An Oncofetal Glycosaminoglycan Modification Provides Therapeutic Access to Cisplatin-resistant Bladder Cancer

Tumor-agnostic cancer therapy using antibodies targeting oncofetal chondroitin sulfate

Molecular similarities between embryonic and malignant cells can be exploited to target tumors through specific signatures absent in healthy adult tissues. One such embryonic signature tumors express is oncofetal chondroitin sulfate (ofCS), which supports disease progression and dissemination in cancer. Here, we report the identification and characterization of phage display-derived antibody fragments recognizing two distinct ofCS epitopes. These antibody fragments show binding affinity to ofCS in the low nanomolar range across a broad selection of solid tumor types in vitro and in vivo with minimal binding to normal, inflamed, or benign tumor tissues. Anti-ofCS antibody drug conjugates and bispecific immune cell engagers based on these targeting moieties disrupt tumor progression in animal models of human and murine cancers. Thus, anti-ofCS antibody fragments hold promise for the development of broadly effective therapeutic and diagnostic applications targeting human malignancies.

Plasma ofCS-modified CD44 predicts the survival of patients with lung cancer

Plasma levels of oncofetal chondroitin sulfate (ofCS)-modified CD44 have emerged as a promising biomarker for multi-cancer detection. Here, we explored its potential to predict the survival of patients with lung cancer. A prospective observational cohort was conducted involving 274 newly diagnosed patients with lung cancer at the Sun Yat-sen University Cancer Center from 2013 to 2015. The plasma levels of ofCS-modified CD44 were measured, and Cox regression analysis was performed to assess the association between plasma-modified CD44 levels and overall survival (OS) as well as other prognostic outcomes. Prognostic nomograms were constructed based on plasma ofCS-modified CD44 levels to predict survival outcomes for patients with lung cancer. Patients with high expression ofCS-modified CD44 exhibited significantly worse outcomes in terms of OS (HR = 1.61, 95%CI = 1.13-2.29, p = 0.009) and progression-free survival (PFS). These findings were consistent across various analyses. The concordance index of the prognostic nomogram for predicting OS in both the training set and validation set were 0.723 and 0.737, respectively. Additionally, time-dependent receiver operating characteristic (ROC) curves showed that the nomogram could serve as a useful tool for predicting OS in patients with lung cancer. Plasma ofCS-modified CD44 may serve as an independent prognosis marker for patients with lung cancer. Further validation of its predictive value could enhance prognostic assessment and guide personalized treatment strategies for patients with lung cancer.

Modification of lysine-260 2-hydroxyisobutyrylation destabilizes ALDH1A1 expression to regulate bladder cancer progression

ALDH1A1 is one of the classical stem cell markers for bladder cancer. Lysine 2-hydroxyisobutyrylation (Khib) is a newfound modification to modulate the protein expression, and the underlying mechanisms of how ALDH1A1 was regulated by Khib modification in bladder cancer remains unknown. Here, ALDH1A1 showed a decreased K260hib modification, as identified by protein modification omics in bladder cancer. Decreasing ALDH1A1 expression significantly suppressed the proliferation, migration and invasion of bladder cancer cells. Moreover, K260hib modification is responsible for the activity of ALDH1A1 in bladder cancer, which is regulated by HDAC2/3. Higher K260hib modification on ALDH1A1 promotes protein degradation through chaperone-mediated autophagy (CMA), and ALDH1A1 K260hib could sensitize bladder cancer cells to chemotherapeutic drugs. Higher ALDH1A1 expression with a lower K260hib modification indicates a poor prognosis in patients with bladder cancer. Overall, we demonstrated that K260hib of ALDH1A1 can be used as a potential therapeutic target for bladder cancer treatment.

Raman Spectroscopy Combined with Malaria Protein for Early Capture and Recognition of Broad-Spectrum Circulating Tumor Cells

Early identification of tumors can significantly reduce the mortality rate. Circulating tumor cells (CTCs) are a type of tumor cell that detaches from the primary tumor and circulates through the bloodstream. Monitoring CTCs may allow the early identification of tumor progression. However, due to their rarity and heterogeneity, the enrichment and identification of CTCs is still challenging. Studies have shown that Raman spectroscopy could distinguish CTCs from metastatic cancer patients. VAR2CSA, a class of malaria proteins, has a strong broad-spectrum binding effect on various tumor cells and is a promising candidate biomarker for cancer detection. Here, recombinant malaria VAR2CSA proteins were synthesized, expressed, and purified. After confirming that various types of tumor cells can be isolated from blood by recombinant malaria VAR2CSA proteins, we further proved that the VAR2CSA combined with Raman spectroscopy could be used efficiently for tumor capture and type recognition using A549 cell lines spiked into the blood. This would allow the early screening and detection of a broad spectrum of CTCs. Finally, we synthesized and purified the malaria protein fusion antibody and confirmed its in vitro tumor-killing activity. Herein, this paper exploits the theoretical basis of a novel strategy to capture, recognize, and kill broad-spectrum types of CTCs from the peripheral blood.

Bispecific T cell-engager targeting oncofetal chondroitin sulfate induces complete tumor regression and protective immune memory in mice

BACKGROUND

The malaria protein VAR2CSA binds oncofetal chondroitin sulfate (ofCS), a unique chondroitin sulfate, expressed on almost all mammalian cancer cells. Previously, we produced a bispecific construct targeting ofCS and human T cells based on VAR2CSA and anti-CD3 (V-aCD3^Hu). V-aCD3^Hu showed efficacy against xenografted tumors in immunocompromised mice injected with human immune cells at the tumor site. However, the complex effects potentially exerted by the immune system as a result of the treatment cannot occur in mice without an immune system. Here we investigate the efficacy of V-aCD3^Mu as a monotherapy and combined with immune checkpoint inhibitors in mice with a fully functional immune system.

