FXYD3: A Promising Biomarker for Urothelial Carcinoma

Applications of Biosensors in Bladder Cancer

Bladder cancer (BC) is the tenth most common cancer globally, predominantly affecting men. Early detection and treatment are crucial due to high recurrence rates and poor prognosis for advanced stages. Traditional diagnostic methods like cystoscopy and imaging have limitations, leading to the exploration of noninvasive methods such as liquid biopsy. This review highlights the application of biosensors in BC, including electrochemical and optical sensors for detecting tumor markers like proteins, nucleic acids, and other biomolecules, noting their clinical relevance. Emerging therapeutic approaches, such as antibody-drug conjugates, targeted therapy, immunotherapy, and gene therapy, are also explored, the role of biosensors in detecting corresponding biomarkers to guide these treatments is examined. Finally, the review addresses the current challenges and future directions for biosensor applications in BC, highlighting the need for large-scale clinical trials and the integration of advanced technologies like deep learning to enhance diagnostic accuracy and treatment efficacy.

Next Generation of Ovarian Cancer Detection Using Aptamers

Ovarian cancer is among the seven most common types of cancer in women, being the most fatal gynecological tumor, due to the difficulty of detection in early stages. Aptamers are important tools to improve tumor diagnosis through the recognition of specific molecules produced by tumors. Here, aptamers and their potential targets in ovarian cancer cells were analyzed by in silico approaches. Specific aptamers were selected by the Cell-SELEX method using Caov-3 and OvCar-3 cells. The five most frequent aptamers obtained from the last round of selection were computationally modeled. The potential targets for those aptamers in cells were proposed by analyzing proteomic data available for the Caov-3 and OvCar-3 cell lines. Overexpressed proteins for each cell were characterized as to their three-dimensional model, cell location, and electrostatic potential. As a result, four specific aptamers for ovarian tumors were selected: AptaC2, AptaC4, AptaO1, and AptaO2. Potential targets were identified for each aptamer through Molecular Docking, and the best complexes were AptaC2-FXYD3, AptaC4-ALPP, AptaO1-TSPAN15, and AptaO2-TSPAN15. In addition, AptaC2 and AptaO1 could detect different stages and subtypes of ovarian cancer tissue samples. The application of this technology makes it possible to propose new molecular biomarkers for the differential diagnosis of epithelial ovarian cancer.

The distinguishing electrical properties of cancer cells

In recent decades, medical research has been primarily focused on the inherited aspect of cancers, despite the reality that only 5-10% of tumours discovered are derived from genetic causes. Cancer is a broad term, and therefore it is inaccurate to address it as a purely genetic disease. Understanding cancer cells' behaviour is the first step in countering them. Behind the scenes, there is a complicated network of environmental factors, DNA errors, metabolic shifts, and electrostatic alterations that build over time and lead to the illness's development. This latter aspect has been analyzed in previous studies, but how the different electrical changes integrate and affect each other is rarely examined. Every cell in the human body possesses electrical properties that are essential for proper behaviour both within and outside of the cell itself. It is not yet clear whether these changes correlate with cell mutation in cancer cells, or only with their subsequent development. Either way, these aspects merit further investigation, especially with regards to their causes and consequences. Trying to block changes at various levels of occurrence or assisting in their prevention could be the key to stopping cells from becoming cancerous. Therefore, a comprehensive understanding of the current knowledge regarding the electrical landscape of cells is much needed. We review four essential electrical characteristics of cells, providing a deep understanding of the electrostatic changes in cancer cells compared to their normal counterparts. In particular, we provide an overview of intracellular and extracellular pH modifications, differences in ionic concentrations in the cytoplasm, transmembrane potential variations, and changes within mitochondria. New therapies targeting or exploiting the electrical properties of cells are developed and tested every year, such as pH-dependent carriers and tumour-treating fields. A brief section regarding the state-of-the-art of these therapies can be found at the end of this review. Finally, we highlight how these alterations integrate and potentially yield indications of cells' malignancy or metastatic index.

