Impact of CD44 expression on radiation response for bladder cancer

Silencing the Mitochondrial Gatekeeper VDAC1 as a Potential Treatment for Bladder Cancer

The strategy for treating bladder cancer (BC) depends on whether there is muscle invasion or not, with the latter mostly treated with intravesical therapy, such as with bacillus Calmette-Guérin (BCG). However, BCG treatment is unsuccessful in 70% of patients, who are then subjected to radical cystectomy. Although immune-checkpoint inhibitors have been approved as a second-line therapy for a subset of BC patients, these have failed to meet primary endpoints in clinical trials. Thus, it is crucial to find a new treatment. The mitochondrial gatekeeper protein, the voltage-dependent anion channel 1 (VDAC1), mediates metabolic crosstalk between the mitochondria and cytosol and is involved in apoptosis. It is overexpressed in many cancer types, as shown here for BC, pointing to its significance in high-energy-demanding cancer cells. The BC cell lines UM-UC3 and HTB-5 express high VDAC1 levels compared to other cancer cell lines. VDAC1 silencing in these cells using siRNA that recognizes both human and mouse VDAC1 (si-m/hVDAC1-B) reduces cell viability, mitochondria membrane potential, and cellular ATP levels. Here, we used two BC mouse models: subcutaneous UM-UC3 cells and chemically induced BC using the carcinogen N-Butyl-N-(4-hydroxybutyl) nitrosamine (BBN). Subcutaneous UM-UC3-derived tumors treated with si-m/hVDAC1 showed inhibited tumor growth and reprogrammed metabolism, as reflected in the reduced expression of metabolism-related proteins, including Glut1, hexokinase, citrate synthase, complex-IV, and ATP synthase, suggesting reduced metabolic activity. Furthermore, si-m/hVDAC1-B reduced the expression levels of cancer-stem-cell-related proteins (cytokeratin-14, ALDH1a), modifying the tumor microenvironment, including decreased angiogenesis, extracellular matrix, tumor-associated macrophages, and inhibited epithelial-mesenchymal transition. The BBN-induced BC mouse model showed a clear carcinoma, with damaged bladder morphology and muscle-invasive tumors. Treatment with si-m/hVDAC1-B encapsulated in PLGA-PEI nanoparticles that were administered intravesically directly to the bladder showed a decreased tumor area and less bladder morphology destruction and muscle invasion. Overall, the obtained results point to the potential of si-m/hVDAC1-B as a possible therapeutic tool for treating bladder cancer.

Potential Role of Lymphocyte CD44 in Determining Treatment Selection Between Stereotactic Body Radiation Therapy and Surgery for Early-Stage Non-Small Cell Lung Cancer

PURPOSE

Stereotactic body radiation therapy (SBRT) versus surgery for operable early-stage non-small cell lung cancer (ES-NSCLC) remains highly debated. Herein, we used spatial proteomics to identify whether any molecular biomarker(s) associate with the efficacy of either modality, in efforts to optimize treatment selection between surgery and SBRT for this population.

METHODS AND MATERIALS

We evaluated biopsy tissue samples from 44 patients with ES-NSCLC treated with first-line SBRT (cohort 1) by GeoMx Digital Spatial Profiling (DSP) with a panel of 70 proteins in 5 spatial molecular compartments: tumor (panCK+), leukocyte (CD45+), lymphocyte (CD3+), macrophage (CD68+), and stroma (α-SMA+). To validate the findings in cohort 1, biopsy samples from 52 patients with ES-NSCLC who received SBRT (cohort 2) and 62 patients with ES-NSCLC who underwent surgery (cohort 3) were collected and analyzed by multiplex immunofluorescence (mIF).

RESULTS

In cohort 1, higher CD44 expression in the lymphocyte compartment was associated with poorer recurrence-free survival (RFS) (DSP: P < .001; mIF: P < .001) and higher recurrence rate (DSP: P = .001; mIF: P = .004). mIF data from cohort 2 validated these findings (P < .05 for all). From cohort 3, higher lymphocyte CD44 predicted higher RFS after surgery (P = .003). Intermodality comparisons demonstrated that SBRT was associated with significantly higher RFS over surgery in CD44-low patients (P < .001), but surgery was superior to SBRT in CD44-high cases (P = .016).

CONCLUSIONS

Lymphocyte CD44 may not only be a predictor of SBRT efficacy in this population but also an important biomarker (pending validation by large prospective data) that could better sharpen selection for SBRT versus surgery in ES-NSCLC.

Tumor Markers as Predictors of Acute Kidney Injury Incidence and Staging of the Muscle-Invasive Bladder Cancer Receiving Chemoradiation Therapy

Background

Bladder cancer, as one of types of cancers within the urinary tract, is associated with a greater risk of acute kidney injury (AKI), resulting in a poorer prognosis, discontinuation of effective oncological treatments, longer hospitalization, and higher expenses. There is no discussion yet on tumor markers in bladder cancer. With the revolutionary advances in bladder cancer molecular subtyping over the past decade, the presence of tumor markers to assess the staging of bladder cancer has yet to be discussed. In this study, we intended to assess the relationship between tumor markers and incidence of AKI, also between tumor markers and the cancer staging.

Methods

This retrospective cross-sectional study utilized secondary data from 26 medical records of patients diagnosed with bladder cancer at the Adam Malik and Universitas Sumatera Utara Hospital between 2021and 2022. This study included all patients with bladder cancer who met the inclusion criteria. Continuous variables were reported as mean (standard deviation (SD)) and examined using an independent t-test. Categorical variables were reported as proportions, examined using Chi-square or Fisher's exact test. Pre- and post-tumor marker data were evaluated with dependent sample t-test for normal variance data, and Wilcoxon test for data with atypical distribution. P values were set at 0.05.

Results

CD44 (P = 0.003) and programmed cell death 1 (PD-1) (P = 0.030) were the only significant markers in their pre- and post-chemoradiation states among the four investigated tumor markers in this study. Meanwhile, PD-1 tumor marker levels were only found to be significant between AKI and pre-chemoradiation (P = 0.011). Even though the multivariate study of tumor staging did not show any statistical significance, both tumor markers CD44 and PD-1 showed a significant effect on the incidence of acute renal damage (P = 0.034).

