Evaluation of hTERT, KRT7, and survivin in urine for noninvasive detection of bladder cancer using real-time PCR

Atypical cells in urine sediment: a novel biomarker for early detection of bladder cancer

OBJECTIVES

Atypical cells (Atyp.C), as a new parameter determined by an automated urine analyzer, can be suspected of being malignant tumor cells. We evaluated the extent to which the Atyp.C can predict the existence of malignant tumor cells.

METHODS

A total of 3,315 patients (1,751 in the training cohort and 1,564 in the testing cohort) were recruited and divided into five groups, namely, primary bladder cancer (BCa), recurrent BCa, post-treatment monitoring of BCa, other urological tumors, and controls. Urine Atyp. C, bacteria, white blood cell, and red blood cell were measured by a Sysmex UF-5000 analyzer. We compared the Atyp.C values across the different groups, sexes, and tumor stages. The diagnostic performance of Atyp.C alone and in combination with other parameters for detecting BCa was evaluated using receiver operating characteristic (ROC) curve analysis.

RESULTS

The Atyp.C value of the primary BCa group was significantly higher than that in the other groups, except recurrent BCa group. The Atyp.C value was closely related to tumor staging. Atyp.C combined with bacteria had the highest diagnostic performance for primary BCa [training cohort AUC: 0.781 (95 % CI: 0.761-0.801); testing cohort AUC: 0.826 (95 % CI: 0.806-0.845)]. The AUC value of diagnosed recurrent BCa by Atyp.C plus bacteria for the training cohort was 0.784 (95 % CI: 0.762-0.804).

CONCLUSIONS

Atyp.C was high in primary BCa patients and the combination of bacteria and Atyp.C showed high predictive value for primary BCa, suggesting that Atyp.C may be a useful objective indicator for the early detection of BCa.

Clinical significance of KRT7 in bladder cancer prognosis

BACKGROUND

Typically, the overexpressed keratin 7 (KRT7) is considered a validated therapeutic target and prognosis marker in bladder cancer. However, the crucial roles of KRT7 in the clinical prognosis and immune microenvironment in bladder cancer remain unclear.

METHODS

Initially, the expression levels of KRT7 in public databases were analyzed that is,Tumor Immune Estimation Resource (TIMER) 2.0 and Gene Expression Profiling Interactive Analysis (GEPIA). Further, the clinical tissue samples from patients (n = 10 pairs) were collected to confirm the expression trends of KRT7 and detected by immunohistochemistry (IHC) analysis. Meanwhile, the relationship between KRT7 and the prognosis of bladder cancer patients was analyzed by Kaplan-Meier plotter estimation and Cox regression analysis. Finally, TIMER 2.0 and IHC staining analyses were performed to calculate the infiltration abundances of three kinds of immune cells in eligible bladder tumor samples.

RESULTS

The TIMER 2.0 and GEPIA datasets suggested the differences in the expression levels of KRT7 in tumors, in which KRT7 was significantly upregulated in bladder cancer. The KRT7 expression was closely associated with patients' gender, tumor histologic subtypes, T status, and American Joint Committee on Cancer stages. Notably, the increased KRT7 indicated poor overall survival and disease-free survival rates. Moreover, KRT7 expression could be responsible for immune infiltration in the cancer microenvironment of the bladder. Finally, the high expression level of KRT7 increased the presence of regulatory T cells (Tregs) but reduced the infiltration of CD8+ T and natural killer cells.

CONCLUSION

KRT7 as a biomarker potentiated the prediction of bladder cancer prognosis and the immune microenvironment.