The comprehensive and systematic identification of BLCA-specific SF-regulated, survival-related AS events

Bladder urothelial carcinoma (BLCA) is a complex disease with high morbidity and mortality. Changes in alternative splicing (AS) and splicing factor (SF) can affect gene expression, thus playing an essential role in tumorigenesis. This study downloaded 412 patients' clinical information and 433 samples of transcriptome profiling data from TCGA. And we collected 48 AS signatures from SpliceSeq. LASSO and Cox analyses were used for identifying survival-related AS events in BLCA. Finally, 1,645 OS-related AS events in 1,129 genes were validated by Kaplan-Meier (KM) survival analysis, ROC analysis, risk curve analysis, and independent prognostic analysis. Finally, our survey provides an AS-SF regulation network consisting of five SFs and 46 AS events. In the end, we profiled genes that AS occurred in pan-cancer and five SFs' expression in tumor and normal samples in BLCA. We selected CLIP-seq data for validation the interaction regulated by RBP. Our study paves the way for potential therapeutic targets of BLCA.

Na+/K+-ATPase Revisited: On Its Mechanism of Action, Role in Cancer, and Activity Modulation

Maintenance of Na⁺ and K⁺ gradients across the cell plasma membrane is an essential process for mammalian cell survival. An enzyme responsible for this process, sodium-potassium ATPase (NKA), has been currently extensively studied as a potential anticancer target, especially in lung cancer and glioblastoma. To date, many NKA inhibitors, mainly of natural origin from the family of cardiac steroids (CSs), have been reported and extensively studied. Interestingly, upon CS binding to NKA at nontoxic doses, the role of NKA as a receptor is activated and intracellular signaling is triggered, upon which cancer cell death occurs, which lies in the expression of different NKA isoforms than in healthy cells. Two major CSs, digoxin and digitoxin, originally used for the treatment of cardiac arrhythmias, are also being tested for another indication—cancer. Such drug repositioning has a big advantage in smoother approval processes. Besides this, novel CS derivatives with improved performance are being developed and evaluated in combination therapy. This article deals with the NKA structure, mechanism of action, activity modulation, and its most important inhibitors, some of which could serve not only as a powerful tool to combat cancer, but also help to decipher the so-far poorly understood NKA regulation.

Molecular Characterization of Upper Tract Urothelial Carcinoma in the Era of Next-generation Sequencing: A Systematic Review of the Current Literature

CONTEXT

While upper tract urothelial carcinoma (UTUC) share histological appearance with bladder cancer (BC), the former has differences in etiology and clinical phenotype consistent with characteristic molecular alterations.

OBJECTIVE

To systematically evaluate current genomic sequencing and proteomic data examining molecular alterations in UTUC.

EVIDENCE ACQUISITION

A systematic review using PubMed, Scopus, and Web of Science was performed in December 2019 according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement.

EVIDENCE SYNTHESIS

A total of 46 publications were selected for inclusion in this report, including 13 studies assessing genome-wide alterations, 18 studies assessing gene expression or microRNA expression profiles, three studies assessing proteomics, one study assessing genome-wide DNA methylation, and 14 studies evaluating distinct pathway alteration patterns. Differences between sporadic and hereditary UTUC, and between UTUC and BC, as well as molecular profiles associated with exposure to aristolochic acid are highlighted. Molecular pathways relevant to UTUC biology, such as alterations in FGFR3, TP53, or microsatellite instability, are discussed. Our findings are limited by tumor and patient heterogeneity and different platforms used in the studies.

CONCLUSIONS

Molecular events in UTUC and BC can be shared or distinct. Consequently, molecular subtypes differ according to location. Further work is needed to define the epigenomic and proteomic features of UTUC, and understand the mechanisms by which they shape the clinical behavior of UTUC.

PATIENT SUMMARY

We report the current data on the molecular alterations specific to upper tract urothelial carcinoma (UTUC), resulting from novel genomic and proteomic technologies. Although UTUC biology is comparable with that of bladder cancer, the rates and UTUC-enriched alterations support its uniqueness and the need for precision medicine strategies for this rare tumor type.

