Preoperative prostate health index predicts poor pathologic outcomes of radical prostatectomy in patients with biopsy-detected low-risk patients prostate cancer: results from a Chinese prospective cohort.

OBJECTIVE: To determine the performance of the prostate health index (PHI) in predicting pathologic outcomes of radical prostatectomy (RP) in Chinese patients with low-risk prostate cancer (PCa). METHODS: Of all consecutive patients who underwent RP in one tertiary center from September 2013 to January 2017, we prospectively examined the data of 140 patients with low-risk PCa based on the Prostate Cancer Research International: Active Surveillance (PRIAS) criteria. All patients were eligible for active surveillance, but underwent RP. Clinical and pathological data were collected. Logistic regression was used to evaluate the associations between the PHI and outcome of RP. The area under the receiver operating curve (AUC) was used to evaluate the accuracy of different models. Decision curve analysis was used to evaluate the potential clinical usefulness of making model-based decisions. RESULTS: Only 44 (31.4%) patients were finally confirmed to have organ-confined Gleason ≤6 PCa. A low PHI was significantly predictive of organ-confined Gleason ≤6 PCa (p = 0.001), while tPSA and f/tPSA were not associated with final pathology. In the multivariate analyses, addition of the PHI significantly increased the predictive accuracy (AUC = 0.767, 95% Cl 0.685-0.849, p < 0.001). CONCLUSION: The PRIAS criteria for active surveillance may not suitable for Chinese patients with PCa. Addition of the PHI to the PRIAS models improved the prognostic performance. If confirmed in future larger and multicenter studies, PHI may help us to identify patients eligible for AS in China.

Smoking increased the risk of prostate cancer with grade group ≥ 4 and intraductal carcinoma in a prospective biopsy cohort.

OBJECTIVE: To investigate the association between smoking and different prostate cancer (PCa) pathological subtypes incidence in Chinese men. PATIENTS AND METHODS: We prospectively included 1795 patients who underwent prostate biopsies in one tertiary center between March 2013 and April 2016. Clinical data and biopsy outcomes were collected. Logistic regression was used to evaluate the association between cigarette smoking and PCa incidence. RESULTS: A total of 737 men, 480 men and 58 men were diagnosed with PCa, high-grade PCa (HGPCa, grade group ≥ 4 as accepted by the 2014 ISUP) and intraductal carcinoma of the prostate (IDC-P), respectively. Current smokers had a significantly higher risk of HGPCa than never smokers (OR = 1.89, 95%CI: 1.44-2.48). No such association was observed for low-grade disease and cigarette smoking (OR = 0.84, 95%CI: 0.61-1.16). In a sub-analysis, men who had smoked longer than 30 years had a higher risk of HGPCa, compared with men who had smoked fewer than 30 years (OR = 1.50, 95%CI: 1.09-2.06). Current smokers were more likely to develop IDC-P than never smokers (OR = 2.29, 95%CI: 1.14-4.59). CONCLUSION: Among men in this Chinese biopsy cohort, current smoking was associated with highly malignant PCa incidence, such as HGPCa and IDC-P. The duration of smoking may be associated with HGPCa.

Waist-hip Ratio (WHR), a Better Predictor for Prostate Cancer than Body Mass Index (BMI): Results from a Chinese Hospital-based Biopsy Cohort.

To investigate whether waist-hip ratio (WHR) is a better predictor of prostate cancer (PCa) incidence than body mass index (BMI) in Chinese men. Of consecutive patients who underwent prostate biopsies in one tertiary center between 2013 and 2015, we examined data on 1018 with PSA ≤20 ng/ml. Clinical data and biopsy outcomes were collected. Logistic regression was used to evaluate the associations between BMI, WHR and PCa incidence. Area under the ROC (AUC) was used to evaluate the accuracy of different prognostic models. A total of 255 men and 103 men were diagnosed with PCa and high grade PCa (HGPCa, Gleason score ≥8). WHR was an independent risk factor for both PCa (OR = 1.07 95%Cl 1.03-1.11) and HGPCa (OR = 1.14 95%Cl 1.09-1.19) detection, while BMI had no relationship with either PCa or HGPCa detection. Adding WHR to a multivariable model increased the AUC for detecting HGPCa from 0.66 (95%Cl 0.60-0.72) to 0.71 (95%Cl 0.65-0.76). In this Chinese cohort, WHR was significantly predictive of PCa and HGPCa. Adding WHR to a multivariable model increased the diagnostic accuracy for detecting HGPCa. If confirmed, including WHR measurement may improve PCa and HGPCa detection.

