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PURPOSE Data quality and standardization remain a challenge when analyzing real-world clinical data. We built a clinical research database, using machine learning and natural learning processing, and investigated factors influencing testosterone recovery (T-recovery) in patients with localized prostate cancer (LPC) after initial androgen deprivation therapy (ADT). METHODS Medication and treatment-associated dates missing in structured tables were extracted from patient notes using ConceptMapper, an automated data extraction tool, standardized and curated in Sema4 clinical research database. ADT usage duration was evaluated, and T-recovery in patients with LPC was analyzed by the Kaplan-Meier method and multivariable Cox proportional hazards models. We assessed the prognostic value of post-ADT T-recovery with prostate-specific antigen progression-free survival and failure-free survival. RESULTS In total, 4,125 of 30,832 (13.4%) patients with prostate cancer had medication exclusively from notes with high precision and recall, F1 score ≥ 0.95. Association of dates with medication usage had a F1 score of 0.76. ADT duration estimation had higher accuracy combining information from notes to tables from electronic medical record (70% v 45%). Baseline testosterone was the strongest predictor of T-recovery in these patients. Patients with a baseline testosterone ≥ 300 ng/dL recovered in 9.79 versus 38 months for patients with baseline testosterone < 300 ng/dL ( P < .0001). Shorter prostate-specific antigen progression-free interval was observed for patients with T-recovery (≥ 300 ng/dL) at 6 months after ADT cessation compared with patients without T-recovery (< 300 ng/dL; 13.7 v 25.1 months; P = .055). CONCLUSION We augmented structured electronic medical record data with data extracted from notes and improved the accuracy of medication information for patients. ADT exposure and T-recovery in patients with LPC produced results consistent with the literature and clinical experience and illustrates the power of applying machine learning methods to enhance the quality of real-world evidence in answering clinically relevant questions.

Supplementary Figure 1. Co-immuoprecipitation of RhoGDI2 with RhoC in non-bladder cell types Endogenous RhoGDI2 from MDA-MB-231 breast cancer cells (Left), Jurkat lymphocyte cells (Center), or OVCAR-4 ovarian cancer cells (Right) was immunoprecipitated and analyzed by western blot for co-immunoprecipitation of Rac1 and RhoC. Representative western blots of 3 independent experiments shown.

Supplementary Table 2. Differential expression of RhoC/RhoGDI2 signature genes

Supplementary Figure and Table Legends. Legends for 3 supplemental figures and 2 tables.

Supplementary Figure 3. Depletion of RhoC with a second independent shRNA A. Doubling time for T24T cells expressing shCont or shRhoC-2 was determined by counting cells at 24 h intervals for 96 h. Bargraph shows the mean doubling time{plus minus}s.e. (n=3). *P

Clinicopathologic characteristics of bladder cancer patient samples in microarray datasets

Supplemental Figure Legends

List of all differentially regulated probes with AGL loss in UMUC3 bladder cancer cells at FDR at 2%.

Multivariable analysis corresponding to Figure 6C (iii)

Purpose: We demonstrated that amylo-alpha-1-6-glucosidase-4-alpha-glucanotransferase (AGL) is a tumor growth suppressor and prognostic marker in human bladder cancer. Here we determine how AGL loss enhances tumor growth, hoping to find therapeutically tractable targets/pathways that could be used in patients with low AGL–expressing tumors.Experimental Design: We transcriptionally profiled bladder cell lines with different AGL expression. By focusing on transcripts overexpressed as a function of low AGL and associated with adverse clinicopathologic variables in human bladder tumors, we sought to increase the chances of discovering novel therapeutic opportunities.Results: One such transcript was hyaluronic acid synthase 2 (HAS2), an enzyme responsible for hyaluronic acid (HA) synthesis. HAS2 expression was inversely proportional to that of AGL in bladder cancer cells and immortalized and normal urothelium. HAS2-driven HA synthesis was enhanced in bladder cancer cells with low AGL, and this drove anchorage-dependent and independent growth. siRNA-mediated depletion of HAS2 or inhibition of HA synthesis by 4-methylumbelliferone (4MU) abrogated in vitro and xenograft growth of bladder cancer cells with low AGL. AGL and HAS2 mRNA expression in human tumors was inversely correlated in patient datasets. Patients with high HAS2 and low AGL tumor mRNA expression had poor survival, lending clinical support to xenograft findings that HAS2 drives growth of tumors with low AGL.Conclusions: Our study establishes HAS2-mediated HA synthesis as a driver of growth of bladder cancer with low AGL and provides preclinical rationale for personalized targeting of HAS2/HA signaling in patients with low AGL–expressing tumors. Clin Cancer Res; 22(5); 1274–83. ©2015 AACR.

