Selective HDAC6 Inhibition Has the Potential for Anti-Cancer Effect in Renal Cell Carcinoma.

Despite significant advancements in systemic therapy for renal cell carcinoma (RCC), the prognosis for patients with metastatic RCC remains poor, as they are often incurable. Consequently, there is an urgent need for innovative therapeutic strategies to further enhance the efficacy of RCC treatment and improve patient outcomes. One such promising avenue lies in targeting histone deacetylase (HDAC) 6, a protein known to regulate numerous crucial biological processes implicated in cancer progression by modulating the acetylation status of various cytoplasmic proteins. To explore the therapeutic potential of HDAC6 inhibition in RCC, our study focused on investigating the effects of HDAC6 inhibitors on cultured RCC cells. Utilizing a panel of 12 small molecule selective HDAC6 inhibitors and employing genetic knockdown techniques, we examined the impact of HDAC6 inhibition on RCC cellular dynamics. Our findings revealed that HDAC6 inhibition exerted a profound effect on RCC cells, resulting in decreased cell viability and DNA replication. Importantly, this effect was attributed to the induction of apoptosis. Our study provides valuable insights into the mechanisms underlying the anticancer effects of selective HDAC6 inhibitors on RCC. A detailed understanding of the molecular mechanisms underlying the anticancer effects of HDAC6 inhibition is important to explore new therapeutic strategies for metastatic RCC.

MicroRNAs as Potential Regulators of GSK-3ß in Renal Cell Carcinoma.

The prognosis of patients with advanced renal cell carcinoma (RCC) has improved with newer therapies, including molecular-targeted therapies and immuno-oncology agents. Despite these therapeutic advances, many patients with metastatic disease remain uncured. Inhibition of glycogen synthase kinase-3ß (GSK-3ß) is a promising new therapeutic strategy for RCC; however, the precise regulatory mechanism has not yet been fully elucidated. MicroRNAs (miRNAs) act as post-translational regulators of target genes, and we investigated the potential regulation of miRNAs on GSK-3ß in RCC. We selected nine candidate miRNAs from three databases that could potentially regulate GSK-3ß. Among these, hsa-miR-4465 (miR-4465) was downregulated in RCC cell lines and renal cancer tissues. Furthermore, luciferase assays revealed that miR-4465 directly interacted with the 3' untranslated region of GSK-3ß, and Western blot analysis showed that overexpression of miR-4465 significantly decreased GSK-3ß protein expression. Functional assays showed that miR-4465 overexpression significantly suppressed cell invasion of A498 and Caki-1 cells; however, cell proliferation and migration were suppressed only in Caki-1 and A498 cells, respectively, with no effect on cell cycle and apoptosis. In conclusion, miR-4465 regulates GSK-3ß expression but does not consistently affect RCC cell function as a single molecule. Further comprehensive investigation of regulatory networks is required in this field.

Targeting Pro-Survival Autophagy Enhanced GSK-3ß Inhibition-Induced Apoptosis and Retarded Proliferation in Bladder Cancer Cells.

Advanced bladder cancer (BC) (local invasive and/or metastatic) is not curable even with cytotoxic chemotherapy, immune checkpoint inhibitors, and targeted treatment. Targeting GSK-3ß is a promising novel approach in advanced BC. The induction of autophagy is a mechanism of secondary resistance to various anticancer treatments. Our objectives are to investigate the synergistic effects of GSK-3ß in combination with autophagy inhibitors to evade GSK-3ß drug resistance. Small molecule GSK-3ß inhibitors and GSK-3ß knockdown using siRNA promote the expression of autophagy-related proteins. We further investigated that GSK-3ß inhibition induced the nucleus translocation of transcription factor EB (TFEB). Compared to the GSK-3ß inhibition alone, its combination with chloroquine (an autophagy inhibitor) significantly reduced BC cell growth. These results suggest that targeting autophagy potentiates GSK-3ß inhibition-induced apoptosis and retarded proliferation in BC cells.