Conclusions

Pre-chemoradiation PD-1 tumor markers showed promise as good predictive indicators for staging and AKI incidence in muscle-invasive bladder cancer patients undergoing chemoradiation therapy.

Effects of Scaffolds on Urine- and Urothelial Carcinoma Tissue-Derived Organoids from Bladder Cancer Patients

Organoids are three-dimensional constructs generated by placing cells in scaffolds to facilitate the growth of cultures with cell-cell and cell-matrix interactions close to the in vivo situation. Organoids may contain different types of cells, including cancer cells, progenitor cells, or differentiated cells. As distinct culture conditions have significant effects on cell metabolism, we explored the expansion of cells and expression of marker genes in bladder cancer cells expanded in two different common scaffolds. The cells were seeded in basement membrane extract (BME; s.c., Matrigel®) or in a cellulose-derived hydrogel (GrowDex®, GD) and cultured. The size of organoids and expression of marker genes were studied. We discovered that BME facilitated the growth of significantly larger organoids of cancer cell line RT112 (p < 0.05), cells from a solid tumor (p < 0.001), and a voiding urine sample (p < 0.001). Expression of proliferation marker Ki76, transcription factor TP63, cytokeratin CK20, and cell surface marker CD24 clearly differed in these different tumor cells upon expansion in BME when compared to cells in GD. We conclude that the choice of scaffold utilized for the generation of organoids has an impact not only on cell growth and organoid size but also on protein expression. The disadvantages of batch-to-batch-variations of BME must be balanced with the phenotypic bias observed with GD scaffolds when standardizing organoid cultures for clinical diagnoses.

Altered Glycosylation in Progression and Management of Bladder Cancer

Bladder cancer (BC) is the 10th most common malignancy worldwide, with an estimated 573,000 new cases and 213,000 deaths in 2020. Available therapeutic approaches are still unable to reduce the incidence of BC metastasis and the high mortality rates of BC patients. Therefore, there is a need to deepen our understanding of the molecular mechanisms underlying BC progression to develop new diagnostic and therapeutic tools. One such mechanism is protein glycosylation. Numerous studies reported changes in glycan biosynthesis during neoplastic transformation, resulting in the appearance of the so-called tumor-associated carbohydrate antigens (TACAs) on the cell surface. TACAs affect a wide range of key biological processes, including tumor cell survival and proliferation, invasion and metastasis, induction of chronic inflammation, angiogenesis, immune evasion, and insensitivity to apoptosis. The purpose of this review is to summarize the current information on how altered glycosylation of bladder cancer cells promotes disease progression and to present the potential use of glycans for diagnostic and therapeutic purposes.

The molecular basis of immuno-radiotherapy

PURPOSE

Radiotherapy (RT) and immunotherapy are powerful anti-tumor treatment modalities. Experimental research has demonstrated an important interplay between the cytotoxic effects of RT and the immune system. This systematic review provides an overview of the basics of anti-tumor immunity and focuses on the mechanisms underlying the interplay between RT and immune anti-tumor response that set the molecular basis of immuno-RT.

CONCLUSIONS

An 'immunity acquired equilibrium' mimicking tumor dormancy can be achieved post-irradiation treatment, with the balance shifted toward tumor eradication or regrowth when immune cells' cytotoxic effects or cancer proliferation rate prevail, respectively. RT has both immunosuppressive and immune-enhancing properties. The latter effect is also known as radio-vaccination. Its mechanisms involve up- or down-regulation of membrane molecules, such as PD-L1, HLA-class-I, CD80/86, CD47, and Fas/CD95, that play a vital role in immune checkpoint pathways and increased cytokine expression (e.g. INFα,β,γ, IL1,2, and TNFα) by cancer or immune cells. Moreover, the interactions of radiation with the tumor microenvironment (fibroblasts, tumor-infiltrating lymphocytes, monocytes, and dendritic cells are also an important component of radio-vaccination. Thus, RT may have anti-tumor vaccine properties, whose sequels can be exploited by immunotherapy agents to treat different cancer subtypes effectively.

Radiation Treatment Timing and Dose Delivery: Effects on Bladder Cancer Cells in 3D in Vitro Culture

While radical cystectomy remains the primary treatment of choice for bladder cancer, increased evidence supports the use of bladder-preservation strategies based on adjuvant radiotherapy. This highlights the need for a better understanding of bladder cancer radiosensitivity to different types of treatment deliveries. The purpose of this study is to analyze the effect of treatment time, dose and fractionation on the number and sizes of grown three-dimensional (3D) bladder cancer spheres, and to assess the capacity of the linear-quadratic model in describing the response of cells cultured in 3D. 3D MatrigelTM-based cultures were employed to enrich for cancer stem cells (CSCs) from three human bladder cancer cell lines, RT4, T24 and UM-UC-3. Three single dose radiation treatments were performed at different time points after plating, and sphere number and sizes were assessed. Anti-CD44 immunofluorescence, clonogenic assay and anti-γH2AX staining were also performed to analyze the cell lines’ radiosensitivity. The radiosensitivity of spheres was dependent on the treatment timing after plating. Current linear quadratic dose fractionation models were shown to over-estimate radiosensitivity in 3D models. Our results showed the importance of treatment timing on the radio-response of bladder cancer spheres. We also demonstrated that bladder cancer spheres are more resistant to dose-fractionation than the estimation from the theoretical linear-quadratic model.

An Integrated Bioinformatics Analysis towards the Identification of Diagnostic, Prognostic, and Predictive Key Biomarkers for Urinary Bladder Cancer

Simple Summary

Bladder cancer is evidently a challenge as far as its prognosis and treatment are concerned. The investigation of potential biomarkers and therapeutic targets is indispensable and still in progress. Most studies attempt to identify differential signatures between distinct molecular tumor subtypes. Therefore, keeping in mind the heterogeneity of urinary bladder tumors, we attempted to identify a consensus gene-related signature between the common expression profile of bladder cancer and control samples. In the quest for substantive features, we were able to identify key hub genes, whose signatures could hold diagnostic, prognostic, or therapeutic significance, but, primarily, could contribute to a better understanding of urinary bladder cancer biology.