Instrument-Free Detection of FXYD3 Using Vial-Based Immunosensor for Earlier and Faster Urothelial Carcinoma Diagnosis

The incidence and 5 year recurrence rate of urothelial carcinomas (UCs), including UC of the bladder (UCB) and upper urinary tract UC (UTUC), have increased annually. There is a great need for a simple and fast point-of-care (POC) test for early diagnosis and amelioration in the survival rate. We present a POC test comprising a new vial-immunosensor, nanoenzyme, and iPhone 7 plus, which detects and quantifies the new biomarker FXYD domain-containing ion transport regulator 3 (FXYD3) in human urine for specific UC screening, tumor-grade classification, and postoperative monitoring by the grayscale value of the photograph taken. The performance of the proposed POC test was then verified using urine from 4 healthy people, 40 UCB patients (10 patients were low-grade and 30 patients were high-grade), and 13 UTUC patients (2 patients were low-grade and 11 patients were high-grade), confirming the accuracy and specificity by comparing the results with those obtained by enzyme-linked immunosorbent assay (ELISA). Moreover, we also designed a correction method that can make the grayscale values calculated by different smartphones close to the values calculated by iPhone 7 plus, resulting in the POC test enabling simple, fast, universal, and portable testing, data storage, and sharing for personal UCs screening and postoperative monitoring.

Molecular lymph node staging for bladder cancer patients undergoing radical cystectomy with pelvic lymph node dissection

OBJECTIVE

Presence of lymph node (LN) metastasis in bladder cancer (BCa) is a main risk factor for tumor recurrence after radical cystectomy (RC). Molecular analysis facilitates detection of small-volume LN metastases with higher sensitivity than standard histopathology. The aim of the present study was to establish molecular LN analysis in BCa patients undergoing RC with lymph node dissection (LND) and to determine its ability to predict tumor recurrence.

PATIENTS AND METHODS

Five transcripts with overexpression in BCa (FXYD3, KRT17, KRT20, SPINK1, UPKII) were evaluated for molecular LN analysis. We included 76 BCa patients from the prospective, randomized surgical phase-III trial (LEA AUO AB 25/02, NCT01215071) investigating extended vs. limited LND at RC. The primary endpoint was recurrence-free survival (RFS). As control, 136 LNs from 45 patients without BCa were analyzed to determine a threshold for pathologic gene expression.

RESULTS

About 1,319 LNs were investigated with molecular and histopathologic examination. Histopathology detected 39 LN metastases in 17 (22%) patients. Of the tested genes FXYD3 performed best and classified all pN+-patients correctly as node-positive (pN+/molN+). In addition, FXYD3 reclassified 43 histopathologic negative LNs and 7 (9%) pN0-patients as molecular node-positive (pN0/molN+). Molecular and histopathologic LN status (pN0/molN0 vs. pN0/molN+ vs. pN+/molN+) was significantly associated with locally advanced disease (P = 0.006) and poor RFS (P < 0.001). Median RFS was not reached in LN-negative patients (pN0/molN0), 45 months (95%CI 8-83) in exclusively molecular positive patients (pN0/molN+) and 9 months (95%CI 5-13) in patients with histopathologic and molecular positive LNs (pN+/molN+).

CONCLUSIONS

Molecular LN analysis with FXYD3 identified additional LN metastases in histopathologic negative LNs and identified patients with elevated risk of tumor recurrence after RC. Thus, molecular LN analysis improves LN staging and might serve as a tool to guide adjuvant treatment.

Recent advances in upper tract urothelial carcinomas: From bench to clinics

Urothelial carcinoma in the upper tract is rare and often discussed separately. Many established risk factors were identified for the disease, including genetic and external risk factors. Radiographic survey, endoscopic examination and urine cytology remained the most important diagnostic modalities. In localized upper tract urothelial carcinomas, radical nephroureterectomy with bladder cuff excision are the gold standard for large, high-grade and suspected invasive tumors of the renal pelvis and proximal ureter, whereas kidney-sparing surgeries should be considered in patients with low-risk disease. Advances in technology have given endoscopic surgery an important role, not only in diagnosis, but also in treatment. Although platinum-based combination chemotherapy is efficacious in advanced or metastatic disease, current established chemotherapy regimens are toxic and lack a sustained response. Immune checkpoint inhibitors have led to a new era of treatment for advanced or metastatic urothelial carcinomas. The remarkable results achieved thus far show that immunotherapy will likely be the future treatment paradigm. The combination of immune checkpoint inhibitors and other agents is another inspiring avenue to explore that could benefit even more patients. With respect to the high incidence rate and different clinical appearance of upper tract urothelial carcinomas in Taiwan, a possible correlation exists between exposure to certain external risk factors, such as arsenic in drinking water and aristolochic acid in Chinese herbal medicine. As more gene sequencing differences between upper tract urothelial carcinomas and various disease causes are detailed, this has warranted the era of individualized screening and treatment for the disease.

