Expressions of PD-L1 and Nectin-4 in urothelial cancer patients treated with pembrolizumab

ObjectivesRecently, the standard of care for advanced urothelial cancer (UC) has been changed by developing immune-checkpoint inhibitors (ICIs). However, its response rate is limited to 20–30%. The identification of biomarkers to predict the therapeutic effects of ICIs is urgently needed. The present study explored the association between immunohistochemical biomarkers and clinical outcomes in UC patients treated with pembrolizumab.Patients and methodsA total of 85 patients with UC who received pembrolizumab after chemotherapy from January 2018 to May 2020 were retrospectively reviewed. Tumor tissues were obtained for immunohistochemical study from 47 out of 85 patients. The protein expressions of PD-L1, WT1, Nectin-4, CD4, CD8, Foxp3, and CD68 in tumor cells and/or tumor infiltrating lymphocytes were immunohistochemically examined. The associations between protein expressions and overall survival (OS), progression-free survival (PFS), and disease control rate (DCR) were statistically analyzed.ResultsPatients with positive PD-L1 in tumor cells showed significantly worse OS (Log-rank test: HR 5.146, p = 0.001, Cox regression analysis: HR 4.331, p = 0.014) and PFS (Log-rank test: HR 3.31. p = 0.022), along with significantly lower DCR (14.3%) compared to the PD-L1 negative patients (67.5%). In addition, patients with strong expression of Nectin-4 in tumor cells showed significantly higher DCR (100%) than the other patients (50%).ConclusionPD-L1 expression in tumor cells was associated with poor prognosis (OS and PFS) and low DCR. Interestingly, the strong expression of Nectin-4 was correlated with high DCR. PD-L1 and Nectin-4 expression in tumor cells could be prognostic biomarkers useful for pembrolizumab in patients with advanced UC.

Expressions of PD-L1 and Nectin-4 in urothelial cancer patients treated with pembrolizumab.

OBJECTIVES: Recently, the standard of care for advanced urothelial cancer (UC) has been changed by developing immune-checkpoint inhibitors (ICIs). However, its response rate is limited to 20-30%. The identification of biomarkers to predict the therapeutic effects of ICIs is urgently needed. The present study explored the association between immunohistochemical biomarkers and clinical outcomes in UC patients treated with pembrolizumab. PATIENTS AND METHODS: A total of 85 patients with UC who received pembrolizumab after chemotherapy from January 2018 to May 2020 were retrospectively reviewed. Tumor tissues were obtained for immunohistochemical study from 47 out of 85 patients. The protein expressions of PD-L1, WT1, Nectin-4, CD4, CD8, Foxp3, and CD68 in tumor cells and/or tumor infiltrating lymphocytes were immunohistochemically examined. The associations between protein expressions and overall survival (OS), progression-free survival (PFS), and disease control rate (DCR) were statistically analyzed. RESULTS: Patients with positive PD-L1 in tumor cells showed significantly worse OS (Log-rank test: HR 5.146, p = 0.001, Cox regression analysis: HR 4.331, p = 0.014) and PFS (Log-rank test: HR 3.31. p = 0.022), along with significantly lower DCR (14.3%) compared to the PD-L1 negative patients (67.5%). In addition, patients with strong expression of Nectin-4 in tumor cells showed significantly higher DCR (100%) than the other patients (50%). CONCLUSION: PD-L1 expression in tumor cells was associated with poor prognosis (OS and PFS) and low DCR. Interestingly, the strong expression of Nectin-4 was correlated with high DCR. PD-L1 and Nectin-4 expression in tumor cells could be prognostic biomarkers useful for pembrolizumab in patients with advanced UC.

Flow cytometry as a diagnostic method for colorectal cancer.

Intraoperative histopathological investigation plays an important role during surgery. Since the pathologist performs a diagnosis with a limited level of specimen, it may sometimes be difficult to reach a correct diagnosis. To improve the accuracy of the diagnosis, quantitative data from the whole specimen are helpful. It said that the detection capability for DNA aneuploidy (aneuploidy) is low for solid cancer compared with hematopoietic organ cancer. A new method that includes fresh tissue is introduced, the histogram from cancer tissue (cancer) and normal tissue (normal) is compared, new classification criteria are introduced, the Fast Fourier Transform (FFT) pattern (FFT pattern) obtained from FFT on the histogram is analyzed, and the area under the FFT pattern of the histogram (AUC) is compared. This method, named the "FFT-AUC method", which includes comparisons of AUC and the FFT pattern, shows good results.

New automatic cell isolation system for flow cytometry: cell isolation unit and staining reagent kit.