METHODS

We produced a bispecific construct consisting of a recombinant version of VAR2CSA coupled to an anti-murine CD3 single-chain variable fragment. Flow cytometry and ELISA were used to check cell binding capabilities and the therapeutic effect was evaluated in vitro in a killing assay. The in vivo efficacy of V-aCD3^Mu was then investigated in mice with a functional immune system and established or primary syngeneic tumors in the immunologically "cold" 4T1 mammary carcinoma, B16-F10 malignant melanoma, the pancreatic KPC mouse model, and in the immunologically "hot" CT26 colon carcinoma model.

RESULTS

V-aCD3^Mu had efficacy as a monotherapy, and the combined treatment of V-aCD3^Mu and an immune checkpoint inhibitor showed enhanced effects resulting in the complete elimination of solid tumors in the 4T1, B16-F10, and CT26 models. This anti-tumor effect was abscopal and accompanied by a systemic increase in memory and activated cytotoxic and helper T cells. The combined treatment also led to a higher percentage of memory T cells in the tumor without an increase in regulatory T cells. In addition, we observed partial protection against re-challenge in a melanoma model and full protection in a breast cancer model.

CONCLUSIONS

Our findings suggest that V-aCD3^Mu combined with an immune checkpoint inhibitor renders immunologically "cold" tumors "hot" and results in tumor elimination. Taken together, these data provide proof of concept for the further clinical development of V-aCD3 as a broad cancer therapy in combination with an immune checkpoint inhibitor.

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.

Reformation of the chondroitin sulfate glycocalyx enables progression of AR-independent prostate cancer

Lineage plasticity of prostate cancer is associated with resistance to androgen receptor (AR) pathway inhibition (ARPI) and supported by a reactive tumor microenvironment. Here we show that changes in chondroitin sulfate (CS), a major glycosaminoglycan component of the tumor cell glycocalyx and extracellular matrix, is AR-regulated and promotes the adaptive progression of castration-resistant prostate cancer (CRPC) after ARPI. AR directly represses transcription of the 4-O-sulfotransferase gene CHST11 under basal androgen conditions, maintaining steady-state CS in prostate adenocarcinomas. When AR signaling is inhibited by ARPI or lost during progression to non-AR-driven CRPC as a consequence of lineage plasticity, CHST11 expression is unleashed, leading to elevated 4-O-sulfated chondroitin levels. Inhibition of the tumor cell CS glycocalyx delays CRPC progression, and impairs growth and motility of prostate cancer after ARPI. Thus, a reactive CS glycocalyx supports adaptive survival and treatment resistance after ARPI, representing a therapeutic opportunity in patients with advanced prostate cancer.

Chondroitin sulfate (CS) is one of the most abundant glycosaminoglycans in prostate cancers. Here the authors show that inhibition of the androgen receptor pathway leads to the upregulation of CS, which promotes prostate cancer growth and metastasis.

Harnessing Human Papillomavirus' Natural Tropism to Target Tumors

Human papillomaviruses (HPV) are small non-enveloped DNA tumor viruses established as the primary etiological agent for the development of cervical cancer. Decades of research have elucidated HPV's primary attachment factor to be heparan sulfate proteoglycans (HSPG). Importantly, wounding and exposure of the epithelial basement membrane was found to be pivotal for efficient attachment and infection of HPV in vivo. Sulfation patterns on HSPG's become modified at the site of wounds as they serve an important role promoting tissue healing, cell proliferation and neovascularization and it is these modifications recognized by HPV. Analogous HSPG modification patterns can be found on tumor cells as they too require the aforementioned processes to grow and metastasize. Although targeting tumor associated HSPG is not a novel concept, the use of HPV to target and treat tumors has only been realized in recent years. The work herein describes how decades of basic HPV research has culminated in the rational design of an HPV-based virus-like infrared light activated dye conjugate for the treatment of choroidal melanoma.

Placental colonization by Fusobacterium nucleatum is mediated by binding of the Fap2 lectin to placentally displayed Gal-GalNAc

While the existence of an indigenous placental microbiota remains controversial, several pathogens are known to be involved in adverse pregnancy outcomes. Fusobacterium nucleatum is an oral bacterium that is one of several bacteria associated with preterm birth. Oral fusobacteria translocate to the placenta hematogenously; however, the mechanisms localizing them to the placenta remain unclear. Here, using peanut agglutinin, we demonstrate that the level of Gal-GalNAc (Galβ1-3GalNAc; Thomsen Friedenreich antigen) found on trophoblasts facing entering maternal blood rises during gestation and is recognized by the fusobacterial Fap2 Gal-GalNAc lectin. F. nucleatum binding to human and mouse placenta correlates with Gal-GalNAc levels and is reduced upon O-glycanase treatment or with soluble Gal-GalNAc. Fap2-inactivated F. nucleatum shows reduced binding to Gal-GalNAc-displaying placental sections. In a mouse model, intravenously injected Fap2-expressing F. nucleatum, but not a Fap2 mutant, reduces mouse fetal survival by 70%.

Internalization and trafficking of CSPG-bound recombinant VAR2CSA lectins in cancer cells

Proteoglycans are proteins that are modified with glycosaminoglycan chains. Chondroitin sulfate proteoglycans (CSPGs) are currently being exploited as targets for drug-delivery in various cancer indications, however basic knowledge on how CSPGs are internalized in tumor cells is lacking. In this study we took advantage of a recombinant CSPG-binding lectin VAR2CSA (rVAR2) to track internalization and cell fate of CSPGs in tumor cells. We found that rVAR2 is internalized into cancer cells via multiple internalization mechanisms after initial docking on cell surface CSPGs. Regardless of the internalization pathway used, CSPG-bound rVAR2 was trafficked to the early endosomes in an energy-dependent manner but not further transported to the lysosomal compartment. Instead, internalized CSPG-bound rVAR2 proteins were secreted with exosomes to the extracellular environment in a strictly chondroitin sulfate-dependent manner. In summary, our work describes the cell fate of rVAR2 proteins in tumor cells after initial binding to CSPGs, which can be further used to inform development of rVAR2-drug conjugates and other therapeutics targeting CSPGs.

