. Here, we demonstrate that oxidative stress leads to elevated O-GlcNAc levels in U2OS cells but has little impact on the activity of OGT. In contrast, the expression and activity of OGA are enhanced. We hypothesized that this seeming paradox could be explained by proteins that bind to and control the local activity or substrate targeting of OGA, thereby resulting in the observed stress-induced elevations of O-GlcNAc. To identify potential protein partners, we utilized BioID proximity biotinylation in combination with stable isotopic labeling of amino acids in cell culture (SILAC). This analysis revealed 90 OGA-interacting partners, many of which exhibited increased binding to OGA upon stress. The associations of OGA with fatty acid synthase (FAS), filamin-A, heat shock cognate 70-kDa protein, and OGT were confirmed by co-immunoprecipitation. The pool of OGA bound to FAS demonstrated a substantial (∼85%) reduction in specific activity, suggesting that FAS inhibits OGA. Consistent with this observation, FAS overexpression augmented stress-induced O-GlcNAcylation. Although the mechanism by which FAS sequesters OGA remains unknown, these data suggest that FAS fine-tunes the cell's response to stress and injury by remodeling cellular O-GlcNAcylation.

Increased nucleophosmin expression is a strong predictor of recurrence and prognosis in patients with N0M0 upper tract urothelial carcinoma undergoing radical nephroureterectomy

PURPOSE

We aimed to evaluate whether increased nucleophosmin expression predicts recurrence and survival in upper tract urothelial carcinoma (UTUC).

METHODS

Specimens from 101 patients with N0M0 UTUC undergoing radical nephroureterectomy were evaluated. Nucleophosmin expression was determined immunohistochemically and categorized into two groups according to nucleophosmin staining intensity. The association between nucleophosmin expression and various clinicopathological factors including Ki-67 expression was analyzed. Multivariate analyses were performed to identify the independent predictors of extraurothelial recurrence and cancer-specific survival.

RESULTS

High nucleophosmin expression was significantly correlated with tumor location, pT ≥3, lymphovascular invasion, lymph node metastasis, and high Ki-67 expression. Patients whose tumors demonstrated high nucleophosmin expression had a significantly higher rate of extraurothelial recurrence and a lower survival rate than those with low nucleophosmin expression. Multivariate analysis showed that pT ≥3, lymph node metastasis, high nucleophosmin expression, and high Ki-67 expression were independent predictors of extraurothelial recurrence. When patients were stratified into three groups according to the number of risk factors, the 2-year extraurothelial recurrence-free survival rates were 92.9% in patients with 0 or 1 risk factor, 76.5% in patients with 2 risk factors, and 9.1% in patients with 3 or 4 risk factors. Regarding cancer-specific survival, lymphovascular invasion and high nucleophosmin expression were independent predictors.

CONCLUSIONS

Increased nucleophosmin expression was a strong predictor of extraurothelial recurrence and cancer-specific survival in patients with N0M0 UTUC undergoing radical nephroureterectomy. Our risk stratification models integrating nucleophosmin expression may provide valuable information on disease recurrence and prognosis.

Molecular targets of luteolin in cancer

Many food-derived phytochemical compounds and their derivatives represent a cornucopia of new anticancer compounds. Despite extensive study of luteolin, the literature has no information on the exact mechanisms or molecular targets through which it deters cancer progression. This review discusses existing data on luteolin's anticancer activities and then offers possible explanations for and molecular targets of its cancer-preventive action. Luteolin prevents tumor development largely by inactivating several signals and transcription pathways essential for cancer cells. This review also offers insights into the molecular mechanisms and targets through which luteolin either prevents cancer or mediates cancer cell death.

