Prostate carcinoma I: prognostic factors in radical prostatectomy specimens and pelvic lymph nodes

Tumor-derived OBP2A promotes prostate cancer castration resistance

Androgen deprivation therapy (ADT) is a systemic therapy for advanced prostate cancer (PCa); although most patients initially respond to ADT, almost all cancers eventually develop castration-resistant PCa (CRPC). Currently, most research focuses on castration-resistant tumors, and the role of tumors in remission is almost completely ignored. Here, we report that odorant-binding protein (OBP2A) released from tumors in remission during ADT catches survival factors, such as CXCL15/IL8, to promote PCa cell androgen-independent growth and enhance the infiltration of myeloid-derived suppressor cells (MDSCs) into tumor microenvironment, leading to the emergence of castration resistance. OBP2A knockdown significantly inhibits CRPC and metastatic CRPC development and improves therapeutic efficacy of CTLA-4/PD-1 antibodies. Treatment with OBP2A-binding ligand α-pinene interrupts the function of OBP2A and suppresses CRPC development. Furthermore, α-pinene-conjugated doxorubicin/docetaxel can be specifically delivered to tumors, resulting in improved anticancer efficacy. Thus, our studies establish a novel concept for the emergence of PCa castration resistance and provide new therapeutic strategies for advanced PCa.

Targeting INMT and interrupting its methylation pathway for the treatment of castration resistant prostate cancer

Background

Castration-resistant prostate cancer (CRPC) is associated with a very poor prognosis, and the treatment of which remains a serious clinical challenge.

Methods

RNA-seq, qPCR, western blot and immunohistochemistry were employed to identify and confirm the high expression of indolethylamine N-methyltransferase (INMT) in CRPC and the clinical relevance. Chip assay was used to identify Histone-Lysine N-Methyltransferase (SMYD3) as a major epigenetic regulator of INMT. LC-MS/MS were used to identify new substrates of INMT methylation in CRPC tissues. Gene knockdown/overexpression, MTT and mouse cancer models were used to examine the role of INMT as well as the anticancer efficacy of INMT inhibitor N,N-dimethyltryptamine (DMT), the SMYD3 inhibitor BCl-12, the selenium compounds methaneseleninic acid (MSA) and Se-(Methyl)selenocysteine hydrochloride (MSC), and the newly identified endogenous INMT substrate Bis(7)-tacrine.

Results

We found that the expression of INMT was highly increased in CRPC and was correlated with poor prognosis of clinical prostate cancer (PCa). INMT promoted PCa castration resistance via detoxification of anticancer metabolites. Knockdown of INMT or treatment with INMT inhibitor N,N-dimethyltryptamine (DMT) significantly suppressed CRPC development. Histone-Lysine N-Methyltransferase SMYD3 was a major epigenetic regulator of INMT expression, treatment with SMYD3 inhibitor BCl-121 suppressed INMT expression and inhibits CRPC development. Importantly, INMT knockdown significantly increased the anticancer effect of the exogenous selenium compounds methaneseleninic acid (MSA) and Se-(Methyl)selenocysteine hydrochloride (MSC) as well as the endogenous metabolite Bis(7)-tacrine.

Conclusions

Our study suggests that INMT drives PCa castration resistance through detoxification of anticancer metabolites, targeting INMT or its regulator SMYD3 or/and its methylation metabolites represents an effective therapeutic avenue for CRPC treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02109-z.

The prognostic impact of downgrading and upgrading from biopsy to radical prostatectomy among men with Gleason score 7 prostate cancer

BACKGROUND

Recently, a new prostate cancer (PC) grading system was introduced, where Gleason score (GS) 7 was divided into 3 + 4 = 7 and 4 + 3 = 7 due to the different prognoses associated with each tumor type. However, whether downgrading or upgrading from needle biopsy (NB) to radical prostatectomy (RP) affects oncologic outcomes is currently unknown. Herein, we investigated the prognostic impact of downgrading and upgrading from NB to RP among men with GS 7 PC.

METHODS

We retrospectively reviewed the medical records of 3003 patients with localized PC who underwent RP between 2005 and 2014. We included 692 patients with GS 7 PC on both NB and RP specimens. We analyzed the data using Kaplan-Meier methods and Cox proportional hazard models.