Ion channels expression and function are strongly modified in solid tumors and vascular malformations

Background

Several cellular functions relate to ion-channels activity. Physiologically relevant chains of events leading to angiogenesis, cell cycle and different forms of cell death, require transmembrane voltage control. We hypothesized that the unordered angiogenesis occurring in solid cancers and vascular malformations might associate, at least in part, to ion-transport alteration.

Methods

The expression level of several ion-channels was analyzed in human solid tumor biopsies. Expression of 90 genes coding for ion-channels related proteins was investigated within the Oncomine database, in 25 independent patients-datasets referring to five histologically-different solid tumors (namely, bladder cancer, glioblastoma, melanoma, breast invasive-ductal cancer, lung carcinoma), in a total of 3673 patients (674 control-samples and 2999 cancer-samples). Furthermore, the ion-channel activity was directly assessed by measuring in vivo the electrical sympathetic skin responses (SSR) on the skin of 14 patients affected by the flat port-wine stains vascular malformation, i.e., a non-tumor vascular malformation clinical model.

Results

Several ion-channels showed significantly increased expression in tumors (p < 0.0005); nine genes (namely, CACNA1D, FXYD3, FXYD5, HTR3A, KCNE3, KCNE4, KCNN4, CLIC1, TRPM3) showed such significant modification in at least half of datasets investigated for each cancer type. Moreover, in vivo analyses in flat port-wine stains patients showed a significantly reduced SSR in the affected skin as compared to the contralateral healthy skin (p < 0.05), in both latency and amplitude measurements.

Conclusions

All together these data identify ion-channel genes showing significantly modified expression in different tumors and cancer-vessels, and indicate a relevant electrophysiological alteration in human vascular malformations. Such data suggest a possible role and a potential diagnostic application of the ion–electron transport in vascular disorders underlying tumor neo-angiogenesis and vascular malformations.

External validation of FXYD3 and KRT20 as predictive biomarkers for the presence of micrometastasis in muscle invasive bladder cancer lymph nodes

INTRODUCTION

Recent studies have proposed that FXYD3 and KRT20 mRNA quantified by quantitative reverse transcription polymerase chain reaction (qRT-PCR) in paraffin could be biomarkers to detect lymph nodes with micrometastases that avoid detection by conventional analysis with hematoxylin-eosin (HE). A validation study was conducted on the lymph nodes of patients who underwent radical cystectomy.

OBJECTIVE

To classify the adenopathic state of a sample of patients who underwent cystectomy, based on the lymph node expression of FXYD3 and KRT20. The secondary objective was to assess whether there is a differential oncologic evolution for the patients, depending on the lymph node expression of these proteins.

MATERIAL AND METHOD

The study included lymph nodes from 64 patients who underwent cystectomy for infiltrating bladder tumor: The model was developed using metastatic lymph nodes from 15 patients and lymph nodes from 4 patients with no known tumor. Genetic expression was measured using real-time qRT-PCR. We calculated (using qRT-PCR) the median expression of FXYD3 and KRT20 mRNA in the lymph node tissue. We then analyzed the receiver operating characteristic (ROC) curves, according to the function y=0.1400+0.250FXYD3-2.532. The cutoff was established using an ROC curve. The formula was applied to the remaining lymph node tissue, based on the previously established cutoff. The sample was classified into 4 subgroups: HE- qRT-PCR-, HE- qRT-PCR+, HE+ qRT-PCR+ y HE+, qRT-PCR-. A descriptive, comparative analysis was performed, as well as a metastatic progression-free survival analysis, calculating the Kaplan and Meyer curves for the 3 established subgroups. The test results were considered statistically significant at P<.05.