Identification and validation of an immune-related gene pairs signature for three urologic cancers

Reliable biomarkers are needed to recognize urologic cancer patients at high risk for recurrence. In this study, we built a novel immune-related gene pairs signature to simultaneously predict recurrence for three urologic cancers. We gathered 14 publicly available gene expression profiles including bladder, prostate and kidney cancer. A total of 2,700 samples were classified into the training set (n = 1,622) and validation set (n = 1,078). The 25 immune-related gene pairs signature consisting of 41 unique genes was developed by the least absolute shrinkage and selection operator regression analysis and Cox regression model. The signature stratified patients into high- and low-risk groups with significantly different relapse-free survival in the meta-training set and its subpopulations, and was an independent prognostic factor of urologic cancers. This signature showed a robust ability in the meta-validation and multiple independent validation cohorts. Immune and inflammatory response, chemotaxis and cytokine activity were enriched with genes relevant to the signature. A significantly higher infiltration level of M1 macrophages was found in the high-risk group versus the low-risk group. In conclusion, our signature is a promising prognostic biomarker for predicting relapse-free survival in patients with urologic cancer.

The role of a drug-loaded poly (lactic co-glycolic acid) (PLGA) copolymer stent in the treatment of ovarian cancer

Objectives: Cisplatin (CDDP) is a widely used and effective basic chemotherapeutic drug for the treatment of a variety of tumors, including ovarian cancer. However, adverse side effects and acquired drug resistance are observed in the clinical application of CDDP. Identifying a mode of administration that can alleviate side effects and reduce drug resistance has become a promising strategy to solve this problem.

Methods: In this study, 3D printing technology was used to prepare a CDDP-poly (lactic-co-glycolic acid) (CDDP-PLGA) polymer compound stent, and its physicochemical properties and cytotoxicity were evaluated both in vitro and in vivo.

Results: The CDDP-PLGA stent had a significant effect on cell proliferation and apoptosis and clearly decreased the size of subcutaneous tumors in nude mice, whereas the systemic side effects were mild compared with those of intraperitoneal CDDP injection. Compared with the control group, CDDP-PLGA significantly increased the mRNA and protein levels of p-glycoprotein (P < 0.01; P < 0.01) and decreased vascular endothelial growth factor mRNA (P < 0.05) and protein levels (P < 0.01), however, CDDP-PLGA significantly decreased the mRNA and protein levels of p-glycoprotein (P < 0.01; P < 0.01) and vascular endothelial growth factor (P < 0.01; P < 0.01), which are associated with chemoresistance, in subcutaneous tumor tissue. Immunohistochemistry assay results revealed that, in the CDDP-PLGA group, the staining of the proliferation-related genes Ki67 and PCNA were lightly, and the apoptosis-related gene caspase-3 stained deeply.

Conclusions: PLGA biomaterials loaded with CDDP, as compared with the same amount of free CDDP, showed good efficacy in terms of cytotoxicity, as evidenced by changes in apoptosis. Continuous local CDDP release can decrease the systemic side effects of this drug and the occurrence of drug resistance and angiogenesis, and improve the therapeutic effect. This new approach may be an effective strategy for the local treatment of epithelial ovarian cancer.

Oncofetal Chondroitin Sulfate Is a Highly Expressed Therapeutic Target in Non-Small Cell Lung Cancer

Broad-spectrum therapeutics in non-small cell lung cancer (NSCLC) are in demand. Most human solid tumors express proteoglycans modified with distinct oncofetal chondroitin sulfate (CS) chains that can be detected and targeted with recombinant VAR2CSA (rVAR2) proteins and rVAR2-derived therapeutics. Here, we investigated expression and targetability of oncofetal CS expression in human NSCLC. High oncofetal CS expression is associated with shorter disease-free survival and poor overall survival of clinically annotated stage I and II NSCLC patients (n = 493). Oncofetal CS qualifies as an independent prognosticator of NSCLC in males and smokers, and high oncofetal CS levels are more prevalent in EGFR/KRAS wild-type cases, as compared to mutation cases. NSCLC cell lines express oncofetal CS-modified proteoglycans that can be specifically detected and targeted by rVAR2 proteins in a CSA-dependent manner. Importantly, a novel VAR2-drug conjugate (VDC-MMAE) efficiently eliminates NSCLC cells in vitro and in vivo. In summary, oncofetal CS is a prognostic biomarker and an actionable glycosaminoglycan target in NSCLC.

Evaluation of carbonic anhydrase IX as a potential therapeutic target in urothelial carcinoma

OBJECTIVE

Carbonic anhydrase IX (CA9) is important in the regulation of intra- and extracellular pH in solid tumors, contributing to cell growth and invasion. In urothelial carcinoma (UC), CA9 has been identified as a urinary marker for disease detection, but its biologic role is unknown. To date, differential gene expression patterns of CA9 in various molecular subtypes and potential effects of CA9 inhibition in UC cells are unknown. We aimed to investigate the function of CA9 and the effects of CA9 inhibition in invasive UC.