RESULTS

Of the 692 patients enrolled in this study, 389 (56.2%) and 303 (43.8%) patients had RP GS 3 + 4 = 7 and RP GS 4 + 3 = 7 PC, respectively. On the basis of NB and RP GS, 264 (38.1%), 125 (18.1%), 142 (20.5%), and 161 (23.3%) patients were classified as 3 + 4/3 + 4, 4 + 3/3 + 4, 3 + 4/4 + 3, and 4 + 3/4 + 3, respectively. Kaplan-Meier curves showed significant differences in biochemical recurrence (BCR)-free survival across the groups (P < .001). In the multivariate analyses, these groups were significantly associated with BCR (4 + 3/3 + 4: hazard ratio [HR], 1.675; 3 + 4/4 + 3: HR, 1.908; and 4 + 3/4 + 3: HR, 2.699).

CONCLUSIONS

Downgrading and upgrading from NB to RP was an independent predictor of BCR in men with GS 7 PC, which could be due to the amount of Gleason pattern 4.

The expression of p-mTOR and COUP-TFII correlates with increased lymphangiogenesis and lymph node metastasis in prostate adenocarcinoma

BACKGROUND

Mammalian target of rapamycin (mTOR) is a central regulator of major cellular processes such as growth and proliferation. Deregulated mTOR signaling is implicated in a wide spectrum of human malignancies including prostate cancer. The aim of this study is to address the role of phosphorylated mTOR (p-mTOR) in prostate adenocarcinoma-induced lymphangiogenesis and lymph node metastasis as well as to investigate its relationship with chicken ovalbumin upstream promoter transcriptional factor 2 (COUP-TFII) and the vascular endothelial growth factors A/C (VEGF A/C).

METHODS

We analyzed 92 paraffin embedded specimens from patients with prostate cancer who underwent radical prostatectomy with pelvic lymph node (LN) dissection. Twenty-four of these men were pathologically assessed to have regional LN metastasis (pN1 group) and 68 with negative lymph nodes (pN0 group). Lymph vessel density was measured using anti-D2-40 and anti-LYVE-1 antibodies. The expression of p-mTOR, COUP-TFII, and VEGF A/C was also evaluated by immunohistochemistry.

RESULTS

Specimens from pN1 group exhibited higher cytoplasmic p-mTOR expression compared to pN0 specimens. Mean vessel densities assessed by COUP-TFII and D2-40 were increased in pN1 tumors and positively associated with higher p-mTOR expression. Interestingly, increased expression of p-mTOR was positively associated with COUP-TFII expression in cancer cells and elevated immunoreactivity for both VEGF A and C, which in turn exhibited higher expression in pN1 group.

CONCLUSIONS

Our findings suggest that increased p-mTOR and COUP-TFII expression are implicated in human prostate adenocarcinoma-induced lymphangiogenesis and LN metastasis.

Clinical, pathological and molecular prognostic factors in prostate cancer decision-making process

Prostate cancer is the most common urologic neoplasm and the second leading cause of cancer-related death among men in many developed countries. Given the highly heterogeneous behaviour of the disease, there is a great need for prognostic factors, in order to stratify the clinical risk and give the best treatment options to the patient. Clinical factors, such as prostate-specific antigen value and derivatives, and pathological factors, such as stage and Gleason grading, are well kown prognostic factors. Nomograms can provide useful prediction in each clinical sceario. The field of molecular biomarkers is briskly evolving towards personalized medicine. TMPRSS2-ERG fusion, deletion of PTEN ed and gene panels are some of the more extensively explored molecular features in prostate cancer outcome prediction. In the near future, circulating tumour cells, exosomes and microRNAs could give us further, not invasive important tools.

Prognostic Significance of Lymphatic Vessel Density Detected by D2-40 and Its Relation to Claudin-4 Expression in Prostatic Adenocarcinoma

