Targeting autophagy overcomes Enzalutamide resistance in castration-resistant prostate cancer cells and improves therapeutic response in a xenograft model

Macro-autophagy is associated with drug resistance in various cancers and can function as an adaptive response to maintain cell survival under metabolic stresses, including androgen deprivation. Androgen deprivation or treatment with androgen receptor (AR) signaling inhibitor (ARSI), Enzalutamide (MDV-3100, ENZA) or bicalutamide induced autophagy in androgen-dependent and in castration-resistant CaP (castration-resistant prostate cancer (CRPC)) cell lines. The autophagic cascade triggered by AR blockage, correlated with the increased light chain 3-II/I ratio and ATG-5 expression. Autophagy was observed in a subpopulation of C4-2B cells that developed insensitivity to ENZA after sustained exposure in culture. Using flow cytometry and clonogenic assays, we showed that inhibiting autophagy with clomipramine (CMI), chloroquine or metformin increased apoptosis and significantly impaired cell viability. This autophagic process was mediated by AMP-dependent protein kinase (AMPK) activation and the suppression of mammalian target of rapamycin (mTOR) through Raptor phosphorylation (Serine 792). Furthermore, small interfering RNA targeting AMPK significantly inhibited autophagy and promoted cell death in CaP cells acutely or chronically exposed to ENZA or androgen deprivation, suggesting that autophagy is an important survival mechanism in CRPC. Lastly, in vivo studies with mice orthotopically implanted with ENZA-resistant cells demonstrated that the combination of ENZA and autophagy modulators, CMI or metformin significantly reduced tumor growth when compared with control groups (P<0.005). In conclusion, autophagy is as an important mechanism of resistance to ARSI in CRPC. Antiandrogen-induced autophagy is mediated through the activation of AMPK pathway and the suppression of mTOR pathway. Blocking autophagy pharmacologically or genetically significantly impairs prostate cancer cell survival in vitro and in vivo, implying the therapeutics potential of autophagy inhibitors in the antiandrogen-resistance setting.

Standard of Care Versus Metastases-directed Therapy for PET-detected Nodal Oligorecurrent Prostate Cancer Following Multimodality Treatment: A Multi-institutional Case-control Study

BACKGROUND

Most prostate cancer (PCa) patients with a biochemical failure following primary multimodality treatment (surgery and postoperative radiotherapy) relapse in the nodes.

OBJECTIVE

To perform a matched-case analysis in men with lymph node recurrent PCa comparing standard of care (SOC) with metastasis-directed therapy (MDT).

DESIGN, SETTING, AND PARTICIPANTS

PCa patients with a prostate-specific antigen (PSA) progression following multimodality treatment were included in this retrospective multi-institutional analysis.

INTERVENTION

The SOC cohort (n=1816) received immediate or delayed androgen deprivation therapy administered at PSA progression. The MDT cohort (n=263) received either salvage lymph node dissection (n=166) or stereotactic body radiotherapy (n=97) at PSA progression to a positron emission tomography-detected nodal recurrence.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint, cancer-specific survival (CSS), was analyzed using the Kaplan-Meier method, log-rank test, Cox proportional hazards models, and propensity score-matched analyses.

RESULTS AND LIMITATIONS

At a median follow-up of 70 (interquartile range: 48-98) mo, MDT was associated with an improved CSS on univariate (p=0.029) and multivariate analysis (hazard ratio: 0.33, 95% confidence interval [CI]: 0.17-0.64) adjusted for the year of radical prostatectomy (RP), age at RP, PSA at RP, time from RP to PSA progression, Gleason score, surgical margin status, pT- and pN-stage. In total, 659 men were matched (3:1 ratio). The 5-yr CSS was 98.6% (95% CI: 94.3-99.6) and 95.7% (95% CI: 93.2-97.3) for MDT and SOC, respectively (p=0.005, log-rank). The main limitations of our study are its retrospective design and lack of standardization of systemic treatment in the SOC cohort.