Flow cytometry is well-known cell analysis method and useful to gain quantitative information from cells in blood, however, it is not widely used for solid tissues in clinical settings. This is partly because it takes a long time to prepare samples and the operation can be complicated. To resolve these problems, we developed a new automatic cell isolation system which consists of cell isolation unit and staining reagent kit specialized for flow cytometry. With this new system, cell isolation can be done more rapidly and easily. By using this method, we could determine optimum condition to disintegrate porcine colon tissue and stain cells stably in 6 minutes. This result indicates that our method can provide analysis data within 10 minutes. We also evaluated our method in colorectal cancer patients, and the result was promising. All the data suggests that this method can support and facilitate rapid diagnosis.

Classification of the distribution of cavernous nerve fibers around the prostate by intraoperative electrical stimulation during laparoscopic radical prostatectomy.

We investigated the distribution of cavernous nerve (CN) fibers around the prostate by electrical nerve stimulation during laparoscopic radical prostatectomy to classify the distribution of the CN fibers. Electrical stimulation was performed on 30 consecutive patients with localized prostate cancer; middle of the neurovascular bundle (NVB, point A), base of the NVB (point B), the rectal wall 1 cm posterolateral to the NVB (point C) and the lateral aspect of the prostate (point D). We measured the intraurethral pressure at the midportion to detect the changes in intracavernosal pressure. The mean maximum changes were 10.5 ± 7.9, 11.6 ± 8.8, 9.6 ± 7.4 and 6.7 ± 7.0 cm H(2)O at points A, B, C and D, respectively. The patterns of CN fiber distribution were divided into four groups: type 1 (23%), the bundle corresponding to the NVB; type 2 (7%), the bundle from the rectal wall to the prostate; type 3 (27%), the plate including NVB and posterolateral to NVB; and type 4 (43%), the plate between the rectal wall posterolateral to the NVB and the lateral aspect of the prostate. Distribution of the CNs in a bundle-like formation was considered to account for 30%, whereas a plate-like formation accounted for 70%. Understanding these four patterns of CN fiber distribution should facilitate accurate CN-sparing radical prostatectomy.

[Prospects for molecular research in urological oncology: gene therapy].

The recent great advances in genetic engineering are now making possible the identification and isolation of the trigger genes of many hereditary illnesses, and the clarification of the relevant molecular mechanisms. The idea that if the genetic abnormalities responsible for illness could be established at a DNA level, treatment at the genetic level repairing damaged genes or supplying absent ones would also be possible was the incentive for the recent boom in gene therapy. Clinical research into gene therapy began in 1990 and currently over 3,000 patient cases are being studied. Some 70% of these are cancer patients. This is not simply because such patients are relatively numerous, but is also a sign of the wish, held earnestly by many researchers and clinicians as well as cancer patients and their families, to at last overcome this intractable disease. Gene therapy, so far conducted mainly in the United States, has hitherto not lived up to initial expectations in its concrete results. The reason for this results mainly in technical factors, such as the rate of success in implanting genes into target cells, the rate of successful expression of the implanted genes, and the successful achievement of specific expression at the target site. Gene therapy in the form of clinical research into renal cancer and lung cancer is now under way in Japan. It is too early at this stage to evaluate this work, but the present paper takes this opportunity to give an outline of gene therapy, and to examine its current state, future prospects and problem areas with particular reference to cancer.

p53 adenoviral vector (Ad-CMV-p53) induced prostatic growth inhibition of primary cultures of human prostate and an experimental rat model.

BACKGROUND: Benign prostatic hyperplasia (BPH) is the most common proliferative disease affecting men. Numerous minimally invasive technologies are being developed or are currently in use to obviate the need for transurethral surgery. The goal of the present study was to develop a novel molecular based approach for the treatment of BPH using recombinant p53 adenoviral vector. The over-expression of wt-p53 can cause cell apoptosis or cell growth arrest, thus preventing the uncontrolled cell proliferation underlying BPH pathophysiology. METHODS: Ad-CMV-p53, a replication-deficient recombinant adenovirus containing cytomegalovirus promoter driving p53 gene, was used. Human prostate stromal (PS) cells were evaluated for apoptosis (TUNEL assay), mRNA levels of key cell cycle regulators influencing apoptosis (p-53, Bax and Bcl-2) using quantitative RT-PCR and cytotoxicity after Ad-CMV-p53. Ad-CMV-p53 was unilaterally injected into rat ventral prostates and growth inhibition was measured by prostate weight 3 weeks after injection. RESULTS: In vitro exposure to Ad-CMV-p53 significantly inhibited the proliferation of PS cells, induced mRNA over-expression of both wt-p53 and Bax, and increased the proportion of apoptotic cells. A 30% decrease in average prostate weight was demonstrated in rodents after Ad-CMV-p53 injection. CONCLUSIONS: The results suggest that further investigation of molecular gene therapy with recombinant wt-p53 adenovirus for the treatment of BPH is warranted.