METHODS

Immunohistochemistry was used to assess CA9 expression in a cohort of 153 patients undergoing radical cystectomy. CA9 expression was correlated with molecular subtype by analysis of the TCGA data and of our own cohort of 223 patients with invasive UC receiving neoadjuvant chemotherapy. CA9 expression was assessed in a panel of 12 UC cell lines by Western Blot and qPCR, and multiple siRNAs were used to silence CA9 in 2 cell lines. Effects of CA9 silencing on cell growth, migration, and invasion were assessed. We also used the small molecule inhibitor U-104 to inhibit CA9 in vitro and in an orthotopic xenograft model.

RESULTS

CA9 expression was higher in cancer tissue compared to benign urothelium and was particularly highly expressed in luminal papillary and basal squamous tumors. CA9 expression did not correlate with outcome after neoadjuvant chemotherapy and/or radical cystectomy. Silencing of CA9 by siRNA diminished invasion but did not induce a consistent change of cell growth and migration. Treatment with U-104 led to cell growth reduction only at high concentrations in vitro and failed to have a significant effect on tumor growth in vivo.

CONCLUSIONS

The present study confirms over-expression of CA9 in UC and for the first time shows a correlation with molecular subtypes. However, CA9 expression showed no association with the outcome of patients with muscle invasive bladder cancer and inhibition of CA9 did not lead to a consistent inhibition of tumor growth. Based on these data, CA9 exhibits a role neither as a predictive or prognostic marker nor as a therapeutic target in invasive UC.

Cryo-EM reveals the architecture of placental malaria VAR2CSA and provides molecular insight into chondroitin sulfate binding

Placental malaria can have severe consequences for both mother and child and effective vaccines are lacking. Parasite-infected red blood cells sequester in the placenta through interaction between parasite-expressed protein VAR2CSA and the glycosaminoglycan chondroitin sulfate A (CS) abundantly present in the intervillous space. Here, we report cryo-EM structures of the VAR2CSA ectodomain at up to 3.1 Å resolution revealing an overall V-shaped architecture and a complex domain organization. Notably, the surface displays a single significantly electropositive patch, compatible with binding of negatively charged CS. Using molecular docking and molecular dynamics simulations as well as comparative hydroxyl radical protein foot-printing of VAR2CSA in complex with placental CS, we identify the CS-binding groove, intersecting with the positively charged patch of the central VAR2CSA structure. We identify distinctive conserved structural features upholding the macro-molecular domain complex and CS binding capacity of VAR2CSA as well as divergent elements possibly allowing immune escape at or near the CS binding site. These observations will support rational design of second-generation placental malaria vaccines.

In placental malaria, interactions between parasite protein VAR2CSA and human glycosaminoglycan chondroitin sulfate A (CS) sequesters infected red blood cells in the placenta. Here, the authors provide cryo-EM structures of VAR2CSA and placental CS, identifying molecular interactions that could guide design of placental malaria vaccines.

Development of a bispecific immune engager using a recombinant malaria protein

As an immune evasion and survival strategy, the Plasmodium falciparum malaria parasite has evolved a protein named VAR2CSA. This protein mediates sequestration of infected red blood cells in the placenta through the interaction with a unique carbohydrate abundantly and exclusively present in the placenta. Cancer cells were found to share the same expression of this distinct carbohydrate, termed oncofetal chondroitin sulfate on their surface. In this study we have used a protein conjugation system to produce a bispecific immune engager, V-aCD3, based on recombinant VAR2CSA as the cancer targeting moiety and an anti-CD3 single-chain variable fragment linked to a single-chain Fc as the immune engager. Conjugation of these two proteins resulted in a single functional moiety that induced immune mediated killing of a broad range of cancer cells in vitro and facilitated tumor arrest in an orthotopic bladder cancer xenograft model.

Differences of the tumour cell glycocalyx affect binding of capsaicin-loaded chitosan nanocapsules

The glycocalyx regulates the interaction of mammalian cells with extracellular molecules, such as cytokines. However, it is unknown to which extend the glycocalyx of distinct cancer cells control the binding and uptake of nanoparticles. In the present study, exome sequencing data of cancer patients and analysis of distinct melanoma and bladder cancer cell lines suggested differences in cancer cell-exposed glycocalyx components such as heparan sulphate. Our data indicate that glycocalyx differences affected the binding of cationic chitosan nanocapsules (Chi-NCs). The pronounced glycocalyx of bladder cancer cells enhanced the internalisation of nanoencapsulated capsaicin. Consequently, capsaicin induced apoptosis in the cancer cells, but not in the less glycosylated benign urothelial cells. Moreover, we measured counterion condensation on highly negatively charged heparan sulphate chains. Counterion condensation triggered a cooperative binding of Chi-NCs, characterised by a weak binding rate at low Chi-NC doses and a strongly increased binding rate at high Chi-NC concentrations. Our results indicate that the glycocalyx of tumour cells controls the binding and biological activity of nanoparticles. This has to be considered for the design of tumour cell directed nanocarriers to improve the delivery of cytotoxic drugs. Differential nanoparticle binding may also be useful to discriminate tumour cells from healthy cells.

Soluble Syndecan-1 Levels Are Associated with Survival in Platinum-Treated Bladder Cancer Patients

Cisplatin-containing chemotherapy represents the first-line treatment for patients with locally advanced or metastatic muscle-invasive bladder cancer. Recently, novel therapies have become available for cisplatin-ineligible or -resistant patients. Therefore, prediction of cisplatin response is required to optimize therapy decisions. Syndecan-1 (SDC1) tissue expression and serum concentration may be associated with cisplatin resistance. Thus, pre-treatment serum levels of SDC1 and its expression in chemo-naïve tissues were assessed in 121 muscle-invasive bladder cancer patients who underwent postoperative platinum-based chemotherapy. SDC1 concentrations were evaluated by ELISA in 52 baseline and 90 follow-up serum samples and tissue expressions were analyzed by immunohistochemistry in an independent cohort of 69 formalin-fixed paraffin-embedded tumor samples. Pre-treatment SDC1 serum levels were significantly higher in lymph node metastatic (p = 0.009) and female patients (p = 0.026). SDC1 tissue expression did not correlate with clinicopathological parameters. High pre-treatment SDC1 serum level and the presence of distant metastasis were independent risk factors for overall survival (Hazard ratio (HR): 1.439, 95% Confidence interval (CI): 1.003–2.065, p = 0.048; HR: 2.269, 95%CI: 1.053–4.887, p = 0.036). Our results demonstrate an independent association between high baseline serum SDC1 concentration and poor survival in platinum-treated patients. Analyzing baseline serum SDC1 levels may help to predict platinum-containing chemotherapy and could help to optimize therapeutic decision-making.