CONCLUSIONS

MDT for nodal oligorecurrent PCa improves CSS as compared with SOC. These retrospective data from a multi-institutional pooled analysis should be considered as hypothesis-generating and inform future randomized trials in this setting.

PATIENT SUMMARY

Prostate cancer patients experiencing a lymph node recurrence might benefit from local treatments directed at these lymph nodes.

CEA-related cell adhesion molecule-1 is involved in angiogenic switch in prostate cancer

We demonstrate here that epithelial carcinoembryonic antigen (CEA)-related cell adhesion molecule-1 (CEACAM1) downregulation in prostate intraepithelial neoplasia (PIN) is inversely correlated with its upregulation in adjacent blood vessels. CEACAM1 silencing in prostate cancer cell line DU-145 via small interfering ribonucleic acid (siRNA) increased but its overexpression suppressed the expression of angiogenic/lymphangiogenic factors such as vascular endothelial growth factor (VEGF)-A, -C and -D, and angiogenic inhibitor collagen 18/endostatin. Furthermore, CEACAM1 overexpression in DU-145 cells increased but CEACAM1 silencing reduced angiopoietin-1 expression. Inverse relation was found for angiopoietin-2. Supernatant of CEACAM1-overexpressing DU-145 suppressed but that of CEACAM1-silenced increased the VEGF-induced endothelial tubes. Electron microscopically the majority of PIN-associated blood vessels was structurally destabilized exhibiting endothelial fenestration, trans- and inter-endothelial gaps. In some PIN areas, invasion of single tumor cells into the destabilized blood vessels was observed. These data show that disappearance of epithelial CEACAM1 in PIN is accompanied by its upregulation in adjacent vasculature which apparently correlates with vascular destabilization and increased vascularization of prostate cancer. Strategies to either conserve the epithelial CEACAM1 or to target endothelial CEACAM1 might be useful for an anti-angiogenic therapy of prostate cancer.

Critical analysis of a simplified Fuhrman grading scheme for prediction of cancer specific mortality in patients with clear cell renal cell carcinoma--Impact on prognosis

INTRODUCTION AND OBJECTIVES

The traditional 4-tiered Fuhrman grading system (FGS) is widely accepted as histopathological classification for clear cell renal cell carcinoma (ccRCC) and has shown prognostic value. As intra- and inter-observer agreement are sub-optimal, simplified 2- or 3-tiered FGSs have been proposed. We aimed to validate these simplified 2- or 3-tiered FGSs for prediction of cancer-specific mortality (CSM) in a large study population from 2 European tertiary care centers.

METHODS

We identified and followed-up 2415 patients with ccRCC who underwent radical or partial nephrectomy in 2 European tertiary care centers. Univariable and multivariable analyses and prognostic accuracy analyses were performed to evaluate the ability of several simplified FGSs (i.e. grades I + II vs., grades III + IV, grades I + II vs. grade III and grade IV) to predict CSM.

RESULTS

Independent predictor status in multivariate analyses was proved for the simplified 2-tiered FGS (high-grade vs. low-grade), for the simplified 3-tiered FGS (grades I + II vs. grade III and grade IV) as well as for the traditional 4-tiered FGS. The prognostic accuracy of multivariable models of 77% was identical for all tested models. Prognostic accuracy of the model without FG was 75%.

CONCLUSIONS

A simplified 2- or 3-tiered FGS could predict CSM as accurate as the traditional 4-tiered FGS in a large European study population. Application of new simplified 2- or 3-tiered FGS may reduce inter-observer-variability and facilitate clinical practice without compromising the ability to predict CSM in ccRCC patients after radical or partial nephrectomy.

Bildgebende Verfahren bei der Diagnose des Prostatakarzinoms

Prostate cancer is one of the most frequent malignant diseases in men. Despite constant progress achieved in imaging procedures, prostate biopsy is the gold standard for diagnosing prostate cancer. For the assessment of lymph node status, only staging lymphadenectomy provides valid information. The aim of this work is to analyze the imaging procedures available in Germany and their value in primary and lymph node staging as well as biochemical recurrence.