RESULTS

Using qRT-PCR, we verified that there were differences in the median expression of FXYD3 (P=.05) and KRT20 (P=.009) between the lymph node tissues of patients with benign prostate hyperplasia and those of patients with lymph node metastasis. A cutoff was assigned to 0.377. The sample was classified as follows: 37.5% of the patients were pN0 by HE and pN0 by qRT-PCR (-HE -qRT-PCR), 39.1% were pN0 by HE but metastatic by qRT-PCR (-HE +qRT-PCR), and 15 patients (23.4%) were metastatic by both techniques (+HE +qRT-PCR). The Kaplan and Meyer curves showed poorer metastatic progression-free survival for the patients who were +HE and +qRT-PCR than for the other subgroups, with no significant differences between -HE +qRT-PCR and -HE -qRT-PCR.

CONCLUSIONS

According to our results, 39.1% of the patients with infiltrating vesical tumors overexpressed the FXYD3 and KRT20 biomarkers and were N0 by HE. We observed no differential clinical behavior among the patients who underwent cystectomy according to their expression of FXYD3 and KRT20 when they were N0 by HE.

Gluco-incretins regulate beta-cell glucose competence by epigenetic silencing of Fxyd3 expression

BACKGROUND/AIMS

Gluco-incretin hormones increase the glucose competence of pancreatic beta-cells by incompletely characterized mechanisms.

METHODS

We searched for genes that were differentially expressed in islets from control and Glp1r-/-; Gipr-/- (dKO) mice, which show reduced glucose competence. Overexpression and knockdown studies; insulin secretion analysis; analysis of gene expression in islets from control and diabetic mice and humans as well as gene methylation and transcriptional analysis were performed.

RESULTS

Fxyd3 was the most up-regulated gene in glucose incompetent islets from dKO mice. When overexpressed in beta-cells Fxyd3 reduced glucose-induced insulin secretion by acting downstream of plasma membrane depolarization and Ca++ influx. Fxyd3 expression was not acutely regulated by cAMP raising agents in either control or dKO adult islets. Instead, expression of Fxyd3 was controlled by methylation of CpGs present in its proximal promoter region. Increased promoter methylation reduced Fxyd3 transcription as assessed by lower abundance of H3K4me3 at the transcriptional start site and in transcription reporter assays. This epigenetic imprinting was initiated perinatally and fully established in adult islets. Glucose incompetent islets from diabetic mice and humans showed increased expression of Fxyd3 and reduced promoter methylation.

CONCLUSIONS/INTERPRETATION

Because gluco-incretin secretion depends on feeding the epigenetic regulation of Fxyd3 expression may link nutrition in early life to establishment of adult beta-cell glucose competence; this epigenetic control is, however, lost in diabetes possibly as a result of gluco-incretin resistance and/or de-differentiation of beta-cells that are associated with the development of type 2 diabetes.

Accurate detection of upper tract urothelial carcinoma in tissue and urine by means of quantitative GDF15, TMEFF2 and VIM promoter methylation

AIM OF THE STUDY

Upper tract urothelial carcinoma (UTUC) accounts for 5-10% of all urothelial tumours. It is mostly diagnosed at advanced stages, entailing a worse prognosis, owing to the lack of early and specific symptoms as well as of effective diagnostic tools. We previously identified a panel of epigenetic biomarkers (GDF15, TMEFF2 and VIM promoter methylation) that accurately identifies bladder cancer in urine. Herein, we assessed the performance of the same panel for UTUC detection and prognosis, in tissue and urine.

MATERIAL AND METHODS

Methylation levels of reference and target genes were determined using real-time quantitative methylation-specific polymerase chain reaction (MSP) in bisulphite-modified DNA of 57 UTUC tissues, 36 normal upper tract urothelium (NUTUs), 22 urines from UTUC suspects and 20 urines from controls. Receiver operator characteristics (ROC)-curve analysis was performed to determine the performance of the biomarker panel and survival analyses were conducted to evaluate their prognostic value.

RESULTS

Methylation levels of GDF15, TMEFF2 and VIM were significantly higher in UTUC compared to NUTUs (P=0.022; P<0.001; P<0.001, respectively). The panel accurately identified UTUC with 100% and 91% sensitivity, corresponding to an area under the curve of 1.000 and 0.923 in tissue and urines, respectively, with 100% specificity. Low VIM promoter methylation levels independently predicted poor disease-specific survival.

CONCLUSIONS

GDF15, TMEFF2 and VIM promoter methylation allows for accurate identification of UTUC, in tissue and urine and VIM methylation provides relevant prognostic information, especially in high-stage disease. This assay may improve the clinical management of UTUC patients.