Abstract

Bladder cancer (BCa) is one of the most prevalent cancers worldwide and accounts for high morbidity and mortality. This study intended to elucidate potential key biomarkers related to the occurrence, development, and prognosis of BCa through an integrated bioinformatics analysis. In this context, a systematic meta-analysis, integrating 18 microarray gene expression datasets from the GEO repository into a merged meta-dataset, identified 815 robust differentially expressed genes (DEGs). The key hub genes resulted from DEG-based protein–protein interaction and weighted gene co-expression network analyses were screened for their differential expression in urine and blood plasma samples of BCa patients. Subsequently, they were tested for their prognostic value, and a three-gene signature model, including COL3A1, FOXM1, and PLK4, was built. In addition, they were tested for their predictive value regarding muscle-invasive BCa patients’ response to neoadjuvant chemotherapy. A six-gene signature model, including ANXA5, CD44, NCAM1, SPP1, CDCA8, and KIF14, was developed. In conclusion, this study identified nine key biomarker genes, namely ANXA5, CDT1, COL3A1, SPP1, VEGFA, CDCA8, HJURP, TOP2A, and COL6A1, which were differentially expressed in urine or blood of BCa patients, held a prognostic or predictive value, and were immunohistochemically validated. These biomarkers may be of significance as prognostic and therapeutic targets for BCa.

Radiation Response of Human Leukemia/Lymphoma Cells was Improved by 7-Geranyloxycoumarin

Objectives

Adult T-cell leukemia/lymphoma (ATLL) is a blood neoplasm with specific geographic distribution. Although radiotherapy is a palliative treatment that provides long-term local control, single use of radiation leads to complications for patients. To introduce a novel multimodal approach against ATLL, we investigated combinatorial effects of 7-geranyloxycoumarin and radiation in vitro.

Methods

Viability of MT-2 cells was determined by resazurin assay upon administration of 7-geranyloxycoumarin alone and followed by radiation. Then, apoptosis was detected by annexin V and propidium iodide, and the expression of candidate genes was analyzed by qPCR.

Results

Findings revealed significant (P<.0001) improvement in radiation effects upon 7-geranyloxycoumarin pretreatment, most notably when cells were pretreated with 5 µg/ml 7-geranyloxycoumarin for 96 h, exposed to 6 Gy radiation and recovered for 48 h. These results were confirmed by flow cytometry, as the percentage of early and late apoptotic cells was increased after combinatorial treatment. In addition, significant (P< .0001) changes in CD44, c-MYC, cFLIPL, BMI-1, NF-κB (Rel A), and P53 expression was induced by 7-geranyloxycoumarin and radiation.

Conclusions

Current research indicated, for the first time, that combinatorial use of 7-geranyloxycoumarin and ionizing radiation could be considered as an effective therapeutic modality for ATLL.

Near-Infrared Photoimmunotherapy (NIR-PIT) in Urologic Cancers

Near-infrared photoimmunotherapy (NIR-PIT) is a novel molecularly-targeted therapy that selectively kills cancer cells by systemically injecting an antibody-photoabsorber conjugate (APC) that binds to cancer cells, followed by the application of NIR light that drives photochemical transformations of the APC. APCs are synthesized by selecting a monoclonal antibody that binds to a receptor on a cancer cell and conjugating it to IRDye700DX silica-phthalocyanine dye. Approximately 24 h after APC administration, NIR light is delivered to the tumor, resulting in nearly-immediate necrotic cell death of cancer cells while causing no harm to normal tissues. In addition, NIR-PIT induces a strong immunologic effect, activating anti-cancer immunity that can be further boosted when combined with either immune checkpoint inhibitors or immune suppressive cell-targeted (e.g., regulatory T cells) NIR-PIT. Currently, a global phase III study of NIR-PIT in recurrent head and neck squamous cell carcinoma is ongoing. The first APC and NIR laser systems were approved for clinical use in September 2020 in Japan. In the near future, the clinical applications of NIR-PIT will expand to other cancers, including urologic cancers. In this review, we provide an overview of NIR-PIT and its possible applications in urologic cancers.

Chitosan-based nanodelivery systems for cancer therapy: Recent advances

Nowadays, cancer is one of the most prominent issues related to human health since it causes more than one-tenth of death cases throughout the world. On the other hand, routine therapeutic approaches in cancer suppression such as radiation therapy, chemotherapy, surgery, etc. due to their undesirable therapeutic outputs, including low efficiency in cancer inhibition, non-targeted drug delivery, nonselective distribution, and enormous side effects, have been indicated inefficient potency in cancer therapy or at least its growth inhibition. As a result, the development of novel and practical therapeutic methods such as nanoparticle-based drug delivery systems can be outstandingly beneficial in cancer suppression. Among various nanoparticles used in the delivery of bioactive to the tumor site, chitosan (CS) nanoparticles have received high attention. CS, poly [β-(1-4)-linked-2-amino-2-deoxy-d-glucose], is a natural linear amino polysaccharide derived from chitin which is made of irregularly distributed d-glucosamine and N-acetyl-d-glucosamine units. CS nanoparticles owing to their appropriate aspects, including nanometric size, great drug loading efficacy, ease of manipulation, non-toxicity, excellent availability and biocompatibility, good serum stability, long-term circulation time, suitable pharmacokinetic and pharmacodynamics, non-immunogenicity, and enhanced drug solubility in the human body, have been designated as an efficient candidate for drug delivery systems. They can be involved in both passive (based on the enhanced permeability and retention effect cancer targeting) and active (receptor-mediated or stimuli-responsive cancer targeting) drug delivery systems for potential cancer therapy. This review presents the properties, preparation, modification, and numerous pharmaceutical applications of CS-based drug nanodelivery systems in the diagnosis and therapy of cancer.