Parthenolide induces autophagy via the depletion of 4E-BP1.

Parthenolide (PTL) is a sesquiterpene lactone isolated from feverfew and exhibits potent antitumor activity against various cancers. Many studies indicate that PTL treatment leads to apoptosis, however, the mechanism has not been defined. Here, we observed that cells underwent autophagy shortly after PTL treatment. Inhibition of autophagy by knocking out autophagy associated gene atg5 blocked PTL-induced apoptosis. Surprisingly, PTL decreased the level of translation initiation factor eIF4E binding protein 1 (4E-BP1) in correlation with autophagy. Ectopic expression or shRNA knockdown of 4E-BP1 further verified the effect of 4E-BP1 on PTL-induced autophagy. Meanwhile, PTL elevated the cellular reactive oxygen species (ROS) which located upstream of the depletion of 4E-BP1, and contributed to the consequent autophagy. This study revealed 4E-BP1 as a trigger for PTL-induced autophagy and may lead to therapeutic strategy to enhance the efficacy of anticancer drugs.

Estrogen induces Vav1 expression in human breast cancer cells.

Vav1, a guanine nucleotide exchange factor (GEF) for Rho family GTPases, is a hematopoietic protein involved in a variety of cellular events. In recent years, aberrant expression of Vav1 has been reported in non-hematopoietic cancers including human breast cancer. It remains to be answered how Vav1 is expressed and what Vav1 does in its non-resident tissues. In this study, we aimed to explore the mechanism for Vav1 expression in breast cancer cells in correlation with estrogen-ER pathway. We not only verified the ectopic expression of Vav1 in human breast cancer cell lines, but also observed that Vav1 expression was induced by 17ß-estradiol (E2), a typical estrogen receptor (ER) ligand, in ER-positive cell lines. On the other hand, Tamoxifen, a selective estrogen receptor modulator (SERM), and ICI 182,780, an ER antagonist, suppressed the expression of Vav1. The estrogen receptor modulating Vav1 expression was identified to be α form, not ß. Furthermore, treatment of E2 increased the transcription of vav1 gene by enhancing the promoter activity, though there was no recognizable estrogen response element (ERE). Nevertheless, two regions at the vav1 gene promoter were defined to be responsible for E2-induced activation of vav1 promoter. Chromatin immunoprecipitation (ChIP) and co-immunoprecipitation (Co-IP) analyses suggested that ERα might access to the vav1 promoter via interacting with transcription factors, c-Myb and ELF-1. Consequently, the enhanced expression of Vav1 led to the elevation of Cyclin D1 and the progression of cell cycle. The present study implies that estrogen-ER modulates the transcription and expression of Vav1, which may contribute to the proliferation of cancerous cells.

Vav1 increases Bcl-2 expression by selective activation of Rac2-Akt in leukemia T cells.

Vav proteins are guanine nucleotide exchange factors (GEFs) that activate a group of small G proteins (GTPases). Vav1 is predominantly expressed in hematopoietic cells, whereas Vav2 and Vav3 are ubiquitously distributed in almost all human tissues. All three Vav proteins contain conserved structural motifs and associate with a variety of cellular activities including proliferation, migration, and survival. Previous observation with Jurkat leukemia T cells showed that Vav1 possessed anti-apoptotic activity by enhancing Bcl-2 transcription. However the mechanism has not been unveiled. Here, we explored the effectors of Vav1 in promoting Bcl-2 expression in Jurkat cells and revealed that Rac2-Akt was specifically evoked by the expression of Vav1, but not Vav2 or Vav3. Although all three Vav isoforms existed in Jurkat cells, Rac2 was distinguishably activated by Vav1 and that led to enhanced Bcl-2 expression and cell survival. Akt was modulated downstream of Vav1-Rac2, and the activation of Akt was indispensable in the enhanced transcription of Bcl-2. Intriguingly, neither Vav2 nor Vav3 was able to activate Rac2-Akt pathway as determined by gene silencing approach. Our data illustrated a unique role of Vav1 in T leukemia survival by selectively triggering Rac2-Akt axis and elevating the expression of anti-apoptotic Bcl-2.