A simple method for detecting oncofetal chondroitin sulfate glycosaminoglycans in bladder cancer urine

Proteoglycans in bladder tumors are modified with a distinct oncofetal chondroitin sulfate (ofCS) glycosaminoglycan that is normally restricted to placental trophoblast cells. This ofCS-modification can be detected in bladder tumors by the malarial VAR2CSA protein, which in malaria pathogenesis mediates adherence of parasite-infected erythrocytes within the placenta. In bladder cancer, proteoglycans are constantly shed into the urine, and therefore have the potential to be used for detection of disease. In this study we investigated whether recombinant VAR2CSA (rVAR2) protein could be used to detect ofCS-modified proteoglycans (ofCSPGs) in the urine of bladder cancer patients as an indication of disease presence. We show that ofCSPGs in bladder cancer urine can be immobilized on cationic nitrocellulose membranes and subsequently probed for ofCS content by rVAR2 protein in a custom-made dot-blot assay. Patients with high-grade bladder tumors displayed a marked increase in urinary ofCSPGs as compared to healthy individuals. Urine ofCSPGs decreased significantly after complete tumor resection compared to matched urine collected preoperatively from patients with bladder cancer. Moreover, ofCSPGs in urine correlated with tumor size of bladder cancer patients. These findings demonstrate that rVAR2 can be utilized in a simple biochemical assay to detect cancer-specific ofCS-modifications in the urine of bladder cancer patients, which may be further developed as a noninvasive approach to detect and monitor the disease.

Epigenetic profiling demarcates molecular subtypes of muscle-invasive bladder cancer

Muscle-invasive bladder cancer (MIBC) is a heterogeneous disease that often recurs despite aggressive treatment with neoadjuvant chemotherapy and (radical) cystectomy. Basal and luminal molecular subtypes have been identified that are linked to clinical characteristics and have differential sensitivities to chemotherapy. While it has been suggested that epigenetic mechanisms play a role in defining these subtypes, a thorough understanding of the biological mechanisms is lacking. This report details the first genome-wide analysis of histone methylation patterns of human primary bladder tumours by chromatin immunoprecipitations and next-generation sequencing (ChIP-seq). We profiled multiple histone marks: H3K27me3, a marker for repressed genes, and H3K4me1 and H3K4me3, which are indicators of active enhancers and active promoters. Integrated analysis of ChIP-seq data and RNA sequencing revealed that H3K4 mono-methylation demarcates MIBC subtypes, while no association was found for the other two histone modifications in relation to basal and luminal subtypes. Additionally, we identified differentially methylated H3K4me1 peaks in basal and luminal tumour samples, suggesting that active enhancers play a role in defining subtypes. Our study is the first analysis of histone modifications in primary bladder cancer tissue and provides an important resource for the bladder cancer community.

Optimization of rVAR2-Based Isolation of Cancer Cells in Blood for Building a Robust Assay for Clinical Detection of Circulating Tumor Cells

Early detection and monitoring of cancer progression is key to successful treatment. Therefore, much research is invested in developing technologies, enabling effective and valuable use of non-invasive liquid biopsies. This includes the detection and analysis of circulating tumor cells (CTCs) from blood samples. Recombinant malaria protein VAR2CSA (rVAR2) binds a unique chondroitin sulfate modification present on the vast majority of cancers and thereby holds promise as a near-universal tumor cell-targeting reagent to isolate CTCs from complex blood samples. This study describes a technical approach for optimizing the coupling of rVAR2 to magnetic beads and the development of a CTC isolation platform targeting a range of different cancer cell lines. We investigate both direct and indirect approaches for rVAR2-mediated bead retrieval of cancer cells and conclude that an indirect capture approach is most effective for rVAR2-based cancer cell retrieval.

Oncofetal Chondroitin Sulfate: A Putative Therapeutic Target in Adult and Pediatric Solid Tumors

Solid tumors remain a major challenge for targeted therapeutic intervention strategies such as antibody-drug conjugates and immunotherapy. At a minimum, clear and actionable solid tumor targets have to comply with the key biological requirement of being differentially over-expressed in solid tumors and metastasis, in contrast to healthy organs. Oncofetal chondroitin sulfate is a cancer-specific secondary glycosaminoglycan modification to proteoglycans expressed in a variety of solid tumors and metastasis. Normally, this modification is found to be exclusively expressed in the placenta, where it is thought to facilitate normal placental implantation during pregnancy. Informed by this biology, oncofetal chondroitin sulfate is currently under investigation as a broad and specific target in solid tumors. Here, we discuss oncofetal chondroitin sulfate as a potential therapeutic target in childhood solid tumors in the context of current knowhow obtained over the past five years in adult cancers.