The clinicopathological and prognostic value of CD44 expression in bladder cancer: a study based on meta-analysis and TCGA data

CD44 is reported to be involved in tumor invasion and metastasis. However, the role of cancer stem cell marker CD44 in bladder cancer still remains controversial. Hence, the correlations between CD44 expression and the clinicopathological features and the prognosis of bladder cancer were investigated. Publications using immunohistochemical methods were identified. The Cancer Genome Atlas (TCGA) data were also analyzed. The odds ratios (ORs) or hazard ratios (HRs) with their 95% confidence intervals (95% CIs) were calculated. 14 studies involving 1107 tissue samples were included. CD44 expression in bladder cancer was lower than in non-tumor tissue samples (OR = 0.14, P = 0.005), which was consistent with TCGA data. CD44 expression was correlated with advanced T stage (OR = 1.76, P = 0.029) and lymph node metastasis (OR = 4.09, P < 0.001). Multivariate survival analysis showed that CD44 expression was not linked to tumor-specific survival, overall survival, and recurrence/relapse-free survival, but was associated with disease failure (HR = 2.912, 95% CI = 1.51-5.61). No relationships of CD44 expression with the clinicopathological features and overall survival were found from TCGA data. Our finding suggested that CD44 expression may be correlated with progression, metastasis, and disease failure of bladder cancer. However, further large-scale studies are needed.Abbreviations: CD44: Cluster of Differentiation 44; CIs: Confidence Intervals; CSCs: Cancer Stem Cells; EMT: Epithelial-mesenchymal Transition; HRs: Hazard Ratios; ORs: Odds Ratios; TCGA: The Cancer Genome Atlas.

Treating Bladder Cancer: Engineering of Current and Next Generation Antibody-, Fusion Protein-, mRNA-, Cell- and Viral-Based Therapeutics

Bladder cancer is a frequent malignancy and has a clinical need for new therapeutic approaches. Antibody and protein technologies came a long way in recent years and new engineering approaches were applied to generate innovative therapeutic entities with novel mechanisms of action. Furthermore, mRNA-based pharmaceuticals recently reached the market and CAR-T cells and viral-based gene therapy remain a major focus of biomedical research. This review focuses on the engineering of biologics, particularly therapeutic antibodies and their application in preclinical development and clinical trials, as well as approved monoclonal antibodies for the treatment of bladder cancer. Besides, newly emerging entities in the realm of bladder cancer like mRNA, gene therapy or cell-based therapeutics are discussed and evaluated. As many discussed molecules exhibit unique mechanisms of action based on innovative protein engineering, they reflect the next generation of cancer drugs. This review will shed light on the engineering strategies applied to develop these next generation treatments and provides deeper insights into their preclinical profiles, clinical stages, and ongoing trials. Furthermore, the distribution and expression of the targeted antigens and the intended mechanisms of action are elucidated.

Linking Serine/Glycine Metabolism to Radiotherapy Resistance

Simple Summary

Hyperactivation of the de novo serine/glycine biosynthesis across different cancer types and its critical contribution in tumor initiation, progression, and therapy resistance indicate the relevance of serine/glycine metabolism-targeted therapies as therapeutic intervention in cancer. In this review, we specifically focus on the contribution of the de novo serine/glycine biosynthesis pathway to radioresistance. We provide a future perspective on how de novo serine/glycine biosynthesis inhibition and serine-free diets may improve the outcome of radiotherapy. Future research in this field is needed to better understand serine/glycine metabolic reprogramming of cancer cells in response to radiation and the influence of this pathway in the tumor microenvironment, which may provide the rationale for the optimal combination therapies.

Abstract

The activation of de novo serine/glycine biosynthesis in a subset of tumors has been described as a major contributor to tumor pathogenesis, poor outcome, and treatment resistance. Amplifications and mutations of de novo serine/glycine biosynthesis enzymes can trigger pathway activation; however, a large group of cancers displays serine/glycine pathway overexpression induced by oncogenic drivers and unknown regulatory mechanisms. A better understanding of the regulatory network of de novo serine/glycine biosynthesis activation in cancer might be essential to unveil opportunities to target tumor heterogeneity and therapy resistance. In the current review, we describe how the activation of de novo serine/glycine biosynthesis in cancer is linked to treatment resistance and its implications in the clinic. To our knowledge, only a few studies have identified this pathway as metabolic reprogramming of cancer cells in response to radiation therapy. We propose an important contribution of de novo serine/glycine biosynthesis pathway activation to radioresistance by being involved in cancer cell viability and proliferation, maintenance of cancer stem cells (CSCs), and redox homeostasis under hypoxia and nutrient-deprived conditions. Current approaches for inhibition of the de novo serine/glycine biosynthesis pathway provide new opportunities for therapeutic intervention, which in combination with radiotherapy might be a promising strategy for tumor control and ultimately eradication. Further research is needed to gain molecular and mechanistic insight into the activation of this pathway in response to radiation therapy and to design sophisticated stratification methods to select patients that might benefit from serine/glycine metabolism-targeted therapies in combination with radiotherapy.

MicroRNAs: Their Role in Metastasis, Angiogenesis, and the Potential for Biomarker Utility in Bladder Carcinomas

Angiogenesis is the process of generating new capillaries from pre-existing blood vessels with a vital role in tumor growth and metastasis. MicroRNAs (miRNAs) are noncoding RNAs that exert post-transcriptional control of protein regulation. They participate in the development and progression of several cancers including bladder cancer (BLCA). In cancer tissue, changes in microRNA expression exhibit tissue specificity with high levels of stability and detectability. miRNAs are less vulnerable to degradation, making them novel targets for therapeutic approaches. A suitable means of targeting aberrant activated signal transduction pathways in carcinogenesis of BLCA is possibly through altering the expression of key miRNAs that regulate them, exerting a strong effect on signal transduction. Precaution must be taken, as the complexity of miRNA regulation might result in targeting several downstream tumor suppressors or oncogenes, enhancing the effect further. Since exosomes contain both mRNA and miRNA, they could therefore possibly be more effective in targeting a recipient cell if they deliver a specific miRNA to modify the recipient cell protein production and gene expression. In this review, we discuss the molecules that have been shown to play a significant role in BLCA tumor development. We also discuss the roles of various miRNAs in BLCA angiogenesis and metastasis. Advances in the management of metastatic BLCA have been limited; miRNA mimics and molecules targeted at miRNAs (anti-miRs) as well as exosomes could serve as therapeutic modalities or as diagnostic biomarkers.