[PDE5 inhibitors. A new option in the treatment of ureteral colic?]

BACKGROUND

PDE5 inhibitors represent the gold standard in the medical therapy of erectile dysfunction (ED). Promising results have been published regarding further urological indications such as treatment of ureteral colic. The aim of the present study was to evaluate the functional effects of the PDE5 inhibitors sildenafil (SIL), vardenafil (VAR), and tadalafil (TAD) on tissue tension and cyclic nucleotide levels of human ureteral smooth muscle segments in vitro.

METHODS

Relaxant responses of human ureteral smooth muscle were investigated in vitro using the organ bath technique. Cyclic nucleotides cAMP and cGMP were determined by specific radioimmunoassays.

RESULTS

Relaxing effects of ureteral muscle tension were observed in the rank order VAR>SIL>TAD. While only VAR significantly elevated cGMP levels 3.3-fold over control, no increase for cAMP levels was observed.

CONCLUSIONS

Our data provide evidence that cGMP is involved in the control of the normal function of the smooth musculature of the human ureter. Our findings suggest the potential of using selective inhibitors of PDE isoenzymes in the treatment of ureteral colic.

The current role of precision surgery in oligometastatic prostate cancer

Oligometastatic prostate cancer (omPCa) is a novel intermediate disease state characterized by a limited volume of metastatic cells and specific locations. Accurate staging is paramount to unmask oligometastatic disease, as provided by prostate-specific membrane antigen-positron emission tomography. Driven by the results of prospective trials employing conventional and/or modern staging modalities, the treatment landscape of omPCa has rapidly evolved over the last years. Several treatment-related questions comprising the concept of precision strikes are under development. For example, beyond systemic therapy, cohort studies have found that cytoreductive radical prostatectomy (CRP) can confer a survival benefit in select patients with omPCa. More importantly, CRP has been consistently shown to improve long-term local symptoms when the tumor progresses across disease states due to resistance to systemic therapies. Metastasis-directed treatments have also emerged as a promising treatment option due to the visibility of oligometastatic disease and new technologies as well as treatment strategies to target the novel PCa colonies. Whether metastases are present at primary cancer diagnosis or detected upon biochemical recurrence after treatment with curative intent, targeted yet decisive elimination of disseminated tumor cell hotspots is thought to improve survival outcomes. One such strategy is salvage lymph node dissection in oligorecurrent PCa which can alter the natural history of progressive PCa. In this review, we will highlight how refinements in modern staging modalities change the classification and treatment of (oligo-)metastatic PCa. Further, we will also discuss the current role and future directions of precision surgery in omPCa.

[Radical prostatectomy in locally advanced prostate cancer]

BACKGROUND

Due to an inverse stage migration, the proportion of patients with more aggressive and locally advanced prostate cancer (PCa) has increased over the last few years. The natural history in these patients shows a higher risk of local complications and worse oncologic outcome.

OBJECTIVES

To analyze the impact of radical prostatectomy (RP) in patients with locally advanced PCa.

MATERIALS AND METHODS

A review of the literature was performed using PubMed and MEDLINE databases focusing on articles addressing locally advanced PCa.

RESULTS

Current guidelines recommend local therapy in patients with locally advanced PCa among other treatment options. Thereby no strong evidence favoring radiotherapy or RP is present. Compared to patients without local treatment, RP may improve oncologic outcome and decrease the risk of local complications. Due to more difficult surgery and an increased need of multimodal therapy, higher perioperative morbidity and worse functional outcomes compared to patients with localized PCa are reported. No reliable prospective data indicating a widespread use of neoadjuvant treatment exists. Indication for further adjuvant or salvage therapies depends on pathologic results and postoperative course.