Supplemental Figure 1. Heatmap for top 100 differentially expressed genes with AGL depletion in bladder cancer cell line UMUC3. Supplemental Figure 2. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) for HAS2, RRAGD, VCAN, EREG and TULP3 in T24T cells with or without AGL. Supplemental Figure 3. A,B,C, Monolayer growth of UMUC3 cells with and without AGL knockdown followed by knockdown of HAS2, RRAGD and TULP3. Supplemental Figure 4. A, qRT-PCR for HAS2 in UMUC3 control and AGL knockdown cells using a second siRNA against HAS2 followed by monolayer growth assay. B, qRT-PCR for HAS2 in MGHU4 cells with AGL knockdown. C, qRT-PCR to validate knockdown of HAS2 in MGHU4 control and AGL knockdown cells followed by monolayer growth assay. Supplemental Figure 5. A, HA ELISA for UMUC3 AGL knockdown cells after knockdown of HAS2 using a new siRNA. B, HA ELISA of MGHU4 cells with or without AGL expression after HAS2 knockdown. C, Monolayer growth of T24T cells with and without AGL on treatment with 4MU. D, Monolayer growth of T24T cells with and without AGL on treatment with 4MU and HA.

Multivariable analysis corresponding to Figures 6C (i) and (ii)

BackgroundUntil recently there were no genome-directed therapies (GDTs) requiring next-generation sequencing (NGS) in prostate cancer. We examined whether the US approval of poly-(ADP-ribose) polymerase (PARP) inhibitors in May 2020 influenced the actionability and utilization of NGS in patients with prostate cancer.MethodsThis was a single-center, retrospective study including men with prostate cancer who received NGS testing from a single lab between 7/11/2018-7/6/2021. Clinical and testing data were derived from the electronic medical record.ResultsThere were 346 patients with prostate cancer and qualifying NGS testing during the study period. Overall, 55 patients (15.9%) had qualifying homologous recombination repair (HRR) alterations for PARP inhibitor treatment. A greater proportion of alterations were actionable post-approval compared to pre-approval (22.7% vs 0%, Chi-squared pConclusionIn this single-center cohort, the approval of PARP inhibitors for later-line treatment of metastatic prostate cancer increased the actionability of NGS findings but did not lead to earlier use of NGS testing.

Introduction Historically, high rates of actionable driver mutations have been reported in never-smokers with lung adenocarcinoma (ADC). In the era of modern, comprehensive cancer mutation sequencing, this relationship necessitates a more detailed analysis. Methods All Mount Sinai patients between January 1, 2015, and June 1, 2020, with a diagnosis of ADC of any stage with known smoking status who received genomic testing were included. Most patients were analyzed using the Sema4 hotspot panel or the Oncomine Comprehensive Assay version 3 next-generation sequencing (NGS) panel conducted at Sema4. Patients were considered fully genotyped if they were comprehensively analyzed for alterations in EGFR, KRAS, MET, ALK, RET, ROS1, BRAF, NTRK1-3, and ERBB2, otherwise they were considered partially genotyped. Results Two hundred and thirty-six never-smokers and 671 smokers met the above criteria. Of the never-smokers, 201 (85%) had a driver mutation with 167 (71%) considered actionable (ie, those with US Food and Drug Administration-approved agents). Among smokers, 439 (65%) had an identified driver mutation with 258 (38%) actionable (P < .0001). When comprehensively sequenced, 95% (70/74) of never-smokers had a driver mutation with 78% (58/74) actionable; whereas, for smokers, 75% (135/180) had a driver with only 47% (74/180) actionable (P < .0001). Within mutations groups, EGFR G719X and KRAS G12Cs were more common to smokers. For stage IV patients harboring EGFR-mutant tumors treated with EGFR-directed therapies, never-smokers had significantly improved OS compared to smokers (hazard ratio = 2.71; P = .025). In multivariable analysis, Asian ancestry and female sex remained significant predictors of (1) OS in stage IV patients and (2) likelihood of harboring a receptor of fusion-based driver. Conclusion Comprehensive NGS revealed driver alterations in 95% of never-smokers, with the majority having an associated therapy available. All efforts should be exhausted to identify or rule out the presence of an actionable driver mutation in all metastatic lung ADC.