Targeted Delivery of Therapeutics to Urological Cancer Stem Cells

Urological cancer refers to cancer in organs of the urinary system and the male reproductive system. It mainly includes prostate cancer, bladder cancer, renal cancer, etc., seriously threatening patients' survival. Although there are many advances in the treatment of urological cancer, approved targeted therapies often result in tumor recurrence and therapy failure. An increasing amount of evidence indicated that cancer stem cells (CSCs) with tumor-initiating ability were the source of treatment failure in urological cancer. The development of CSCstargeted strategy can provide a possibility for the complete elimination of urological cancer. This review is based on a search of PubMed, Google scholar and NIH database (http://ClinicalTrials.gov/) for English language articles containing the terms: "biomarkers", "cancer stem cells", "targeting/targeted therapy", "prostate cancer", bladder cancer" and "kidney cancer". We summarized the biomarkers and stem cell features of the prostate, bladder and renal CSCs, outlined the targeted strategies for urological CSCs from signaling pathways, cytokines, angiogenesis, surface markers, elimination therapy, differentiation therapy, immunotherapy, microRNA, nanomedicine, etc., and highlighted the prospects and future challenges in this research field.

Self-crosslinkable chitosan-hyaluronic acid dialdehyde nanoparticles for CD44-targeted siRNA delivery to treat bladder cancer

Bladder cancer is one of the concerning malignancies worldwide, which is lacking effective targeted therapy. Gene therapy is a potential approach for bladder cancer treatment. While, a safe and effective targeted gene delivery system is urgently needed for prompting the bladder cancer treatment in vivo. In this study, we confirmed that the bladder cancer had CD44 overexpression and small interfering RNAs (siRNA) with high interfere to Bcl2 oncogene were designed and screened. Then hyaluronic acid dialdehyde (HAD) was prepared in an ethanol-water mixture and covalently conjugated to the chitosan nanoparticles (CS-HAD NPs) to achieve CD44 targeted siRNA delivery. The in vitro and in vivo evaluations indicated that the siRNA-loaded CS-HAD NPs (siRNA@CS-HAD NPs) were approximately 100 nm in size, with improved stability, high siRNA encapsulation efficiency and low cytotoxicity. CS-HAD NPs could target to CD44 receptor and deliver the therapeutic siRNA into T24 bladder cancer cells through a ligand-receptor-mediated targeting mechanism and had a specific accumulation capacity in vivo to interfere the targeted oncogene Bcl2 in bladder cancer. Overall, a CD44 targeted gene delivery system based on natural macromolecules was developed for effective bladder cancer treatment, which could be more conducive to clinical application due to its simple preparation and high biological safety.

CSC Radioresistance: A Therapeutic Challenge to Improve Radiotherapy Effectiveness in Cancer

Radiotherapy (RT) is a modality of oncologic treatment that can be used to treat approximately 50% of all cancer patients either alone or in combination with other treatment modalities such as surgery, chemotherapy, immunotherapy, and therapeutic targeting. Despite the technological advances in RT, which allow a more precise delivery of radiation while progressively minimizing the impact on normal tissues, issues like radioresistance and tumor recurrence remain important challenges. Tumor heterogeneity is responsible for the variation in the radiation response of the different tumor subpopulations. A main factor related to radioresistance is the presence of cancer stem cells (CSC) inside tumors, which are responsible for metastases, relapses, RT failure, and a poor prognosis in cancer patients. The plasticity of CSCs, a process highly dependent on the epithelial–mesenchymal transition (EMT) and associated to cell dedifferentiation, complicates the identification and eradication of CSCs and it might be involved in disease relapse and progression after irradiation. The tumor microenvironment and the interactions of CSCs with their niches also play an important role in the response to RT. This review provides a deep insight into the characteristics and radioresistance mechanisms of CSCs and into the role of CSCs and tumor microenvironment in both the primary tumor and metastasis in response to radiation, and the radiobiological principles related to the CSC response to RT. Finally, we summarize the major advances and clinical trials on the development of CSC-based therapies combined with RT to overcome radioresistance. A better understanding of the potential therapeutic targets for CSC radiosensitization will provide safer and more efficient combination strategies, which in turn will improve the live expectancy and curability of cancer patients.

Knockdown of Musashi RNA Binding Proteins Decreases Radioresistance but Enhances Cell Motility and Invasion in Triple-Negative Breast Cancer

The therapeutic potential of Musashi (MSI) RNA-binding proteins, important stemness-associated gene expression regulators, remains insufficiently understood in breast cancer. This study identifies the interplay between MSI protein expression, stem cell characteristics, radioresistance, cell invasiveness and migration. MSI-1, MSI-2 and Notch pathway elements were investigated via quantitative polymerase chain reaction (qPCR) in 19 triple-negative breast cancer samples. Measurements were repeated in MDA-MB-231 cells after MSI-1 and -2 siRNA-mediated double knockdown, with further experiments performed after MSI silencing. Flow cytometry helped quantify expression of CD44 and leukemia inhibitory factor receptor (LIFR), changes in apoptosis and cell cycle progression. Proliferation and irradiation-induced effects were assessed using colony formation assays. Radiation-related proteins were investigated via Western blots. Finally, cell invasion assays and digital holographic microscopy for cell migration were performed. MSI proteins showed strong correlations with Notch pathway elements. MSI knockdown resulted in reduction of stem cell marker expression, cell cycle progression and proliferation, while increasing apoptosis. Cells were radiosensitized as radioresistance-conferring proteins were downregulated. However, MSI-silencing-mediated LIFR downregulation resulted in enhanced cell invasion and migration. We conclude that, while MSI knockdown results in several therapeutically desirable consequences, enhanced invasion and migration need to be counteracted before knockdown advantages can be fully exploited.

The Role of Cancer Stem Cells in Radiation Resistance

Cancer stem cells (CSC) are a distinct subpopulation within a tumor. They are able to self-renew and differentiate and possess a high capability to repair DNA damage, exhibit low levels of reactive oxygen species (ROS), and proliferate slowly. These features render CSC resistant to various therapies, including radiation therapy (RT). Eradication of all CSC is a requirement for an effective antineoplastic treatment and is therefore of utmost importance for the patient. This makes CSC the prime targets for any therapeutic approach. Albeit clinical data is still scarce, experimental data and first clinical trials give hope that CSC-targeted treatment has the potential to improve antineoplastic therapies, especially for tumors that are known to be treatment resistant, such as glioblastoma. In this review, we will discuss CSC in the context of RT, describe known mechanisms of resistance, examine the possibilities of CSC as biomarkers, and discuss possible new treatment approaches.