The long non-coding RNA keratin-7 antisense acts as a new tumor suppressor to inhibit tumorigenesis and enhance apoptosis in lung and breast cancers

Expression of the long non-coding RNA (lncRNA) keratin-7 antisense (KRT7-AS) is downregulated in various types of cancer; however, the impact of KRT7-AS deficiency on tumorigenesis and apoptosis is enigmatic. We aim to explore the influence of KRT7-AS in carcinogenesis and apoptosis. We found that KRT7-AS was deficient in breast and lung cancers, and low levels of KRT7-AS were a poor prognostic factor in breast cancer. Cellular studies showed that silencing of KRT7-AS in lung cancer cells increased oncogenic Keratin-7 levels and enhanced tumorigenesis, but diminished cancer apoptosis of the cancer cells; by contrast, overexpression of KRT7-AS inhibited lung cancer cell tumorigenesis. Additionally, KRT7-AS sensitized cancer cells to the anti-cancer drug cisplatin, consequently enhancing cancer cell apoptosis. In vivo, KRT7-AS overexpression significantly suppressed tumor growth in xenograft mice, while silencing of KRT7-AS promoted tumor growth. Mechanistically, KRT7-AS reduced the levels of oncogenic Keratin-7 and significantly elevated amounts of the key tumor suppressor PTEN in cancer cells through directly binding to PTEN protein via its core nucleic acid motif GGCAAUGGCGG. This inhibited the ubiquitination-proteasomal degradation of PTEN protein, therefore elevating PTEN levels in cancer cells. We also found that KRT7-AS gene transcription was driven by the transcription factor RXRα; intriguingly, the small molecule berberine enhanced KRT7-AS expression, reduced tumorigenesis, and promoted apoptosis of cancer cells. Collectively, KRT7-AS functions as a new tumor suppressor and an apoptosis enhancer in lung and breast cancers, and we unraveled that the RXRα-KRT7-AS-PTEN signaling axis controls carcinogenesis and apoptosis. Our findings highlight a tumor suppressive role of endogenous KRT7-AS in cancers and an important effect the RXRα-KRT7-AS-PTEN axis on control of cancer cell tumorigenesis and apoptosis, and offer a new platform for developing novel therapeutics against cancers.

Clinical application of the anti-human telomerase reverse transcriptase (hTERT) antibody (SCD-A7) immunocytochemistry in liquid-based urine cytology: A prospective, single institute study

OBJECTIVES

Urine cytology is the most widely used noninvasive screening tool for urothelial carcinoma diagnosis and surveillance. Although highly specific, urine cytology exhibits suboptimal sensitivity. This study aimed to determine whether hTERT immunocytochemistry (ICC) could be applicable as an ancillary test in routine cytology practice.

METHODS

A total of 561 urinary tract samples were initially screened in this study. All of them were prepared using SurePath liquid-based cytology (LBC), while additional LBC slides were made and subsequently used for hTERT (SCD-A7) ICC.

RESULTS

From the 561 samples screened, 337 were finally analyzed, all having an adequate cellularity and available follow-up histology. The hTERT ICC-positive rate was 95.9% (n = 208/217), 96% (n = 24/25), and 100% (n = 4/4) in cytology samples with high-grade urothelial carcinoma, carcinoma in situ, and low-grade urothelial carcinoma subsequent histology. Among the 64 atypical cytology cases histologically confirmed as urothelial carcinomas, 92.2% (n = 59/64) were immunoreactive to hTERT, whereas the two histologically benign cases were ICC-negative. 87/90 (96.7%) of the cytology cases confirmed to be benign in follow-up were hTERT-negative. The overall sensitivity and specificity of hTERT ICC were 96.3% and 98.8%, respectively (AUROC = 0.963; 95% CI = 0.960-0.967).

CONCLUSIONS

The hTERT ICC test exhibited consistent and intense staining in malignant urothelial cells, suggesting its value as an ancillary test in liquid-based urine cytology.

Inhibitor of apoptosis proteins as therapeutic targets in bladder cancer

Evasion from apoptosis is a hallmark of cancer. Inhibitor of apoptosis proteins (IAPs) contribute to this hallmark by suppressing the induction of cell death. IAPs were found to be overexpressed in cancerous tissues and to contribute to therapeutic resistance. The present review focuses on the IAP members cIAP1, cIAP2, XIAP, Survivin and Livin and their importance as potential therapeutic targets in bladder cancer.