CONCLUSIONS

RP is one of the treatment options with good long-term results which can be offered to patients with locally advanced PCa. Nevertheless, patients need to be counselled especially about the worse postoperative functional outcome compared to patients with localized PCa.

Ein Molekül, zwei Gesichter

BACKGROUND

Angiogenesis is a prerequisite for tumor growth and metastasis in which CEACAM1 plays an essential role.

PATIENTS AND METHODS

The role of CEACAM1 in vascularization and invasion of prostate and bladder cancer was studied.

RESULTS

Our analyses demonstrate an epithelial downregulation of CEACAM1 in superficial bladder tumors and in PIN of the prostate. Concurrently, CEACAM1 is upregulated in endothelial cells of tumor blood vessels. CEACAM1 knockdown in tumor cell lines of the prostate and urinary bladder via siRNA results in an increase of tumor vascularization while CEACAM1 overexpression in these cells suppresses it.

CONCLUSIONS

CEACAM1-induced signaling mechanisms play a role in induction of angiogenesis in superficial tumors of the prostate and bladder. Strategies to either conserve the epithelial CEACAM1 or to target endothelial CEACAM1 might be useful for an antiangiogenic therapy of bladder and prostate cancer.

Minimizing complications during retropubic radical prostatectomy - Is ureteral stenting necessary?

OBJECTIVES AND AIMS

To avoid damage to the ureters during bladder neck preparation in radical prostatectomy for prostate cancer, it may be helpful to insert ureteral stents temporarily or to intravenously administer indigo carmine dye for enhanced visualisation of ureteric orifices. We evaluated our bladder neck preserving technique at radical prostatectomy with regard to ureteric injuries.

PATIENTS AND METHODS

We analysed 369 consecutive radical prostatectomies operated in our clinic in a bladder neck preserving technique. The following parameters were assessed in this retrospective study: number of prophylactic ureteric stent insertions, application of indigo carmine dye, observed injuries of the ureters by the surgeon, postoperative increase of serum creatinine and postoperative status of kidney ultrasound.

RESULTS

In 7/369 prostatectomies (1.90%) a ureteric stent insertion was performed, indigo carmine was not applied to any patient at all, yet no intraoperative injury of a ureter was observed by a surgeon. No revision was necessary due to a ureteral injury within the observation period of one year after surgery. In 17 patients with preoperative normal creatinine value a pathological value was observed on the first postoperative day (mean 1.4 mg/dl). In these patients no consecutive postrenal acute renal failure was observed, no hydronephrosis was monitored by ultrasound and no further intervention was necessary.

CONCLUSIONS

Bladder neck preserving operation technique does not implicate the need of prophylactic ureteric stent insertions and has no higher incidence of ureteric injuries.

[Patients with bladder cancer in clinical stage T2 : survival benefit of downstaging in comparison to patients with confirmed muscle invasion in cystectomy specimens]

BACKGROUND

Few and partially contradictory data are available regarding the prognostic signature of downstaging of muscle-invasive clinical tumour stages in patients treated with radical cystectomy.

MATERIALS AND METHODS

Clinicopathological parameters of 1,643 patients (study group, SG) treated with radical cystectomy due to muscle-invasive urothelial bladder cancer were summarized in a multi-institutional database. Patients of the SG fulfilled the following conditions: clinical tumour stage T2 N0 M0 and no administration of neoadjuvant radiation or chemotherapy. Cancer-specific survival (CSS) rates were calculated referring to pathological tumour stages in cystectomy specimens (<pT2, pT2, >pT2) (mean follow-up: 51 months). Furthermore, a multivariable model integrating clinical information was developed in order to predict the probability of downstaging.