Synergic effects of cancer stem cells markers, CD44 and embryonic stem cell transcription factor Nanog, on bladder cancer prognosis

Background: Therapy that targets cancer stem cells has the potential to eradicate cancer and prevent tumour recurrence. Therefore, we hypothesized the combined prognostic significance of stem cell markers CD44 (prevalent in basal layer of urothelial carcinoma) and Nanog (embryonic stem cell transcription factor) in bladder cancer.Material and Methods: CD44 and Nanog expression were determined by immunohistochemistry in 112 bladder cancer cases of which 79 were non-muscle invasive and 33 muscle invasive.Results: A significant correlation was found between CD44 and Nanog expression (r = 0.41, p < 0.001). The bladder cancer patients with high CD44 and Nanog expression had poor recurrence-free survival and poor overall survival (all p < 0.01). Multivariate Cox regression analysis identified lymph node positivity (hazard ratio; HR 3.81, 95% confidence interval; CI 1.66-8.75), CD44 (HR/95%CI 7.03 [3.04-16.22]) and Nanog (HR/95%CI 2.89 [1.23-6.77]) as independent prognostic biomarkers for recurrence-free survival, whilst a combined index of CD44 and Nanog expression (high expression group; HR/95%CI 25.45 [6.71-96.50] for recurrence-free survival) and lymph node positivity (HR/95%CI 3.68 [1.63-8.33] for recurrence-free survival) were independent prognostic biomarkers for recurrence-free survival and overall survival (all p < 0.001).Conclusions: A combined index of CD44 and Nanog expression is a promising prognostic predictor of recurrence-free survival and overall survival in bladder cancer. It may help identification of patients who will benefit from intensive treatment.

Importance of PNO1 for growth and survival of urinary bladder carcinoma: Role in core-regulatory circuitry

PNO1 (partner of Nob1) was known as a RNA‐binding protein in humans, and its ortholog PNO1 was reported to participate ribosome and proteasome biogenesis in yeasts. Yet there have been few studies about its functions in mammalian cells, and so far its role in human cells has never been reported, especially in urinary bladder cancer (UBC).We interrogated the cellular functions and clinical significance of PNO1 in, and its molecular mechanism through microarrays and bioinformatics analysis. Our findings support that PNO1 participates in promoting proliferation and colonogenesis, while reducing apoptosis of UBC cells, and is also predicted to be associated with the migration and metastasis of UBC PNO1 knockdown (KD) attenuated the tumorigenesis ability of UBC in mouse. PNO1 KD led to the altered expression of 1543 genes that are involved in a number of signalling pathways, biological functions and regulation networks. CD44, PTGS2, cyclin D1, CDK1, IL‐8, FRA1, as well as mTOR, p70 S6 kinase, p38 and Caspase‐3 proteins were all down‐regulated in PNO1 KD cells, suggesting the involvement of PNO1 in inflammatory responses, cell cycle regulation, chemotaxis, cell growth and proliferation, apoptosis, cell migration and invasiveness. This study will enhance our understanding of the molecular mechanism of UBC and may eventually provide novel targets for individualized cancer therapy.

c-Myc Acts as a Competing Endogenous RNA to Sponge miR-34a, in the Upregulation of CD44, in Urothelial Carcinoma

MicroRNAs (miRNAs) have been shown to play a crucial role in the progression of human cancers, including urothelial carcinoma (UC), the sixth-most common cancer in the world. Among them, miR-34a has been implicated in the regulation of cancer stem cells (CSCs); however, its role in UC has yet to be fully elucidated. In this study, bioinformatics and experimental analysis confirmed that miR-34a targets CD44 (a CSC surface marker) and c-Myc (a well-known cell cycle regulator) in UC. We found that, surprisingly, most UC cell lines and patient samples did express miR-34a, although epigenetic silencing by promoter hypermethylation of miR-34a expression was observed only in UMUC3 cells, and a subset of patient samples. Importantly, overexpression of c-Myc, a frequently amplified oncogene in UC, was shown to upregulate CD44 expression through a competing endogenous RNA (ceRNA) mechanism, such that overexpression of the c-Myc 3'UTR upregulated CD44, and vice versa. Importantly, we observed a positive correlation between the expression of c-Myc and CD44 in clinical samples obtained from UC patients. Moreover, overexpression of a dominant-negative p53 mutant downregulated miR-34a, but upregulated c-Myc and CD44, in UC cell lines. Functionally, the ectopic expression of miR-34a was shown to significantly suppress CD44 expression, and subsequently, suppression of cell growth and invasion capability, while also reducing chemoresistance. In conclusion, it appears that aberrant promoter methylation, and c-Myc-mediated ceRNA mechanisms, may attenuate the function of miR-34a, in UC. The tumor suppressive role of miR-34a in controlling CSC phenotypes in UC deserves further investigation.

'Stemness' and 'senescence' related escape pathways are dose dependent in lung cancer cells surviving post irradiation

AIMS

Lung cancer is one of the main causes of cancer-related deaths worldwide and radiotherapy is a major treatment of choice. However, radioresistance is a main reason for radiotherapy failure or tumor relapse. Here, we investigated possible mechanisms associated with cancer cell radioresistance.

MATERIALS AND METHODS

We compared two newly derived cell lines, namely A549-IR3 and A549-IR6, which survived repeated (3 or 6 times) 4 Gy exposure of parental A549 lung cancer cell line. DNA repair ability, stemness and senescence were comparatively studied.

KEY FINDINGS

A549-IR3 exhibited higher proliferation ability and radioresistance compared to parental and A549-IR6 cells. Enhanced radioresistance was not accompanied by chemoresistance to cisplatin or docetaxel. DNA repair kinetics (γΗ2ΑΧ expression) were similar in all cell lines. A549-IR3 cells exhibited a significant rise in stem cell markers (CD44, CD133, OCT4, SOX2 and NANOG) whereas A549-IR6 displayed an increased senescent population.

SIGNIFICANCE

Cancer cells surviving after radiotherapy may follow two different escape pathways: selection for radioresistance resulting in regrowth, and in clinical terms relapse, or above an irradiation threshold, stem-cells die and cancer cells become senescent, leading the tumor to a state of dormancy.