Tumor-infiltrating immune cell status predicts successful response to immune checkpoint inhibitors in renal cell carcinoma.

Immune checkpoint inhibitors (ICI) have dramatically changed the treatment of metastatic renal cell carcinoma (mRCC). Although many studies have reported biomarkers as predicting the efficacy of ICI in mRCC, they remain controversial and have challenges to apply in real-world practice. We evaluated prognostic significance of multiple molecules associated with tumor immunity in patients treated with ICI. The molecules were detected in tumor tissues by immunohistochemical staining. We identified CD8-positive T cells and CD68-positive macrophages infiltrating into the tumor tissue as significant favorable prognostic factors for ICI treatment. Conversely, high expression of CD4-positive T cells was associated with poor response to ICI. Furthermore, we demonstrated that scoring for the expression status of these three molecules provides a remarkably accurate biomarker in patients with mRCC. Even the classical approach of immunohistochemistry could predict the outcome of ICI treatment by assessing the combined status of tumor-infiltrating immune cells.

Advanced Bladder Cancer: Changing the Treatment Landscape.

Bladder cancer is the 10th most common cancer type in the world. There were more than 573,000 new cases of bladder cancer in 2020. It is the 13th most common cause of cancer death with an estimated more than 212,000 deaths worldwide. Low-grade non-muscle-invasive bladder cancer (NMIBC) is usually successfully managed with transurethral resection (TUR) and overall survival for NMIBC reaches 90% according to some reports. However, long-term survival for muscle-invasive bladder cancer (MIBC) and metastatic bladder cancer remains low. Treatment options for bladder cancer have undergone a rapid change in recent years. Immune checkpoint inhibitors (ICI), targeted therapies, and antibody-drug conjugates are available now. As bladder cancer is genetically heterogeneous, the optimization of patient selection to identify those most likely to benefit from a specific therapy is an urgent issue in the treatment of patients with bladder cancer.

Development of patient­derived tumor organoids and a drug testing model for renal cell carcinoma.

The selection of effective therapeutic agents is critical for improving the survival of patients with renal cell carcinoma (RCC). The aim of the present study was to develop an ex vivo drug testing assay using patient­derived tumor organoid (TO) cultures. For this purpose, surgical tumor specimens were obtained from 20 patients with RCC. TOs were developed ex vivo from freshly resected RCC tumors, and their histopathological and molecular characteristics were evaluated using histological staining and whole­exome sequencing (WES). Using a cell viability assay, the therapeutic efficacy of standard of care tyrosine kinase inhibitors in RCC TOs was determined. It was found that TOs recapitulated the histological features of primary RCC tumors. Using WES, a strong concordance was identified at the genetic level between the primary tumors and their corresponding TOs. Using patient­derived TO models, a prototype of an ex vivo drug testing assay was developed, and it was found that RCC TOs exhibited differential responses to sunitinib, pazopanib, cabozantinib, axitinib and sorafenib treatment. On the whole, although the predictive value of the current assay has to be tested and validated in future clinical studies, the findings of the present study demonstrate a novel approach for ex vivo drug testing in patient­derived TO models, which may have potential for use in the personalized treatment of cancer patients.

Histone deacetylase 6 inhibition in urothelial cancer as a potential new strategy for cancer treatment.

Histone deacetylases (HDACs) are enzymes that remove acetyl groups from histones and have attracted attention as potential targets for cancer therapy. Several small molecule inhibitors have been developed to target HDACs; however, clinical trials of pan-HDAC inhibitors have found these types of inhibitors to be inefficient and to be relatively highly toxic. In the present study, the role of one HDAC isozyme, HDAC6, in urothelial cancer was investigated. Protein expression levels and subcellular localization of HDAC6 was identified in surgically resected bladder tumors using immunohistochemistry. The antitumor effects of 12 small molecule HDAC6 inhibitors were also examined in vitro using cultured urothelial cancer cells. The HDAC6 inhibitors decreased cell viability, with IC50 values in the low µM range, as low as 2.20 µM. HDACi D, E and F had the lowest IC50 values. HDAC6 has been previously reported to regulate programmed death-ligand 1 (PD-L1) and PD-L1 expression was found to be a predictor of decreased overall survival time. There was no association between the protein expression level of HDAC6 and PD-L1 in tumor tissues; however, HDAC6 inhibition by specific small molecule inhibitors resulted in decreased expression levels of membranous PD-L1 in cultured urothelial cancer cell lines. The results suggested that inhibition of HDAC6 could be a promising novel approach for the treatment of urothelial cancer.