RESULTS

A total of 173 patients (10.5%) of the SG presented with downstaging in pathological tumour stages (pT0: 4.8%, pTa: 0.4%, pTis: 1.3%, pT1: 4.1%); 12 of these patients had positive lymph nodes (7%, in comparison with 21% pN+ of pT2 tumours and 43% of >pT2 tumours). Patients with tumour stages <pT2, pT2 and >pT2 had CSS rates after 5 years of 89, 69 and 46%, respectively (p<0.001). In a multivariable Cox model the presence of pathological downstaging resulted in a significant reduction of cancer-specific mortality (HR 0.30; 95% CI 0.18-0.50). By logistic regression analysis the date of TURB (benefit for more recent operations) was identified as the only independent predictor for downstaging of muscle-invasive clinical tumour stages. Age, gender, grading and associated Tis in the TURB did not reveal any significant influence.

CONCLUSION

Patients with muscle-invasive clinical tumour stages and downstaging in cystectomy specimens represent a subgroup with significantly enhanced CSS rates. Further trials that integrate the parameters tumour size, stages cT2a vs cT2b and focality are required in order to define the independent prognostic signature of downstaging of tumour stages more precisely.

[Organ-sparing surgery for penile cancer]

In patients with penile cancer health-related quality of life is closely related to organ-sparing surgery. To achieve an ideally suited treatment modality for this rare but aggressive tumor entity different operating techniques like micrographic surgery, laser treatment, and glansectomy were developed. These should offer optimal oncological treatment while preserving sexual function. This article gives an overview of indications and limits of organ-sparing treatment in penile cancer.

[Diagnostic work-up for lymph node metastases of urological tumors]

Both CT and MRI are currently the most frequently used and recommended modalities for lymph node staging of uro-oncological diseases. Their diagnostic usefulness is limited particularly for recognition of micrometastases and lymph nodes <10 mm. FDG- and choline-based PET/CT procedures also do not offer much improvement in these cases. Meanwhile however PET/CT has been included in the EAU guidelines for seminomas and is recommended for further management of residual tumors after chemotherapy. Magnetic resonance imaging with lymphotropic monocrystalline iron oxide nanoparticles appears to exhibit great potential and can detect smaller metastases and micrometastases even in normal-sized lymph nodes in uro-oncological diseases. Nevertheless, Guerbet has withdrawn its application to the EMEA for marketing authorization of its product Sinerem (superparamagnetic iron oxide nanoparticles). In the meantime diffusion-weighted MRI represents a promising technique and is already being evaluated in fields outside the realm of urology.

Comparison of guideline recommendations with daily practice in patients with renal cell carcinoma

Objectives and Aims

To compare guideline recommendations with daily practice patterns in a German patient cohort with renal cell carcinoma.

Patients and methods

81 patients with T1 oder T2 renal cell carcinoma (RCC) were included in this prospective single-center study. All patients were operated in a single institution either by open radical nephrectomy (ORN) or nephron sparing surgery (NSS). Patients and doctors were evaluated using a written questionnaire with a follow-up of 12 months. Follow-up intervals, follow-up modalities (e. g. imaging modalities, laboratory controls of blood and urine) and the call on psycho-oncological support were evaluated.

Results

The majority of patients (72%) were followed up by their urologists. Follow-up examinations included abdominal ultrasound, urine and blood diagnostics, conventional chest x-rays, computed tomography (CT) of abdomen, chest or head or abdominal Magnetic Resonance Imaging (MRI). There were no significant differences between patients operated by ORN or NSS. In total, 12.5% of patients were asking for psycho-oncological support.

Conclusions

In general, patients were followed up according to existing guideline recommendations. Only a small proportion of patients asked for psycho-oncological treatment.

[Current controversies in the treatment of localized prostate cancer]

In the prostate-specific antigen (PSA) era, most prostate cancers (PCa) are diagnosed in a localized stage and a plethora of therapeutic options are warranted in different clinical settings and disease stages of localized PCa. In the current narrative review, we give an overview of the current controversies in the therapeutic landscape of localized PCa and focus on organ-sparing approaches, percutaneous radiotherapy, brachytherapy as well as retropubic and robot-assisted prostatectomy by summarizing studies that have been published within the last two years.