Background: Upfront docetaxel or novel hormonal agents (NHA) such as abiraterone and enzalutamide have become the standard of care for metastatic hormone sensitive prostate cancer (mHSPC). However, data comparing the efficacy of docetaxel and NHAs in this setting are limited.Patients and Methods: This was a retrospective cohort study of patients with de novo mHSPC treated with upfront docetaxel or an NHA between January 1, 2014 and April 30, 2019 within the Mount Sinai Health System. Clinical data were extracted from the medical record. The primary outcome was failure-free survival (FFS), defined as the time to next treatment. The primary predictor was treatment with docetaxel or NHA. FFS was compared between the two groups using the Kaplan Meier method and multivariable Cox proportional hazards models. We additionally assessed the prognostic value of post-treatment PSA.Results: We identified 94 de novo mHSPC patients; 52 and 42 treated with upfront docetaxel and NHAs, respectively. NHAs were associated with significantly longer FFS compared to docetaxel (20.7 vs. 10.1 months, p=0.023). In a multivariable model adjusting for demographics and clinical factors, docetaxel was independently associated with worse FFS compared to NHAs (HR 1.96, 95% CI 1.12−3.45, p=0.019). High metastasis burden patients had a significantly longer FFS with NHAs than docetaxel (25.12 vs. 9.63 months, p=0.014), while there was no significant difference in FFS among low metastasis burden patients (NHA 20.71 vs. Docetaxel 26.5 months, p=0.9). Regardless of treatment, lower post-treatment PSA levels were associated with improved FFS (58.95 vs. 11.57 vs. 9.4 months for PSA ≤0.2, 0.2-0.4, >0.4ng/ml, respectively; pConclusion: Comparative analysis of real-world data demonstrated longer FFS in de novo mHSPC treated with NHA compared to docetaxel. In addition, the depth of PSA response following combination treatment may hold prognostic value for mHSPC outcomes.

6584 Background: Analysis of real-world data is critical for clear understanding of treatment effectiveness. Here, we explore the clinical utility of next-generation sequencing (NGS) and the impact of mutational landscapes on targeted therapy and outcomes in almost 10,000 patients in real-world setting. Methods: We constructed a data analysis platform that integrated NGS results with machine and manually curated electronic medical records data from a single large healthcare system. We assessed eligibility for a targeted therapy based on the constellation of mutations detected by NGS, investigated whether a matched therapy was given and how this affected patient outcome. Results: The study comprised of 9848 patients with NGS results across 90 cancer types including lung (2208;22%), colorectal (1495;15%), multiple myeloma (1153;12%), breast (783;8%), and prostate (480;5%) and other remaining cancers (3,729; 38%) from 2011 to 2021. Overall, 95% of patients had a positive NGS result, of whom 6364 (65%) had a targetable mutation in 34 genes per any NCCN guidelines in any cancer type. Of these, 2930 (46%) were late-stage (3-4). 820 patients across 31 cancer types received any of 54 targeted therapies based on an NGS result; 605/820 (74%) were stage 3-4; overall 605/2930 (21%) of all tested stage 3-4 patients received targeted therapy. Overall stage 4 patients with a targetable mutation who were treated with a targeted therapy had better 5-year overall survival (OS) than patients who did not (HR = 0.71, 95% CI 0.57-0.89, p = 0.003). We further analyzed important biomarkers in specific cancers. Stage 4 lung cancer patients carrying EGFR, ALK, ROS1 or MET alteration and receiving targeted therapy had better 5-year OS (HR 0.56, 95% CI 0.40-0.80, p = 0.001). We observed that multiple myeloma patients carrying KRAS and NRAS mutation received off-label Trametinib, however it did not improve their OS (HR 1.28, 95% CI 0.76-2.15, p = 0.4). Moreover, there are 665 patients with tumor mutational burden (TMB) across 64 cancer types. TMB has been categorized into high (55, 8%), intermediate (177, 27%) and low (433, 65%). OS was significantly longer in TMB-low patients compared to TMB-high and TMB-intermediate patients across all cancers (HR 0.63, 95% CI 0.43-0.92, p = 0.016). There are 5051 patients with microsatellite instability status across 72 cancers categorized into high (828, 16%), and low (4223, 84%) with no significant survival difference between groups. Conclusions: We show that real-world data offers important insights into clinical practice and patient outcome, with respect to genomic alterations and associated targeted therapies. Moreover, we have built an analytics platform which allows users to ask relevant clinical questions around outcome of patients treated with targeted therapy by genomics biomarker and potential to identify off-label use and clinical response in any cancer type.