Silencing of lncRNA XIST inhibits non-small cell lung cancer growth and promotes chemosensitivity to cisplatin

Long noncoding RNAs (lncRNAs) play critical roles in tumour progression and metastasis. Emerging evidence indicates that the lncRNA X inactive-specific transcript (XIST) is dysregulated in several tumor types, including non-small cell lung cancer (NSCLC). However, in NSCLC and other cancers the oncogenic mechanism of XIST remains incompletely understood. Here, we confirmed that XIST is upregulated in human NSCLC specimens, and is especially overexpressed in tumors previously treated with cisplatin (cis-diamminedichloroplatinum(II); DDP). In vitro, XIST knockdown inhibited NSCLC cell growth and promoted DDP chemosensitivity by stimulating apoptosis and pyroptosis. Moreover, XIST's oncogenic effects and ability to promote DDP chemoresistance were largely related to its binding to the TGF-β effector SMAD2, which inhibited its translocation to the nucleus and prevented the transcription of p53 and NLRP3, crucial regulators of apoptosis and pyroptosis, respectively. Using DDP-resistant NSCLC cells, mouse xenograft studies verified the oncogenic function of XIST and its ability to inhibit programmed cell death, thereby mediating DDP chemoresistance. These findings suggest that XIST expression may serve as a novel biomarker to predict DDP treatment efficacy, and may help in the design of new therapies to circumvent DDP chemoresistance in NSCLC and other tumor types.

Ramucirumab plus docetaxel versus placebo plus docetaxel in patients with locally advanced or metastatic urothelial carcinoma after platinum-based therapy (RANGE): overall survival and updated results of a randomised, double-blind, phase 3 trial

BACKGROUND

Ramucirumab-an IgG1 vascular endothelial growth factor receptor 2 antagonist-plus docetaxel was previously reported to improve progression-free survival in platinum-refractory, advanced urothelial carcinoma. Here, we report the secondary endpoint of overall survival results for the RANGE trial.

METHODS

We did a randomised, double-blind, phase 3 trial in patients with advanced or metastatic urothelial carcinoma who progressed during or after platinum-based chemotherapy. Patients were enrolled from 124 investigative sites (hospitals, clinics, and academic centres) in 23 countries. Previous treatment with one immune checkpoint inhibitor was permitted. Patients were randomly assigned (1:1) using an interactive web response system to receive intravenous ramucirumab 10 mg/kg or placebo 10 mg/kg volume equivalent followed by intravenous docetaxel 75 mg/m2 (60 mg/m2 in Korea, Taiwan, and Japan) on day 1 of a 21-day cycle. Treatment continued until disease progression, unacceptable toxicity, or other discontinuation criteria were met. Randomisation was stratified by geographical region, Eastern Cooperative Oncology Group performance status at baseline, and visceral metastasis. Progression-free survival (the primary endpoint) and overall survival (a key secondary endpoint) were assessed in the intention-to-treat population. The study is registered with ClinicalTrials.gov, NCT02426125; patient enrolment is complete and the last patient on treatment is being followed up for safety issues.

FINDINGS

Between July 20, 2015, and April 4, 2017, 530 patients were randomly allocated to ramucirumab plus docetaxel (n=263) or placebo plus docetaxel (n=267) and comprised the intention-to-treat population. At database lock (March 21, 2018) for the final overall survival analysis, median follow-up was 7·4 months (IQR 3·5-13·9). In our sensitivity analysis of investigator-assessed progression-free survival at the overall survival database lock, median progression-free survival remained significantly improved with ramucirumab compared with placebo (4·1 months [95% CI 3·3-4·8] vs 2·8 months [2·6-2·9]; HR 0·696 [95% CI 0·573-0·845]; p=0·0002). Median overall survival was 9·4 months (95% CI 7·9-11·4) in the ramucirumab group versus 7·9 months (7·0-9·3) in the placebo group (stratified HR 0·887 [95% CI 0·724-1·086]; p=0·25). Grade 3 or worse treatment-related treatment-emergent adverse events in 5% or more of patients and with an incidence more than 2% higher with ramucirumab than with placebo were febrile neutropenia (24 [9%] of 258 patients in the ramucirumab group vs 16 [6%] of 265 patients in the placebo group) and neutropenia (17 [7%] of 258 vs six [2%] of 265). Serious adverse events were similar between groups (112 [43%] of 258 patients in the ramucirumab group vs 107 [40%] of 265 patients in the placebo group). Adverse events related to study treatment and leading to death occurred in eight (3%) patients in the ramucirumab group versus five (2%) patients in the placebo group.

INTERPRETATION

Additional follow-up supports that ramucirumab plus docetaxel significantly improves progression-free survival, without a significant improvement in overall survival, for patients with platinum-refractory advanced urothelial carcinoma. Clinically meaningful benefit might be restricted in an unselected population.

FUNDING

Eli Lilly and Company.

STIP1 Tissue Expression Is Associated with Survival in Chemotherapy-Treated Bladder Cancer Patients

To optimize treatment decisions in advanced bladder cancer (BC), we aimed to assess the therapy predictive value of STIP1 with regard to cisplatin therapy. Cisplatin-based chemotherapy represents the standard first-line systemic treatment of advanced bladder cancer. Since novel immunooncologic agents are already available for cisplatin-resistant or ineligible patients, biological markers are needed for the prediction of cisplatin resistance. STIP1 expression was analyzed in paraffin-embedded bladder cancer tissue samples of 98 patients who underwent adjuvant or salvage cisplatin-based chemotherapy by using immunohistochemistry. Furthermore, pre-chemotherapy serum STIP1 concentrations were determined in 48 BC patients by ELISA. Results were correlated with the clinicopathological and follow-up data. Stronger STIP1 nuclear staining was associated with worse OS in both the whole patient group (p = 0.034) and the subgroup of patients who received at least 2 cycles of chemotherapy (p = 0.043). These correlations remained significant also in the multivariable analyses (p = 0.035 and p = 0.040). Stronger STIP1 cytoplasmatic immunostaining correlated with shorter PFS both in the whole cohort (p = 0.045) and in the subgroup of patients who received at least 2 cycles of chemotherapy (p = 0.026). Elevated STIP1 serum levels were associated with older patient's age, but we found no correlation between STIP1 serum levels and patients' outcome. Our results suggest that tissue STIP1 analysis might be used for the prediction of cisplatin-resistance in BC. In contrast, pretreatment STIP1 serum levels showed no predictive value for chemotherapy response and survival.