Overexpression of FXYD-3 is involved in the tumorigenesis and development of esophageal squamous cell carcinoma

Objective. To investigate the association of FXYD-3 expression with clinicopathological variables and PINCH in patients with ESCC. Patients and Methods. Expression of FXYD-3 protein was immunohistochemically examined in normal esophageal mucous (n = 20) and ESCC (n = 64). Results. Expression of FXYD-3 in the cytoplasm markedly increased from normal esophageal epithelial cells to primary ESCC (P = 0.001). The expression of FXYD-3 was correlated with TNM stages and depth of tumor invasion. Furthermore, the cases with lymph node metastasis tended to show a higher frequency of positive expression than those without metastasis (P = 0.086), and FXYD-3 expression tended to be positively related to the expression of PINCH (P = 0.063). Moreover, the cases positive for both proteins had the highest frequency of lymph node metastasis (P = 0.001). However, FXYD-3 expression was not correlated with patient's gender (P = 0.847), age (P = 0.876), tumor location (P = 0.279), size (P = 0.771), grade of differentiation (P = 0.279), and survival (P = 0.113). Conclusion. Overexpression of FXYD-3 in the cytoplasm may play an important role in the tumorigenesis and development in the human ESCC, particularly in combination with PINCH expression.

Tissue-based proteomics reveals FXYD3, S100A11 and GSTM3 as novel markers for regional lymph node metastasis in colon cancer

Regional lymph node metastasis negatively affects prognosis in colon cancer patients. The molecular processes leading to regional lymph node metastasis are only partially understood and proteomic markers for metastasis are still scarce. Therefore, a tissue-based proteomic approach was undertaken for identifying proteins associated with regional lymph node metastasis. Two complementary tissue-based proteomic methods have been employed. MALDI imaging was used for identifying small proteins (≤25 kDa) in situ and label-free quantitative proteomics was used for identifying larger proteins. A tissue cohort comprising primary colon tumours without metastasis (UICC II, pN0, n = 21) and with lymph node metastasis (UICC III, pN2, n = 33) was analysed. Subsequent validation of identified proteins was done by immunohistochemical staining on an independent tissue cohort consisting of primary colon tumour specimens (n = 168). MALDI imaging yielded ten discriminating m/z species, and label-free quantitative proteomics 28 proteins. Two MALDI imaging-derived candidate proteins (FXYD3 and S100A11) and one from the label-free quantitative proteomics (GSTM3) were validated on the independent tissue cohort. All three markers correlated significantly with regional lymph node metastasis: FXYD3 (p = 0.0110), S100A11 (p = 0.0071), and GSTM3 (p = 0.0173). FXYD3 and S100A11 were more highly expressed in UICC II patient tumour tissues. GSTM3 was more highly expressed in UICC III patient tumour tissues. By our tissue-based proteomic approach, we could identify a large panel of proteins which are associated with regional lymph node metastasis and which have not been described so far. Here we show that novel markers for regional lymph metastasis can be identified by MALDI imaging or label-free quantitative proteomics and subsequently validated on an independent tissue cohort.

Preliminary study of thyroid and colon cancers-associated antigens and their cognate autoantibodies as potential cancer biomarkers

BACKGROUND

Autoantibodies, which are produced against tumor-associated antigens, are potential tumor markers and attract a growing interest for cancer detection, differential diagnostics and prognosis.

OBJECTIVE

To evaluate the diagnostic significance of 40 antigens identified by immunoscreening of cDNA libraries from thyroid and colon cancers by allogenic screening with different tumor types patients' sera.

METHOD

Plaque-spot serological assay.

RESULTS

Increased frequency of antibody response in sera of cancer patients compared with that of healthy donors was shown toward 14 antigens, 8 of which (CG016, BTN3A3, FKBP4, XRCC4, TSGA2, ACTR1A, FXYD3 and CTSH) have revealed exclusively cancer-related serological profile.

CONCLUSION

Allogenic screening of 40 SEREX-antigens with sera from cancer patients and healthy donors allowed us to reveal 14 antigens with potential diagnostic significance. These antigens and their cognate autoantibodies could be considered as valuable targets for further analysis as potential cancer biomarkers.