Role of Surgery in locally advanced prostate cancer

Survival and prognostic determinants of prostate cancer patients in Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia: A retrospective cohort study

Background

Globally, the incidence of prostate cancer is increasing, particularly in low- and middle-income countries. It is the most common cancer among men worldwide, with higher mortality in low and middle-income countries. In Ethiopia, it is the second most common cause of cancer morbidity and mortality among men. Despite a few studies done regarding the disease burden, the evidence is scarce about the survival and prognostic determinants of prostate cancer patients in Ethiopia. Thus, this study assessed the survival and prognostic determinants of patients with prostate cancer.

Methods

We retrospectively followed patients who were newly diagnosed from 2012 to 2016 at the Oncology Department of Tikur Anbessa Specialized Hospital. We extracted the data from patient charts that were available in the cancer registry using a checklist with the help of oncology nurses. Kaplan-Meier survival analyses with the log-rank test were used to estimate and compare the probability of survival among covariate categories. After checking for assumptions, a multivariable Cox regression analysis was performed to identify prognostic determinants of survival.

Results

The median survival time was 28 months with an overall 2-, 3- and 5-year survival of 57%, 38.9% and 22%, respectively. The overall survival differs according to the clinical stage (P-value<0.01), presence or absence of distant metastasis (P<0.01) and androgen deprivation therapy (ADT) (P<0.05). Cancer stage at diagnosis (adjusted hazard ratio (AHR) = 0.309, 95%CI = 0.151–0.633) and ADT (AHR = 3.884, 95%CI = 1.677–8.997) remained significant in the final Cox proportional hazards model.

Conclusions

The overall 2-, 3- and 5-year survival of prostate cancer patients in Ethiopia is very low. The cancer stage at diagnosis and treatment modalities are significant prognostic determinants of survival. Therefore, early detection through screening and timely initiation of treatment are essential to improve the survival of prostate cancer patients.

The role of cystoprostatectomy in management of locally advanced prostate cancer: a systematic review

Background

The role of cystoprostatectomy for the treatment of locally advanced prostate cancer (LAPC) was evaluated by a comprehensive review of contemporary literatures.

Methods

A systematic search of English language literatures using PubMed, EMBASE, Web of Science, and Cochrane library, from 1990 to 2018, was performed. Two independent authors reviewed abstracts as well as full-text articles and extracted data from the selected manuscripts.

Results

After the literature research, seven articles with a total of 211 patients were identified. Both 120 cases who received cystoprostatectomy for the primary treatment of LAPC and 91 cases for the salvage surgery after local recurrence were finally included. Overall incidence of positive surgical margins ranged from 25 to 78%. The incidence of major complications caused by the surgery during the follow-up time was limited. It had been reported that among LAPC patients who received cystoprostatectomy combined with adjuvant therapies, 5-year cancer-specific survival rate and 5-year biochemical progression-free survival was up to 87.1% and 62.2%. Moreover, symptoms such as hematuria and other urination dysfunctions, as well as patients’ quality of life were significantly improved after cystoprostatectomy in LAPC patients with the bladder invasion.

Conclusions

Cystoprostatectomy can serve as an alternative to the surgical step of multimodal therapy for highly selected LAPC patients with the bladder invasion, which may improve patients’ symptoms and related quality of life. Therefore, cystoprostatectomy as an option for the treatment of LAPC with the bladder invasion may be feasible and safe with considerable survival outcomes.

miR-615 Inhibits Prostate Cancer Cell Proliferation and Invasion by Directly Targeting Cyclin D2

Previous studies have reported that miR-615 exerts a tumor suppressor role in some tumors, such as esophageal squamous cell carcinoma and non-small cell lung cancer. However, the role of miR-615 in prostate cancer has not been defined. Here we found that miR-615 was downregulated in prostate cancer tissues and cell lines. Overexpression of miR-615 in PC-3 cells significantly inhibited cellular proliferation, migration, and invasion. Moreover, overexpression of miR-615 delayed tumor growth in vivo. In terms of mechanism, we found that cyclin D2 (CCND2) is a target gene of miR-615 in prostate cancer. We showed that miR-615 could bind to the 3′-UTR region of CCND2 mRNA and inhibit its expression. There was a negative correlation between the expression of miR-615 and CCND2 in prostate cancer tissues. Moreover, restoration of cyclin D2 abolished the inhibitory effects of miR-615 on the proliferation, migration, and invasion of prostate cancer cells. Taken together, our study identified miR-615 as a tumor suppressor by targeting cyclin D2 in prostate cancer.