Inhibition of GLI2 with antisense-oligonucleotides: A potential therapy for the treatment of bladder cancer

The sonic hedgehog (SHH) signaling pathway plays an integral role in the maintenance and progression of bladder cancer (BCa) and SHH inhibition may be an efficacious strategy for BCa treatment. We assessed an in-house human BCa tissue microarray and found that the SHH transcription factors, GLI1 and GLI2, were increased in disease progression. A panel of BCa cell lines show that two invasive lines, UM-UC-3 and 253J-BV, both express these transcription factors but UM-UC-3 produces more SHH ligand and is less responsive in viability to pathway stimulation by recombinant human SHH or smoothened agonist, and less responsive to inhibitors including the smoothened inhibitors cyclopamine and SANT-1. In contrast, 253J-BV was highly responsive to these manipulations. We utilized a GLI1 and GLI2 antisense oligonucleotide (ASO) to bypass pathway mechanics and target the transcription factors directly. UM-UC-3 decreased in viability due to both ASOs but 253J-BV was only affected by GLI2 ASO. We utilized the murine intravesical orthotopic human BCa (mio-hBC) model for the establishment of noninvasive BCa and treated tumors with GLI2 ASO. Tumor size, growth rate, and GLI2 messenger RNA and protein expression were decreased. These results suggest that GLI2 ASO may be a promising new targeted therapy for BCa.

Editorial: Basic research in bladder cancer - refining the tools. 3rd IBCN seminars series1

This editorial highlights submissions to part II of the 3rd IBCN Seminars Series particularly focusing on the tools required for conduction of translational research in bladder cancer. One of the submissions describe the ex vivo culture of primary tumor cells from N-methyl-N-nitrosourea-induced bladder tumors in rats and subsequent establishment of an immortalized cell line. In a next step the authors thoroughly characterize this cell line. They conclude that differentiation marker expression patterns observed in the original tumors are largely retained in the spheroids. Although new cancer models, such as organoid tissue cultures, hold great promise for studying cancer progression and might have a potential for development and selection of an optimal treatment, their limitations must be kept in mind. The second submission, therefore, critically questions the current role of organoid tissue culture as a predictive tool in urothelial cancer patients. The third manuscript of this series provides a broader overview of post-translational modification in bladder cancer is presented and how PTMs can be exploited as potential therapeutic targets. The 3 manuscripts featured in this issue demonstrate especially how basic research is being channeled to inform clinically actionable discoveries.

Effective loading of cisplatin into a nanoscale UiO-66 metal-organic framework with preformed defects

Defects within the nanoscale UiO-66 metal-organic framework (MOF) are created to lock a hybrid phosphonoacetate ligand through Zr-O-P linkages, leaving the carboxyl group free to anchor cisplatin prodrug cis, cis, trans-[Pt(NH3)2Cl2(OH)2]. A drug loading of 256.5 mg g-1 (25.7 wt% based on cisplatin) was achieved with a Zr6 : Pt : P ratio of 1.5 : 1 : 1, which surpasses defect-free UiO-66 and several other MOF carriers. This framework exhibited a burst release of its payload in PBS solution in the first 2 h, releasing 71% of the drug, including a 50% payload release in less than 1 h. This work demonstrates that MOF defects can be intentionally engineered to achieve a high drug loading, and serves as an alternative to drug encapsulation using the pore void and through the association of the functionalized ligand.

Post-translational modifications in bladder cancer: Expanding the tumor target repertoire

Over the past decade, genomic and transcriptomic analyses have uncovered promising tumor antigens including immunotherapeutic targets in bladder cancer (BCa). Conventional tumor antigens are proteins expressed on the plasma membrane of tumor cells such as EGFR, FGFR3, and ERBB2 in BCa, which can be targeted by antibodies or similar epitope-specific binding reagents. The cellular proteome consists of ∼100,000 proteins but the expression of these proteins is rarely unique to tumor cells. Many tumor-associated proteins are post-translationally modified with phosphorylation, glycosylation, ubiquitination, or SUMOylation moieties. Although these modifications expand the complexity, they potentially offer novel targeting opportunities across tumor sub-populations. Experimental targeting of cancer-specific post-translational modifications (PTMs) has shown encouraging results in pre-clinical models of BCa, which could potentially overcome issues with inherent intra-tumor heterogeneity due to simultaneous expression on different proteins. Here, we review current knowledge on post-translational modifications in BCa and highlight recent efforts in experimental targeting strategies.

Overexpression of Epidermal Growth Factor Receptor (EGFR) and HER-2 in Bladder Carcinoma and Its Association with Patients' Clinical Features

BACKGROUND The aim of this study was to determine the expression of EGFR/HER-2 and investigate their association with patients' clinical features in bladder transitional cell carcinoma (BTCC). MATERIAL AND METHODS Immunohistochemistry was utilized in our study to explore the expression of EGFR/HER-2 of 56 human bladder cancer samples and 10 normal bladder samples. RESULTS EGFR and HER-2 expressions were both significantly higher in bladder transitional cell carcinoma (BTCC) than that in non-cancer bladder samples; the EGFR positivity rate was 55.4% among BTCC samples and 37.5% for HER-2a. A statistically significant correlation was also present between the increasing EGFR or HER-2 expression levels and the clinical stages, pathologic grades, and tumor recurrence. The expression level of EGFR increased along with higher clinical stages and pathologic grades of BTCC, and the obviously increased expression of HER-2 was statistically associated with clinical stages and tumor recurrence. In addition, the expression level of HER-2 increased along with the higher clinical stage of BTCC. EGFR expression and HER-2 levels were positively associated in BTCC samples. CONCLUSIONS Our findings demonstrate that high EGFR and HER-2 expressions are dramatically increased in the BTCC tissues and are closely related to the clinical stages, pathologic grades, and tumor recurrence. Therefore, the evaluation of EGFR and HER-2 expression in BTCC may contribute to identifying patients who are at increased risk of disease progression and recurrence.