The N-terminal 20-amino acid region of guanine nucleotide exchange factor Vav1 plays a distinguished role in T cell receptor-mediated calcium signaling.

Vav1 is a guanine nucleotide exchange factor (GEF) specifically expressed in hematopoietic cells. It consists of multiple structural domains and plays important roles in T cell activation. The other highly conserved isoforms of Vav family, Vav2 and Vav3, are ubiquitously expressed in human tissues including lymphocytes. All three Vav proteins activate Rho family small GTPases, which are involved in a variety of biological processes during T cell activation. Intensive studies have demonstrated that Vav1 is indispensable for T cell receptor (TCR)-mediated signal transduction, whereas Vav2 and Vav3 function as GEFs that overlap with Vav1 on TCR-induced cytoskeleton reorganization. T cells lacking Vav1 exhibited severe defect in TCR-mediated calcium elevation, indicating that the co-existing Vav2 and Vav3 did not compensate Vav1 in calcium signaling. What is the functional particularity of Vav1 in lymphocytes? In this study, we identified the N-terminal 20 amino acids of Vav1 in the calponin homology (CH) domain to be essential for its interaction with calmodulin (CaM) that leads to TCR-induced calcium mobilization. Substitution of the 1-20 amino acids of Vav1 with those of Vav2 or Vav3 abolished the association with CaM, and the N-terminal mutations of Vav1 failed to potentiate normal TCR-induced calcium mobilization, that in turn, suspended nuclear factor of activated T cells (NFAT) activation and IL-2 production. This study highlights the importance of the N-terminal 20 aa of Vav1 for CaM binding, and provides new insights into the distinguished and irreplaceable role of Vav1 in T cell activation and signal transduction.

The distinct role of guanine nucleotide exchange factor Vav1 in Bcl-2 transcription and apoptosis inhibition in Jurkat leukemia T cells.

AIM: To investigate a novel function of proto-oncogene Vav1 in the apoptosis of human leukemia Jurkat cells. METHODS: Jurkat cells, Jurkat-derived vav1-null cells (J.Vav1) and Vav1-reconstituted J.WT cells were treated with a Fas agonist antibody, IgM clone CH11. Apoptosis was determined using propidium iodide (PI) staining, Annexin-V staining, DNA fragmentation, cleavage of caspase 3/caspase 8, and poly (ADP-ribose) polymerase (PARP). Mitochondria transmembrane potential (ΔΨ(m)) was measured using DiOC(6)(3) staining. Transcription and expression of the Bcl-2 family of proteins were evaluated using semi-quantitative RT-PCR and Western blot, respectively. Bcl-2 promoter activity was analyzed using luciferase reporter assays. RESULTS: Cells lacking Vav1 were more sensitive to Fas-mediated apoptosis than Jurkat and J.WT cells. J.Vav1 cells lost mitochondria transmembrane potential (ΔΨ(m)) more rapidly upon Fas induction. These phenotypes could be rescued by re-expression of Vav1 in J.Vav1 cells. The expression of Vav1 increased the transcription of pro-survival Bcl-2. The guanine nucleotide exchange activity of Vav1 was required for enhancing Bcl-2 promoter activity, and the Vav1 downstream substrate, small GTPase Rac2, was likely involved in the control of Bcl-2 expression. CONCLUSION: Vav1 protects Jurkat cells from Fas-mediated apoptosis by promoting Bcl-2 transcription through its GEF activity.