Overexpression of fatty acid synthase predicts a poor prognosis for human gastric cancer

Fatty acid synthase (FASN), a lipogenic multi-enzyme complex, is reported to be overexpressed in various types of of tumor tissues and serves an important role in tumor development and progression. However, the expression of FASN and its possible role in gastric cancer (GC) remains to be defined. In the present study, FASN expression in a group sample of 167 GC tissues was detected by immunohistochemistry and its correlation with clinicopathological features was analyzed. By clinical analysis, it was identified that FASN overexpression was positively correlated with the overall survival [P=0.008; hazard ratio (HR), 4.412; 95% confidence interval (CI), 1.463‑13.305] and recurrence rate (P=0.014; HR, 1.705; 95% CI, 1.116‑2.606) in patients with GC. In addition, expression of the FASN protein in GC tissues was correlated with age (P=0.032), clinical stage (P<0.001), gastric wall invasion (P=0.014), lymph node metastasis (P<0.001) and distant metastasis (P<0.001), however not with gender (P>0.05). In addition, FASN was observed to be overexpressed in GC tissues at an mRNA and protein level, compared with the adjacent non-cancerous tissues (P<0.05). Taken together, it was suggested that FASN was closely associated with GC metastasis and survival, which further provided evidence that FASN may be a promising prognostic biomarker for patients with GC.

Integrative Protein-Based Prognostic Model for Early-Stage Endometrioid Endometrial Cancer

PURPOSE

Endometrioid endometrial carcinoma (EEC) is the major histologic type of endometrial cancer, the most prevalent gynecologic malignancy in the United States. EEC recurrence or metastasis is associated with a poor prognosis. Early-stage EEC is generally curable, but a subset has high risk of recurrence or metastasis. Prognosis estimation for early-stage EEC mainly relies on clinicopathologic characteristics, but is unreliable. We aimed to identify patients with high-risk early-stage EEC who are most likely to benefit from more extensive surgery and adjuvant therapy by building a prognostic model that integrates clinical variables and protein markers.

EXPERIMENTAL DESIGN

We used two large, independent early-stage EEC datasets as training (n = 183) and validation cohorts (n = 333), and generated the levels of 186 proteins and phosphoproteins using reverse-phase protein arrays. By applying an initial filtering and the elastic net to the training samples, we developed a prognostic model for overall survival containing two clinical variables and 18 protein markers and optimized the risk group classification.

RESULTS

The Kaplan-Meier survival analyses in the validation cohort confirmed an improved discriminating power of our prognostic model for patients with early-stage EEC over key clinical variables (log-rank test, P = 0.565 for disease stage, 0.567 for tumor grade, and 1.3 × 10(-4) for the integrative model). Compared with clinical variables (stage, grade, and patient age), only the risk groups defined by the integrative model were consistently significant in both univariate and multivariate analyses across both cohorts.

CONCLUSIONS

Our prognostic model is potentially of high clinical value for stratifying patients with early-stage EEC and improving their treatment strategies.

PPARα inhibition modulates multiple reprogrammed metabolic pathways in kidney cancer and attenuates tumor growth

Kidney cancer [renal cell carcinoma (RCC)] is the sixth-most-common cancer in the United States, and its incidence is increasing. The current progression-free survival for patients with advanced RCC rarely extends beyond 1-2 yr due to the development of therapeutic resistance. We previously identified peroxisome proliferator-activating receptor-α (PPARα) as a potential therapeutic target for this disease and showed that a specific PPARα antagonist, GW6471, induced apoptosis and cell cycle arrest at G0/G1 in RCC cell lines associated with attenuation of cell cycle regulatory proteins. We now extend that work and show that PPARα inhibition attenuates components of RCC metabolic reprogramming, capitalizing on the Warburg effect. The specific PPARα inhibitor GW6471, as well as a siRNA specific to PPARα, attenuates the enhanced fatty acid oxidation and oxidative phosphorylation associated with glycolysis inhibition, and PPARα antagonism also blocks the enhanced glycolysis that has been observed in RCC cells; this effect did not occur in normal human kidney epithelial cells. Such cell type-specific inhibition of glycolysis corresponds with changes in protein levels of the oncogene c-Myc and has promising clinical implications. Furthermore, we show that treatment with GW6471 results in RCC tumor growth attenuation in a xenograft mouse model, with minimal obvious toxicity, a finding associated with the expected on-target effects on c-Myc. These studies demonstrate that several pivotal cancer-relevant metabolic pathways are inhibited by PPARα antagonism. Our data support the concept that targeting PPARα, with or without concurrent inhibition of glycolysis, is a potential novel and effective therapeutic approach for RCC that targets metabolic reprogramming in this tumor.