Drivers of Radioresistance in Prostate Cancer

TRAIL-driven targeting and reversing cervical cancer radioresistance by seleno-nanotherapeutics through regulating cell metabolism

Recently, radioresistance has become a major obstacle in the radiotherapy of cervical cancer. To demonstrate enhanced radiosensitization against radioresistant cervical cancer, radioresistant cervical cancer cell line was developed and the mechanism of radioresistance was explored. Due to the overexpression of (death receptor 5, DR5) in cervical cancer, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-overexpressed cervical cancer cell membrane-camouflaged Cu2-xSe nanomedicine (CCMT) was designed. Since the CCMT was encapsulated with TRAIL-modified cell membrane, it represented high target to cervical cancer cell and immune evasion. Furthermore, Cu2-xSe had the ability to scavenge glutathione (GSH) and produce ·OH with excess H2O2 in the tumor microenvironment. The presence of CCMT combined with radiation therapy could effectively increase the 1O2 produced by X-rays. In vitro and in vivo studies elaborated that CCMT exhibited excellent radiosensitization properties to reverse radiotolerance by scavenging GSH and promoting DNA damage, apoptosis, mitochondrial membrane potential damage and metabolic disruption. Collectively, this study suggested that the development of TRAIL-overexpressed cell membrane-camouflaged Cu2-xSe nanomedicine could advance future cervical cancer treatment and minimize the disadvantages associated with radiation treatment.

The synergistic effects of betanin and radiotherapy in a prostate cancer cell line: an in vitro study

BACKGROUND

Prostate cancer is among the most common cancers in men with an increasing incidence rate. Radiation therapy (RT) is a therapeutic strategy for the management of prostate cancer after surgery; nonetheless, it has different side effects on neighboring healthy cells/tissues. Moreover, radioresistance has been an increasing phenomenon in the recent years. Therefore, there is an urgent need for the introduction of a safe and effective radiosensitizing agent. Accordingly, the recent trend in the development of novel drugs is accompanied by a push toward natural compounds. Our study evaluated the effects of betanin combined with RT as a potential radiosensitizing agent in the PC-3 cell line.

METHODS AND RESULTS

MTT assay was utilized to determine the growth inhibitory impact of betanin. The possible synergistic effect was evaluated with CompuSyn software upon Trypan blue exclusion test. Apoptosis-related gene expression was evaluated via Real-time PCR and the protein expression of P21 was determined using western blotting. A synergistic anticancer effect with an optimal combination index of 0.61 was achieved by treating PC-3 cells with betanin and RT. The results pointed out that betanin synergistically triggered RT-mediated apoptosis and cell cycle arrest through modulating gene and protein expression in comparison with each of the monotherapies.

CONCLUSION

These findings shed light on the synergistic antitumor effect of betanin and RT in prostate cancer, indicating the potential use of betanin as a radiosensitizer agent.

Addressing the Reciprocal Crosstalk between the AR and the PI3K/AKT/mTOR Signaling Pathways for Prostate Cancer Treatment

The reduction in androgen synthesis and the blockade of the androgen receptor (AR) function by chemical castration and AR signaling inhibitors represent the main treatment lines for the initial stages of prostate cancer. Unfortunately, resistance mechanisms ultimately develop due to alterations in the AR pathway, such as gene amplification or mutations, and also the emergence of alternative pathways that render the tumor less or, more rarely, completely independent of androgen activation. An essential oncogenic axis activated in prostate cancer is the phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway, as evidenced by the frequent alterations of the negative regulator phosphatase and tensin homolog (PTEN) and by the activating mutations in PI3K subunits. Additionally, crosstalk and reciprocal feedback loops between androgen signaling and the PI3K/AKT/mTOR signaling cascade that activate pro-survival signals and play an essential role in disease recurrence and progression have been evidenced. Inhibitors addressing different players of the PI3K/AKT/mTOR pathway have been evaluated in the clinic. Only a limited benefit has been reported in prostate cancer up to now due to the associated side effects, so novel combination approaches and biomarkers predictive of patient response are urgently needed. Here, we reviewed recent data on the crosstalk between AR signaling and the PI3K/AKT/mTOR pathway, the selective inhibitors identified, and the most advanced clinical studies, with a focus on combination treatments. A deeper understanding of the complex molecular mechanisms involved in disease progression and treatment resistance is essential to further guide therapeutic approaches with improved outcomes.

Efficacy and Complications of the Re-Adjustable Male Sling System for Stress Urinary Incontinence after Radical Prostatectomy

The aim of this study was to investigate the outcomes of re-adjustable male slings in pa-tients with postoperative stress urinary incontinence (SUI) following radical prostatectomy (RP). We retrospectively analyzed 18 patients with SUI following RP for prostate cancer, who were treated with re-adjustable male slings from January 2016 to December 2021. The clinical outcomes were evaluated based on daily pad usage and urodynamic studies, both preoperatively and post-operatively. The degree of SUI was categorized as either mild, moderate, or severe. Success was defined as no more pad use or significantly decreased pad use. Complications were classified ac-cording to the Clavien-Dindo system. The mean age of patients was 70.4 ± 5.9 years, and 61.1% of cases were diagnosed as locally advanced prostate cancer. Mild, moderate, and severe SUI were reported as 33.3%, 50.0%, and 16.7%, respectively. The average daily pad use after RP was 3.3 pads and there was a significant reduction in the number of daily pads used after the re-adjustable male sling procedure (3.3 vs. 1.3; p = 0.002). Overall, the operation was considered successful in 11 pa-tients (61.1%), 1 case showed improvement (5.6%), and it was considered unsuccessful in 6 patients (33.3%). Impressively, in the severe incontinence subgroup (three patients), one (33.3%) had im-provement and one (33.3%) had success. Transient perineal discomfort after the operation was the most common complaint. However, two patients had severe complications with bowel injury during sling implantation (Clavien-Dindo grade III). The re-adjustable male sling system was an efficient surgical treatment option for post-RP SUI, even in a locally advanced disease dominant population. One should pay attention to the complication of bowel perforation during surgery.