Place du test urinaire PCA3 pour le diagnostic du cancer de la prostate

LncRNA HAND2-AS1 promotes liver cancer stem cell self-renewal via BMP signaling

Hepatocellular carcinoma (HCC) is the most prevalent liver cancer, characterized by a high rate of recurrence and heterogeneity. Liver cancer stem cells (CSCs) may well contribute to both of these pathological properties, but the mechanism underlying their self-renewal maintenance is poorly understood. Here, we identified a long noncoding RNA (lncRNA) termed HAND2-AS1 that is highly expressed in liver CSCs. Human HAND2-AS1 and its mouse ortholog lncHand2 display a high level of conservation. HAND2-AS1 is required for the self-renewal maintenance of liver CSCs to initiate HCC development. Mechanistically, HAND2-AS1 recruits the INO80 chromatin-remodeling complex to the promoter of BMPR1A, thereby inducing its expression and leading to the activation of BMP signaling. Importantly, interfering with expression of HAND2-AS1 by antisense oligonucleotides (ASOs) and BMPR1A by siRNAs has synergistic anti-tumorigenic effects on humanized HCC models. Moreover, knockout of lncHand2 or Bmpr1a in mouse hepatocytes impairs BMP signaling and suppresses the initiation of liver cancer. Our findings reveal that HAND2-AS1 promotes the self-renewal of liver CSCs and drives liver oncogenesis, offering a potential new target for HCC therapy.

Current early diagnostic biomarkers of prostate cancer

Prostate cancer (PCa) has become to have the highest incidence and the second mortality rate in western countries, affecting men's health to a large extent. Although prostate-specific antigen (PSA) was discovered to help diagnose the cancer in an early stage for decades, its specificity is relative low, resulting in unnecessary biopsy for healthy people and over-treatment for patients. Thus, it is imperative to identify more and more effective biomarkers for early diagnosis of PCa in order to distinguish patients from healthy populations, which helps guide an early treatment to lower disease-related mortality by noninvasive or minimal invasive approaches. This review generally describes the current early diagnostic biomarkers of PCa in addition to PSA and summarizes the advantages and disadvantages of these biomarkers.

A highly sensitive targeted mass spectrometric assay for quantification of AGR2 protein in human urine and serum

Anterior gradient 2 (AGR2) is a secreted, cancer-associated protein in many types of epithelial cancer cells. We developed a highly sensitive targeted mass spectrometric assay for quantification of AGR2 in urine and serum. Digested peptides from clinical samples were processed by PRISM (high pressure and high resolution separations coupled with intelligent selection and multiplexing), which incorporates high pH reversed-phase liquid chromatography (LC) separations to fractionate and select target fractions for follow-on LC-selected reaction monitoring (LC-SRM) analyses. The PRISM-SRM assay for AGR2 showed a reproducibility of <10% CV and limit of quantification (LOQ) values of ∼130 pg/mL in serum and ∼10 pg per 100 μg of total protein mass in urine, respectively. A good correlation (R(2) = 0.91) was observed for the measurable AGR2 concentrations in urine between SRM and enzyme-linked immunosorbent assay (ELISA). On the basis of an initial cohort of 37 subjects, urinary AGR2/PSA concentration ratios showed a significant difference (P = 0.026) between noncancer and cancer. Large clinical cohort studies are needed for the validation of AGR2 as a useful diagnostic biomarker for prostate cancer. Our work validated the approach of identifying candidate secreted protein biomarkers through genomics and measurement by targeted proteomics, especially for proteins where no immunoassays are available.

[Variation of urinary PCA3 following transrectal ultrasound-guided prostate biopsy]

INTRODUCTION

Serum PSA is known to rise slightly following an attentive digital rectal examination (DRE) and dramatically following prostatic biopsy. The aim of this study was to evaluate the PCA3 response in these situations.

PATIENTS AND METHODS

In 15 consecutive men undergoing transrectal ultrasound-guided needle biopsy of the prostate and who gave their informed consent, urinary PCA3 was determined twice: at a first consultation, urine being sampled immediately after an attentive DRE and second within 2 hours after the biopsy. The mean interval between the two samplings was 14 days (median 15). PCA3 measurements were centralized and performed by the same biologist. At least twelve cores were taken using a biopsy gun with an 18-gauge needle. Changes in PCA3 levels were studied.

RESULTS

Mean age of the 15 men was 67.3 years (range 50.9-79.1). Mean (median) pre-biopsy total and %free PSA were respectively 6.6 ng/ml (5.7) and 15.8% (15.5). Mean prostate volume was 43.6 cm(3). Seven patients complained of mild LUTS. DRE was suspicious in eight patients. Of the 15 men, 6 (40%) had adenocarcinoma on biopsy (all clinically confined to the prostate). Median (range) Gleason score was 6 (6-7). Median PCA3 score (range) before and after prostatic biopsy were respectively 36 (9-287) and 27 (5-287) with no significant difference between the two groups (sign test for matched series p > 0.05). The median variation between pre- and post-biopsy PCA3 was -18%. When considering a PCA3 cut-off of 35, two patients changed group: one patient had 51 before and 31 after (PSA 4.6; no cancer on prostate biopsy) and the second had 36 before and 27 after (PSA 5.6; low-risk PCa). The figure represents the PCA3 values for each case (squares for the pre-biopsy and diamonds for the post-biopsy). When considering only the six patients with PCA, median (mean) PCA3 score before and after prostatic biopsy were respectively 51.5 (60.8) and 44.5 (54.8) with no significant difference between the two groups (sign test for matched series p > 0.5) and a median variation between pre- and post-biopsy PCA3 of 1.5%.

CONCLUSIONS

Prostate biopsy did not alter significantly urinary PCA3 value. This confirms what was theoretically expected.

[Emerging biomarkers for the diagnosis, staging and prognosis of prostate cancer]

The introduction and widespread adoption of prostate-specific antigen (PSA) has revolutionized the way prostate cancer is diagnosed and treated. However, the use of PSA has also led to overdiagnosis and overtreatment of prostate cancer resulting in controversy about its use for screening. PSA also has limited predictive accuracy for predicting outcomes after treatment and for making clinical decisions about adjuvant and salvage therapies. Hence, there is an urgent need for novel biomarkers to supplement PSA for detection and management of prostate cancer. A plethora of promising blood- and urine-based biomarkers have shown promise in early studies and are at various stages of development (Human kallikrein 2, Early Prostate Cancer Antigen, Transforming Growth Factor-Beta 1 and Interleukin-6, Endoglin, PCA3, AMACR and ETS Gene Fusions). In this article, we review those biomarkers and then discuss the challenges a biomarker has to undergo before it is approved in a clinical use.