Synthesis and Characterization of Placental Chondroitin Sulfate A (plCSA)-Targeting Lipid-Polymer Nanoparticles

An effective cancer therapeutic method reduces and eliminates tumors with minimal systemic toxicity. Actively targeting nanoparticles offer a promising approach to cancer therapy. The glycosaminoglycan placental chondroitin sulfate A (plCSA) is expressed on a wide range of cancer cells and placental trophoblasts, and malarial protein VAR2CSA can specifically bind to plCSA. A reported placental chondroitin sulfate A binding peptide (plCSA-BP), derived from malarial protein VAR2CSA, can also specifically bind to plCSA on cancer cells and placental trophoblasts. Hence, plCSA-BP-conjugated nanoparticles could be used as a tool for targeted drug delivery to human cancers and placental trophoblasts. In this protocol, we describe a method to synthesize plCSA-BP-conjugated lipid-polymer nanoparticles loaded with doxorubicin (plCSA-DNPs); the method consists of a single sonication step and bioconjugate techniques. In addition, several methods for characterizing plCSA-DNPs, including determining their physicochemical properties and cellular uptake by placental choriocarcinoma (JEG3) cells, are described.

The VAR2CSA malaria protein efficiently retrieves circulating tumor cells in an EpCAM-independent manner

Isolation of metastatic circulating tumor cells (CTCs) from cancer patients is of high value for disease monitoring and molecular characterization. Despite the development of many new CTC isolation platforms in the last decade, their isolation and detection has remained a challenge due to the lack of specific and sensitive markers. In this feasibility study, we present a method for CTC isolation based on the specific binding of the malaria rVAR2 protein to oncofetal chondroitin sulfate (ofCS). We show that rVAR2 efficiently captures CTCs from hepatic, lung, pancreatic, and prostate carcinoma patients with minimal contamination of peripheral blood mononuclear cells. Expression of ofCS is present on epithelial and mesenchymal cancer cells and is equally preserved during epithelial–mesenchymal transition of cancer cells. In 25 stage I–IV prostate cancer patient samples, CTC enumeration significantly correlates with disease stage. Lastly, rVAR2 targets a larger and more diverse population of CTCs compared to anti-EpCAM strategies.

Isolation of circulating tumor cells (CTCs) allows for non-invasive disease monitoring and characterization. Here the authors describe an alternative CTC isolation method based on the ability of the malaria rVAR2 protein to specifically bind oncofetal chondroitin sulfate, which is expressed by all cancer cells

Targeted delivery of doxorubicin by CSA-binding nanoparticles for choriocarcinoma treatment

Gestational trophoblastic neoplasia (GTN) can result from the over-proliferation of trophoblasts. Treatment of choriocarcinoma, the most aggressive GTN, currently requires high doses of systemic chemotherapeutic agents, which result in indiscriminate drug distribution and severe toxicity. To overcome these disadvantages and enhance the chemotherapeutic efficacy, chondroitin sulfate A (CSA)-binding nanoparticles were developed for the targeted delivery of doxorubicin (DOX) to choriocarcinoma cells using a synthetic CSA-binding peptide (CSA-BP), derived from malarial protein, which specifically binds to the CSA exclusively expressed in the placental trophoblast. CSA-BP-conjugated nanoparticles rapidly bonded to choriocarcinoma (JEG3) cells and were efficiently internalized into the lysosomes. Moreover, CSA-BP modification significantly increased the anti-cancer activity of the DOX-loaded nanoparticles in vitro. Intravenous injections of CSA-BP-conjugated nanoparticles loaded with indocyanine green (CSA-INPs) were rapidly localized to the tumor. The CSA-targeted nanoparticles loaded with DOX (CSA-DNPs) strongly inhibited primary tumor growth and, more importantly, significantly suppressed metastasis in vivo. Collectively, our results highlight the potential of the CSA-BP-decorated nanoparticles as an alternative targeted delivery system of chemotherapeutic agents for treating choriocarcinoma and for developing new GTN therapies based on drug targeting.

Different stages in drug development for muscle-invasive bladder cancer

Muscle-invasive bladder cancer (MIBC) is a highly aggressive disease. Despite optimal therapy, half of the patients will succumb to disease. This prognosis could not be improved over the last three decades. Therefore, MIBC is left behind from other cancers such as prostate, where novel treatment options were discovered and improve patient outcomes. While being aware of the recent emerging evidence of checkpoint inhibition in MIBC, we aim to describe different stages of drug development in MIBC by using three specific targets. On the example of Her2 targeting, we aimed to indicate, that either a target is ineffective in MIBC or that the patient selection is insufficient. The first clinical trials using a pan fibroblast growth factor receptor (panFGFR) inhibitor to target the FGFR pathway showed promising results. Data of further trials are to be awaited before implementing these drugs into daily clinical practice. A large variety of novel agents are investigated in vitro and in vivo. On the example of a malaria protein, we aimed to discuss a treatment paradigm that is not dependent on pathway signaling and the genomic landscape of MIBC. The ultimate question still remains to be answered: How do we select the optimal treatment for the right patient?