Keratin 17 is a sensitive and specific biomarker of urothelial neoplasia

There is a clinical need to identify novel biomarkers to improve diagnostic accuracy for the detection of urothelial tumors. The current study aimed to evaluate keratin 17 (K17), an oncoprotein that drives cell cycle progression in cancers of multiple anatomic sites, as a diagnostic biomarker of urothelial neoplasia in bladder biopsies and in urine cytology specimens. We evaluated K17 expression by immunohistochemistry in formalin-fixed, paraffin embedded tissue specimens of non-papillary invasive urothelial carcinoma (UC) (classical histological cases), high grade papillary UC (PUC-LG), low grade papillary UC (PUC-HG), papillary urothelial neoplasia of low malignant potential (PUNLMP), and normal bladder mucosa. A threshold was established to dichotomize K17 status in tissue specimens as positive vs. negative, based on the proportion of cells that showed strong staining. In addition, K17 immunocytochemistry was performed on urine cytology slides, scoring positive test results based on the detection of K17 in any urothelial cells. Mann-Whitney and receiver operating characteristic analyses were used to compare K17 expression between histologic diagnostic categories. The median proportion of K17 positive tumor cells was 70% (range 20-90%) in PUNLMP, 30% (range 5-100%) in PUC-LG, 20% (range 1-100%), in PUC-HG, 35% (range 5-100%) in UC but staining was rarely detected (range 0-10%) in normal urothelial mucosa. Defining cases in which K17 was detected in ≥10% of cells were considered positive, the sensitivity of K17 in biopsies was 89% (95% CI: 80-96%) and the specificity was 88% (95% CI: 70-95%) to distinguish malignant lesions (PUC-LG, PUC-HG, and UC) from normal urothelial mucosa. Furthermore, K17 immunocytochemistry had a sensitivity of 100% and a specificity of 96% for urothelial carcinoma in 112 selected urine specimens. Thus, K17 is a sensitive and specific biomarker of urothelial neoplasia in tissue specimens and should be further explored as a novel biomarker for the cytologic diagnosis of urine specimens.

Cancer stem cells in radiation response: current views and future perspectives in radiation oncology

Purpose: Despite technological improvement and advances in biology-driven patient stratification, many patients still fail radiotherapy resulting in loco-regional and distant recurrence. Tumor heterogeneity remains a key challenge to effective cancer treatment, and reliable stratification of cancer patients for prediction of outcomes is highly important. Intratumoral heterogeneity is manifested at the different levels, including different tumorigenic properties of cancer cells. Since John Dick et al. isolated leukemia initiating cells in 1990, the populations of tumor initiating or cancer stem cells (CSCs) were identified and characterized also for a broad spectrum of solid tumor types. The properties of CSCs are of considerable clinical relevance: CSCs have self-renewal and tumor initiating potential, and the metastases are initiated by the CSC clones with the ability to disseminate from the primary tumor site. Conclusion: Evidence from both, experimental and clinical studies demonstrates that the probability of achieving local tumor control by radiation therapy depends on the complete eradication of CSC populations. The number, properties and molecular signature of CSCs are highly predictive for clinical outcome of radiotherapy, whereas targeted therapies against CSCs combined with conventional treatment are expected to provide an improved clinical response and prevent tumor relapse. In this review, we discuss the modern methods to study CSCs in radiation biology, the role of CSCs in personalized cancer therapy as well as future directions for CSC research in translational radiooncology.

Molecular characterization of low grade and high grade bladder cancer

Background

Bladder cancer (BC) is the 9^th most common cancer diagnosis worldwide. Low grade (LG) represents 70% of all BCs, characterized by recurrence and rare ability (10–15%) to progress to high grade (HG) and invade. The remaining 30% is high grade (HG), fast invasive BC, which is resistant to therapy. Identifying biomarkers for predicting those tumors able to progress is a key goal for patient outcome improvement. This study focuses on the most promising prognostic markers.

Materials and methods

TP53 and FGFR3 mutational status, Survivin, CK19, CK20, E-cadherin and CD44 gene expression analysis were performed on 66 BCs.

Results

Survivin was found associated to tumor grade (p<0.05). Moreover, Survivin correlated with CD44 in TP53 wild type (p = 0.0242) and FGFR3 wild type (p = 0.0036) tumors. In particular the Survivin-CD44 correlation was associated to HG FGFR3 wild type BCs (p = 0.0045). Unsupervised hierarchical clustering based on gene expression data identified four distinct molecular groups reflecting the patient histology (p = 0.038).

Conclusion

We suggest Survivin, both as a biomarker associated to G3 BCs but negatively related to TP53 mutational status, and as a potential novel therapeutic target.

A five-gene signature may predict sunitinib sensitivity and serve as prognostic biomarkers for renal cell carcinoma

Sunitinib resistance is, nowadays, the major challenge for advanced renal cell carcinoma patients. Illuminating the potential mechanisms and exploring effective strategies to overcome sunitinib resistance are highly desired. We constructed a reliable gene signature which may function as biomarkers for prediction of sunitinib sensitivity and clinical prognosis. The gene expression profiles were obtained from The Cancer Genome Atlas database. By performing GEO2R analysis, numerous differentially expressed genes (DEGs) were found to be associated with sunitinib resistance. To acquire more precise DEGs, we integrated three different microarray datasets. Functional analysis revealed that these DEGs were mainly involved in Rap1 signaling pathway, p53 signaling pathway and Ras signaling pathway. Then, top five hub genes, BIRC5, CD44, MUC1, TF, CCL5, were identified from protein-protein interaction (PPI) network. Sub-network analysis carried out by MCODE plugin revealed that key DEGs were related with PI3K-Akt signaling pathway, Rap1 signaling pathway and VEGF signaling pathway. Next, we established sunitinib-resistant OS-RC-2 and 786-O cell lines and validated the expression of five hub genes in cell lines. To further evaluate the potentials of five-gene signature for predicting clinical prognosis, we analyzed RCC patients with gene expressions and overall survival information from two independent patient datasets. The Kaplan-Meier estimated the OS of RCC patients in the low- and high-risk groups according to gene expression signature. Multivariate Cox regression analysis indicated that the prognostic power of five-gene signature was independent of clinical features. In conclusion, we developed a five-gene signature which can predict sunitinib sensitivity and OS for advanced RCC patients, providing novel insights into understanding of sunitinib-resistant mechanisms and identification of RCC patients with poor prognosis.