e13545 Background: The ASCO Quality Oncology Practice Initiative (QOPI) was established in 2006 to facilitate quality measurement and continuous improvement of cancer care.1 ASCO and QOPI leadership encourage a continuous learning environment to develop new tools and methodologies that improve quality and maximize outcomes and value in oncology practice.2 Parallel advances in tumor molecular profiling, bioinformatics, and EMR data curation are adding new insights to support the real-world research of longitudinal patient journeys. Methods: Referencing the QOPI Certification Track 2021 Measures Summary, we employed data visualization techniques to create a precision oncology dashboard for breast cancer. This evaluation included 409 breast cancer patients for whom genomic testing was performed and presented at the Avera molecular tumor board. Patients were then matched to appropriate biomarker-based targeted therapies. Results: The dashboard identified and prioritized areas for enhanced data capture to inform strategies for care-coordination, research, and delivery of specialized care. Conclusions: An interactive, visual platform may help facilitate the integration of QOPI reporting into CancerLinQ, thereby fostering a real-time, bidirectional system for quality reporting, clinical decision support, and rapid learning.3,4 The next stage will (1) expand the tumor list; and (2) apply NLP methods to assess accuracy, outcomes and temporal reasoning to create interactive graphs for patient referral patterns and surgery decision drivers. References: 1. Neuss MN, Desch CE, McNiff KK, et al: A process for measuring the quality of cancer care: The Quality Oncology Practice Initiative. J Clin Oncol. 2005 2. Blayney DW, McNiff K, Eisenberg PD, Gilmore T, Jacobsen PB, Jacobson JO, Kadlubek PJ, Neuss MN, Simone J. Development and future of the American Society of Clinical Oncology's Quality Oncology Practice Initiative. J Clin Oncol. 2014 3. Blayney DW: Enhancing quality through innovation: American Society of Clinical Oncology presidential address 2010. J Clin Oncol. 2010 4. Schilsky R, Hauser R, Mann J, et al: Lessons learned from the development of the CancerLinQ prototype: Clinical decision support. J Clin Oncol. 31, 2013[Table: see text]

e15036 Background: Advances in tumor molecular profiling and bioinformatics are adding new insights to support real-world research. In this study, paired tumor NGS testing data was curated and analyzed from electronic medical records (EMR) to understand mutational and targeted therapy landscape. Methods: A database initiated in 2013 to collect data, including outcomes, on all patients referred to the molecular tumor board at the Avera Cancer Institute was curated and analyzed. A data pipeline that combined results from curated NGS data with curated EMR data from Avera was used to correlate targetable mutations to a corresponding therapy and assessed treatment patterns. Results: Data were from 1804 patients with 44 cancer types including breast (462; 26%), lung (338;19%), colorectal (198;11%), ovarian (168;9%), and uterine (100;5%). Overall, 83% of patients had a positive NGS result and 67% had a targetable mutation per NCCN guidelines. 32% of patients with a targetable mutation received targeted therapy per guideline. Overall, 381 patients with 28 tumor types received targeted therapies based on NGS results and targetable biomarkers. Of these, 288/381 (76%) were stage III-IV and 93/381 (24%) early stage/stage unknown. In non-small cell lung cancer, 76% of stage III-IV patients with mutations in EGFR (exon 19 deletion, L858, L861, S768, G719), MET (exon 14 skipping, amplification), BRAF V600 and ALK/ ROS1/ RET fusions received a targeted therapy per NCCN guidelines. In advanced breast cancer, 97% with ERBB2 amplification received targeted therapy (trastuzumab, pertuzumab, neratinib, lapatinib, tucatinib). 8% of advanced breast cancer patients with PIK3CA mutation received alpelisib, with all patients receiving the drug since 2019. 38% advanced breast cancer patients with BRCA1/2 mutation received Olaparib. In ovarian cancer, 48% of advanced stage patients received targeted therapy for BRCA 1/2, ATM, CDK12, CHEK2, ERBB2, FANCL, KRAS, ALK, BRAF alterations. Olaparib was used in 70% of advanced prostate cancer patients with BRCA1/2 mutations. Dabrafenib combined with Trametinib were most preferred for BRAF V600 mutation in melanoma and colorectal tumors respectively. Off label use of targeted therapy was observed in about 6% of advanced patients; examples include trametinib for KRAS/NRAS mutation [non-small cell lung cancer, colorectal, pancreatic, ovarian], PARP inhibitors for BRCA1/2, ATM mutations [urothelial, peritoneal], anti-ERBB2 inhibitors for ERBB2 in-frame, missense, exon 20 insertion mutations [lung and breast]. Conclusions: These study results demonstrate that automated data mining can provide insights into the genomic and therapeutic landscape of a real-world patient population. Across all tumor types, most patients are being given appropriate targeted therapies as per guidelines. Off-label use of targeted therapy was also observed.