miR-20b promotes cellular proliferation and migration by directly regulating phosphatase and tensin homolog in prostate cancer

MicroRNAs are small non-coding RNAs, which are critical regulators of carcinogenesis and tumor progression. Previous studies have identified that microRNA-20b (miR-20b) acts as an oncogene in numerous cancers. However, the role of miR-20b in prostate cancer remains unclear. The present study aimed to investigate the expression of miR-20b in prostate cancer and to examine whether modulating miR-20b expression impacts prostate cancer cellular proliferation and migration. It was revealed that miR-20b was strongly expressed in prostate cancer tissues compared with adjacent normal prostate tissues (P<0.05). Knockdown of miR-20b expression by miR-20b inhibitor inhibited VCaP and PC-3 cell growth and migration. Through bioinformatics analysis, phosphatase and tensin homolog (PTEN) was predicted as a target gene of miR-20b in prostate cancer cells, which was validated by dual-luciferase reporter assay and western blot analysis. In addition, restoration of PTEN expression levels did not affect endogenous miR-20b expression in prostate cancer cells. In conclusion, the present study indicated that miR-20b promotes cellular proliferation and migration by directly regulating PTEN in prostate cancer.

MicroRNA-125a-5p regulates cancer cell proliferation and migration through NAIF1 in prostate carcinoma

Background

We investigated the functional roles of microRNA-125a-5p in regulating human prostate carcinoma.

Methods

Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was conducted to evaluate the gene expression levels of miR-125a-5p in eight prostate cancer cell lines and nine biopsy specimens from patients with prostate cancer. miR-125a-5p was genetically knocked down in prostate cancer cell lines, DU145 and VCaP cells by lentiviral transduction. The effects of miR-125a-5p downregulation on prostate cancer cell proliferation and migration were evaluated by MTT assay and transwell assay, respectively. Direct regulation of miR-125a-5p on its downstream targets, NAIF1, and apoptotic gene caspase-3 were evaluated through dual-luciferase reporter assay, qRT-PCR, and Western blot, respectively. NAIF1 was then ectopically overexpressed in DU145 and VCaP cells to modulate prostate cancer cell proliferation and migration. Finally, the effects of miR-125a-5p downregulation or NAIF1 overexpression on the growth of in vivo prostate cancer xenograft were evaluated.

Results

miR-125a-5p was upregulated in prostate cancer cell lines and human prostate carcinomas. Lentivirus induced miR-125a-5p downregulation in DU145 and VCaP cells inhibited prostate cancer cell proliferation or migration. NAIF1 was the direct target of miR-125a-5p, as both gene and protein expression levels of NAIF1, as well as caspase-3 were upregulated by miR-125a-5p. Forced overexpression of NAIF1 had similar antitumor effects as miR-125a-5p downregulation on prostate cancer cell proliferation and migration. In vivo prostate xenograft assay confirmed the tumor-suppressive effect of miR-125a-5p downregulation or NAIF1 overexpression.

Conclusion

miR-125a-5p regulates prostate cancer cell proliferation and migration through NAIF1.

Identification of Novel Epigenetic Markers of Prostate Cancer by NotI-Microarray Analysis

A significant need for reliable and accurate cancer diagnostics and prognosis compels the search for novel biomarkers that would be able to discriminate between indolent and aggressive tumors at the early stages of disease. The aim of this work was identification of potential diagnostic biomarkers for characterization of different types of prostate tumors. NotI-microarrays with 180 clones associated with chromosome 3 genes/loci were applied to determine genetic and epigenetic alterations in 33 prostate tumors. For 88 clones, aberrations were detected in more than 10% of tumors. The major types of alterations were DNA methylation and/or deletions. Frequent methylation of the discovered loci was confirmed by bisulfite sequencing on selective sampling of genes: FGF12, GATA2, and LMCD1. Three genes (BHLHE40, BCL6, and ITGA9) were tested for expression level alterations using qPCR, and downregulation associated with hypermethylation was shown in the majority of tumors. Based on these data, we proposed the set of potential biomarkers for detection of prostate cancer and discrimination between prostate tumors with different malignancy and aggressiveness: BHLHE40, FOXP1, LOC285205, ITGA9, CTDSPL, FGF12, LOC440944/SETD5, VHL, CLCN2, OSBPL10/ZNF860, LMCD1, FAM19A4, CAND2, MAP4, KY, and LRRC58. Moreover, we probabilistically estimated putative functional relations between the genes within each set using the network enrichment analysis.