Predictive Value of CD44 in Muscle-Invasive Bladder Cancer and Its Relationship with IL-6 Signaling

BACKGROUND

CD44, a cancer stem cell surface marker, is associated with treatment resistance and prognosis in some cancers. In the present study, we examined the predictive value of CD44 in muscle-invasive bladder cancer (MIBC).

METHODS

We retrospectively analyzed the clinical outcomes of 105 MIBC patients and correlated these outcomes with the expression of CD44. Furthermore, the bladder cancer cell lines HT1197 and MB49 were selected for cellular and animal experiments to investigate the correlation between CD44 and tumor aggressiveness.

RESULTS

Analysis of clinical specimens indicated that CD44 staining was significantly associated with a higher clinical stage, higher locoregional failure rate, and lower disease-specific survival rate for MIBC patients. Using cellular experiments and orthotopic tumor models, we showed that CD44+ bladder cancer cells had a higher invasion ability and augmented epithelial-mesenchymal transition (EMT) compared with CD44 cells. There was a significant correlation between interleukin (IL)-6 and CD44 levels noted by in vitro testing, and clinical samples. Blockade of IL-6 attenuated the expression of CD44, cancer stem-cell-like properties, and aggressive tumor behavior in vitro and in vivo. The related changes included the attenuated STAT3 activation and EMT, and decreased programmed death ligand 1-mediated T-cell suppression.

CONCLUSION

Our findings suggest that CD44 expression is positively associated with tumor aggressiveness in bladder cancer, and activated IL-6 signaling provides a suitable microenvironment for the induction of CD44 expression.

Personalized disease signatures through information-theoretic compaction of big cancer data

Every individual cancer develops and grows in its own specific way, giving rise to a recognized need for the development of personalized cancer diagnostics. This suggested that the identification of patient-specific oncogene markers would be an effective diagnostics approach. However, tumors that are classified as similar according to the expression levels of certain oncogenes can eventually demonstrate divergent responses to treatment. This implies that the information gained from the identification of tumor-specific biomarkers is still not sufficient. We present a method to quantitatively transform heterogeneous big cancer data to patient-specific transcription networks. These networks characterize the unbalanced molecular processes that deviate the tissue from the normal state. We study a number of datasets spanning five different cancer types, aiming to capture the extensive interpatient heterogeneity that exists within a specific cancer type as well as between cancers of different origins. We show that a relatively small number of altered molecular processes suffices to accurately characterize over 500 tumors, showing extreme compaction of the data. Every patient is characterized by a small specific subset of unbalanced processes. We validate the result by verifying that the processes identified characterize other cancer patients as well. We show that different patients may display similar oncogene expression levels, albeit carrying biologically distinct tumors that harbor different sets of unbalanced molecular processes. Thus, tumors may be inaccurately classified and addressed as similar. These findings highlight the need to expand the notion of tumor-specific oncogenic biomarkers to patient-specific, comprehensive transcriptional networks for improved patient-tailored diagnostics.

Role of metabolism in cancer cell radioresistance and radiosensitization methods

BACKGROUND

Radioresistance is a major factor leading to the failure of radiotherapy and poor prognosis in tumor patients. Following the application of radiotherapy, the activity of various metabolic pathways considerably changes, which may result in the development of resistance to radiation.

MAIN BODY

Here, we discussed the relationships between radioresistance and mitochondrial and glucose metabolic pathways, aiming to elucidate the interplay between the tumor cell metabolism and radiotherapy resistance. In this review, we additionally summarized the potential therapeutic targets in the metabolic pathways.

SHORT CONCLUSION

The aim of this review was to provide a theoretical basis and relevant references, which may lead to the improvement of the sensitivity of radiotherapy and prolong the survival of cancer patients.

Variant isoforms of CD44 involves acquisition of chemoresistance to cisplatin and has potential as a novel indicator for identifying a cisplatin-resistant population in urothelial cancer

BACKGROUND

Cisplatin is the most commonly used chemotherapeutic agent in the treatment of patients with metastatic and/or recurrent urothelial cancer. However, the effectiveness of these treatments is severely limited due to the development of cisplatin resistance. Cancer stem cells have been documented as one of the key hypotheses involved in chemoresistance. CD44v8-10 has been identified as one of the new cancer stem cells markers and was recently shown to enhance the antioxidant system by interaction with xCT, a subunit of the cystine transporter modulating intracellular glutathione synthesis. The aim of the present study was to investigate the clinical role of CD44v8-10 and the molecular mechanism underlying the acquisition of cisplatin resistance through CD44v8-10 in urothelial cancer.

METHODS

We analyzed the clinical significance of the immunohistochemical CD44v9 expression, which detects the immunogen of human CD44v8-10, in 77 urothelial cancer patients treated with cisplatin-based systemic chemotherapy for recurrence and/or metastasis. We then evaluated the biological role of CD44v8-10 in the acquisition of cisplatin resistance using the urothelial cancer cell lines, T24 and T24PR, which were generated to acquire resistance to cisplatin.

RESULTS

The 5-year cancer-specific survival rate was significantly lower in the CD44v9-positive group than in the CD44v9-negative group (P = 0.008). Multivariate analyses revealed that CD44v9 positivity was an independent risk factor of cancer-specific survival (P = 0.024, hazard ratio = 5.16) in urothelial cancer patients who had recurrence and/or metastasis and received cisplatin-based chemotherapy. The expression of CD44v8-10 and xCT was stronger in T24PR cells than in T24 cells. The amount of intracellular glutathione was significantly higher in T24PR cells than in T24 cells (p < 0.001), and intracellular reactive oxygen species production by cisplatin was lower in T24PR cells than in T24 cells. Furthermore, the knockdown of CD44v8-10 by siRNA led to the recovery of cisplatin sensitivity in T24PR cells.

CONCLUSIONS

CD44v9 in tumor specimens has potential as a novel indicator for identifying a cisplatin-chemoresistant population among urothelial cancer patients. CD44v8-10 contributes to reactive oxygen species defenses, which are involved in chemoresistance, by promoting the function of xCT, which adjusts the synthesis of glutathione.