Intraoperative intraocular pressure changes during robot-assisted radical prostatectomy: associations with perioperative and clinicopathological factors.

BACKGROUND: Steep Trendelenburg position (ST) during robot-assisted radical prostatectomy (RARP) poses a risk of increase in intraocular pressure (IOP) in men receiving robot-assisted radical prostatectomy (RARP). The aim of the study was to identify clinicopathological factors associated with increased IOP during RARP. METHODS: We prospectively studied 59 consecutive prostate cancer patients without glaucoma. IOP was measured at 6 predefined time points before, during and after the operation (T1 to T6). RESULTS: Compared with T1, IOP decreased after beginning of anesthesia(T2) (by - 6.5 mmHg, p < 0.05), and increased 1 h after induction of pneumoperitoneum in the steep Trendelenburg position (ST) (T3) (+ 7.3 mmHg, p < 0.05). IOP continued to increase until the end of ST (T4) (+ 10.2 mmHg, p < 0.05), and declined when the patient was returned to supine position under general anesthesia (T5) (T1: 20.0 and T5: 20.1 mmHg, p above 0.05). The console time affected the elevation of IOP in ST; IOP elevation during ST was more prominent in men with a console time of ≥4 h (n = 39) than in those with a console time of < 4 h (n = 19) (19.8 ± 6.3 and 15.4 ± 5.8 mmHg, respectively, p < 0.05). Of the 59 patients, 29 had a high baseline IOP (20.0 mmHg or higher), and their IOP elevated during ST was also reduced at T5 (T1: 22.6 and T5: 21.7 mmHg, p above 0.05). There were no postoperative ocular complications. CONCLUSIONS: Console time of < 4 h is important to prevent extreme elevation of IOP during RARP. Without long console time, RARP may be safely performed in those with relatively high baseline IOP.

Conservative management of bilateral traumatic testicular dislocation in a 10-year-old boy.

A 10-year-old boy fell from a one-meter-high Jacuzzi ladder in a hot spring facility, landing in a straddle position, and injured his perineum. He visited the emergency room of our hospital immediately after the injury. Magnetic resonance imaging (MRI) revealed a tear of the corpus spongiosum urethra, and compression due to a hematoma. With the hematoma spreading to the scrotum, the testes became inverted and dislocated to the inguinal region on both sides. Without surgery or interventions, the testes descended into the scrotum on the third day after the injury before fibrillation and scarring began. Testicular dislocation by injury is rare and encountered exclusively in children. It is generally treated with surgery to retain testicular function. We selected conservative management, as our patient had a closed injury without testicular torsion, and the testicular dislocation was associated with compression by hematoma, which could possibly recover with regression of the hematoma.

[A case of prostate cancer presenting as extensive abdominal metastasis].

A 73-year-old man was admitted to our hospital with a chief complaint of hematemesis. Two years before admission, adenocarcinoma of unknown origin was diagnosed. Since then, the patient had been taking TS-1 (pramoxine hydrochloride) medication, which caused gastroduodenal mucosal damage. A large abdominal tumor and elevated prostate specific antigen (PSA) level of 13,190 ng/ml, caused by this damage, were detected. Extensive abdominal metastasis of prostate cancer was diagnosed and combined androgen blockade was initiated. After 3 months, the PSA level decreased to 4.4 ng/ml and the abdominal tumor shrunk significantly. Physicians should keep in mind prostate cancer in the differential diagnosis of unexplained adenocarcinoma.