Background Lymphovascular invasion is an important pathway of metastatic spread and regional lymph node metastasis is the major prognostic factor in prostatic adenocarcinoma. D2-40 is used to identify the lymphatic vessels and to assess the lymphatic vessel density (LVD). Expression of claudin-4 may be related to invasion and progression of carcinoma cells in several primary tumors. Aim To evaluate intra- and peritumoral LVD through immunohistochemical expression of D2-40 in relation to claudin-4 expression and clinicopathological parameters in prostatic adenocarcinoma. Materials and Methods Immunohistochemical staining procedure was performed on 53 paraffin-embedded blocks of radical prostatectomy specimens for prostatic adenocarcinoma using anti D2-40 and claudin-4 antibodies. Sections were evaluated for mean LVD in intratumoral and peritumoral tissues assessed by D2-40 expression. Results LVD in intratumoral tissues was significantly lower compared with peritumoral areas (P = .0001). Peritumoral mean LVD was significantly higher in cases with lymphovascular invasion (P = .041) and in cases with positive lymph node metastasis (P = .003) than intratumoral mean LVD. High claudin-4 expression was significantly correlated with high tumor grade (P = .0001), lymphovascular invasion (P = .006), and positive lymph node metastasis (P = .004). High claudin-4 expression was significantly associated with increased mean LVD in peritumoral tissues. Conclusion Increased peritumoral mean LVD in prostatic adenocarcinoma is associated with lymphovascular invasion and positive lymph node metastasis. High claudin-4 expression is associated with high tumor grade, lymphocascular invasion, positive lymph node metastasis, and high mean peritumoral LVD suggesting that D2-40 and claudin-4 may represent different mechanisms of lymphatic vessel invasion with both biomarkers is related to poor prognosis.

The expression of vascular endothelial growth factor-C correlates with lymphatic microvessel density and lymph node metastasis in prostate carcinoma: An immunohistochemical study

Aim:

To evaluate the expression of two different lymphatic vascular density (LVD) markers (D2-40 and LYVE-1) and a lymphangiogenic cytokine (Vascular Endothelial Growth Factor-C, [VEGF-C]) in prostate carcinoma and to investigate their relationship with the lymph node status.

Settings and Design:

Archival material study of 92 non-consecutive radical prostatectomy specimens.

Materials and Methods:

The mean LVD was assessed immunohistochemically in 24 prostate carcinoma specimens from patients with clinically localized disease, who were found to have nodal metastasis (pN1), and was compared with 68 pN0 cases. Furthermore, the mean LVD, VEGF-C expression, and lymphatic invasion were examined in relation to lymph node involvement.

Results:

Peritumoral (but not intratumoral) mean LVD assessed by D2-40 was higher in pN1 tumors (P = 0.015). LYVE-1 expression was limited and not associated with lymph node status. The VEGF-C expression was higher in the N1 cases and also correlated with the increased mean LVD in both the peri- and intratumoral compartments. Lymphatic invasion was strongly associated with nodal metastasis and higher VEGF-C expression.

Conclusions:

Our results indicate that increased peritumoral (but not intratumoral) LVD in the tumor specimen is associated with lymph node metastasis. Increased expression of VEGF-C is associated with higher LVD (in both intratumoral and peritumoral compartments) and with positive lymph node status, indicating a possible dual role in both lymphangiogenesis and lymphatic vessel invasion.

Morphological Analysis of Radical Prostatectomy Specimens: Recent Topics Relevant to Prognosis

The pathology report should include clinically relevant information as well as provide clinically useful information derived from the macroscopic examination and microscopic evaluation of the radical prostatectomy (RP) specimens. The reporting pathologist should pay particular attention to the evaluation of the prognostic factors proven to be of prognostic importance and useful in clinical patient management, including histological type, grade and volume of cancer, the extent of local invasion and stage of cancer as well as the surgical margins status.

High-level cytoplasmic cyclin D1 expression in lymph node metastases from prostate cancer independently predicts early biochemical failure and death in surgically treated patients

AIMS

To test the prognostic significance of cyclin D1 in nodal-positive prostate cancer.

METHODS AND RESULTS

Nuclear and cytoplasmic cyclin D1 expression was evaluated in 119 nodal-positive prostate cancer patients undergoing radical prostatectomy and extended lymphadenectomy. Cyclin D1 was correlated with various tumour features and biochemical recurrence-free survival (bRFS), disease-specific survival (DSS) and overall survival (OS). In the metastases, high-level cytoplasmic cyclin D1 expression independently predicted poor outcome (5-year bRFS, 12.5% versus 26.4%, P = 0.006; 5-year DSS, 56.3% versus 80.7%, P = 0.007; 5-year OS, 56.3% versus 78.7%, P = 0.011). These patients had a 2.62-fold elevated risk of dying from prostate cancer as compared with patients with low-level cytoplasmic cyclin D1 expression (P = 0.024). All other subcellular compartments of cyclin D1 expression in primary tumours and metastases were prognostically non-significant.

CONCLUSIONS

The subcellular location of cyclin D1 expression in prostate cancer is linked to specific clinical courses. Survival stratification according to biomarker expression in metastases indicates an important role for tumour sampling from these tissues.

Undergrading and understaging in patients with clinically insignificant prostate cancer who underwent radical prostatectomy

PURPOSE

The aim of our study is to evaluate the undergrading and understaging rates in patients with clinically localized insignificant prostate cancer who underwent radical prostatectomy.

MATERIALS AND METHODS

Between July 2005 and July 2008, 406 patients underwent radical prostatectomy for clinical localized prostate cancer in our hospital. Based on preoperative data, 93 of these patients fulfilled our criteria of non-significance: Gleason score < 7, stage T1c, PSA < 10 ng/mL and percentage of affected fragments less than 25%. The pathologic stage and Gleason score were compared to preoperative data to evaluate the rate of understaging and undergrading. The biochemical recurrence free survival of these operated insignificant cancers were also evaluated.

RESULTS

On surgical specimen analysis 74.7% of patients had Gleason score of 6 or less and 25.3% had Gleason 7 or greater. Furthermore 8.3% of cases showed extracapsular extension. After 36 months of follow-up 3.4% had biochemical recurrence, defined by a PSA above 0.4 ng/mL.

CONCLUSIONS

Despite the limited number of cases, we have found considerable rates of undergrading and understaging in patients with prostate cancer whose current definitions classified them as candidates for active surveillance. According to our results the current definition seems inadequate as up to a third of patients had higher grade or cancer outside the prostate.

Expression of microRNAs and protein-coding genes associated with perineural invasion in prostate cancer

BACKGROUND

Perineural invasion (PNI) is the dominant pathway for local invasion in prostate cancer. To date, only few studies have investigated the molecular differences between prostate tumors with PNI and those without it.

METHODS

To evaluate the involvement of both microRNAs and protein-coding genes in PNI, we determined their genome-wide expression with a custom microRNA microarray and Affymetrix GeneChips in 50 prostate adenocarcinomas with PNI and 7 without it. In situ hybridization (ISH) and immunohistochemistry was used to validate candidate genes.

RESULTS

Unsupervised classification of the 57 adenocarcinomas revealed two clusters of tumors with distinct global microRNA expression. One cluster contained all non-PNI tumors and a subgroup of PNI tumors. Significance analysis of microarray data yielded a list of microRNAs associated with PNI. At a false discovery rate (FDR)<10%, 19 microRNAs were higher expressed in PNI tumors than in non-PNI tumors. The most differently expressed microRNA was miR-224. ISH showed that this microRNA is expressed by perineural cancer cells. The analysis of protein-coding genes identified 34 transcripts that were differently expressed by PNI status (FDR<10%). These transcripts were down-regulated in PNI tumors. Many of those encoded metallothioneins and proteins with mitochondrial localization and involvement in cell metabolism. Consistent with the microarray data, perineural cancer cells tended to have lower metallothionein expression by immunohistochemistry than nonperineural cancer cells.

CONCLUSIONS

Although preliminary, our findings suggest that alterations in microRNA expression, mitochondrial function, and cell metabolism occur at the transition from a noninvasive prostate tumor to a tumor with PNI.

Nuclear cytokine-activated IKKalpha controls prostate cancer metastasis by repressing Maspin

Inflammation enhances tumour promotion through NF-kappaB-dependent mechanisms. NF-kappaB was also proposed to promote metastatogenesis through epithelial-mesenchymal transition. Yet a mechanistic link between inflammation and metastasis is missing. We identified a role for IkappaB kinase alpha (IKKalpha), activated by receptor activator of NF-kappaB (RANK/TNFRSF11A), in mammary epithelial proliferation during pregnancy. Owing to similarities between mammary and prostate epithelia, we examined IKKalpha involvement in prostate cancer and its progression. Here we show that a mutation that prevents IKKalpha activation slows down CaP growth and inhibits metastatogenesis in TRAMP mice, which express SV40 T antigen in the prostate epithelium. Decreased metastasis correlated with elevated expression of the metastasis suppressor Maspin, the ablation of which restored metastatic activity. IKKalpha activation by RANK ligand (RANKL/TNFSF11) inhibits Maspin expression in prostate epithelial cells, whereas repression of Maspin transcription requires nuclear translocation of active IKKalpha. The amount of active nuclear IKKalpha in mouse and human prostate cancer correlates with metastatic progression, reduced Maspin expression and infiltration of prostate tumours with RANKL-expressing inflammatory cells. We propose that tumour-infiltrating RANKL-expressing cells lead to nuclear IKKalpha activation and inhibition of Maspin transcription, thereby promoting the metastatic phenotype.