Background: Historically, high rates of actionable driver mutations have been reported in never-smokers with lung adenocarcinoma (LUAD); however, in the era of modern, comprehensive cancer mutation sequencing, this relationship necessitates a more detailed analysis. Methods: All Mount Sinai patients between 01/01/2015 and 6/01/2020 with a diagnosis of LUAD of any stage with known smoking status who received genomic testing were included. Most patients were analyzed using the Sema4 hotspot panel or the OCAv3 NGS panel conducted at Sema4. Patients were considered fully genotyped if they were comprehensively analyzed for alterations in EGFR, KRAS, MET, ALK, RET, ROS1, BRAF, NTRK1-3, and ERBB2, otherwise they were considered partially genotyped.Findings236 never-smokers and 671 smokers met the above criteria. Of the never-smokers, 201 (85%) had a driver mutation with 175 (74%) considered actionable. Among smokers, 436 (65%) had an identified driver mutation with 268 (40%) actionable (p

112 Background: Next-generation sequencing (NGS) is increasingly common in clinical practice, but its clinical utility may depend on the availability of sequencing-directed therapies (SDT). There were no FDA-approved SDTs in prostate cancer (PCa) until 2020, when PARP inhibitors olaparib and rucaparib were approved for tumors bearing alterations in certain homologous recombination repair (HRR) genes. We assessed the clinical utility of NGS in PCa before and after the approval of these agents in a single academic medical center. Methods: This was a retrospective single-center study including all PCa patients seen at Mount Sinai Hospital (New York, NY) between 2018–2021 who received NGS via the 161-gene Sema4 Signal Solid Tumor Panel. Clinical data were extracted from the Mount Sinai electronic medical record using a proprietary automated pipeline with limited manual curation (Sema4 PRODB). The primary outcome was clinical utility in metastatic PCa, defined as the proportion of metastatic PCa patients who received SDT. Secondary outcomes included time-to-next-treatment (TTNT, defined as time from SDT start to the start of next systemic therapy) and the proportion of patients with clinically actionable (as of 9/2021) alterations, defined as either Tier 1 (associated with FDA-approved treatments in prostate cancer) or Tier 2 (associated with either off-label or investigational agents). Results: The cohort consisted of 332 PCa patients; 51% (N = 170) were sequenced in 2020 or later. The median age at diagnosis was 65 (IQR 12). The most advanced stage documented was localized for 39% (N = 129) and metastatic for 61% (N = 203). Overall, 167 actionable alterations were identified in 125 patients (38% of cohort). Of the actionable alterations, 31% (N = 51) were Tier 1 and 69% (N = 116) were Tier 2. Of the 44 patients with Tier 1 alterations, 8 (18%) received SDT (all received olaparib). The proportion of metastatic patients receiving olaparib increased from 1% (2/145) before 2020 to 10% (6/58) during or after 2020 (p = 0.008). Of the 36 patients not receiving olaparib: 20 were sequenced before FDA approval and were treated with an alternative systemic therapy; 8 had localized disease and were not eligible; 8 had limited follow-up or unknown treatment status. For those who received olaparib, median TTNT was 5 months. Conclusions: In this single-center retrospective cohort, clinical utility of NGS was linked to treatment landscape. Increases in NGS test volume and olaparib use coincided with the approval of PARP inhibitors for patients with HRR-mutated prostate cancers. Notably, NGS was used to match patients to off-label/ investigational olaparib before its FDA approval.[Table: see text]

Glycogen debranching enzyme (AGL) and Glycogen phosphorylase (PYG) are responsible for glycogen breakdown. We have earlier shown that AGL is a regulator of bladder tumor growth. Here we investigate the role of AGL in non-small cell lung cancers (NSCLC). Short hairpin RNA (shRNA) driven knockdown of AGL resulted in increased anchorage independent and xenograft growth of NSCLC cells. We further establish that an increase in hyaluronic acid (HA) synthesis driven by Hyaluronic Acid Synthase 2 (HAS2) is critical for anchorage independent growth of NSCLC cells with AGL loss. Using gene knockdown approach against HAS2 and by using 4-methylumbelliferone (4MU), an inhibitor of HA synthesis, we show that HA synthesis is critical for growth of NSCLC cells that have lost AGL. We further show NSCLC cells without AGL expression are dependent on RHAMM for HA signaling and growth. Analysis of NSCLC patient datasets established that patients with low AGL/high HAS2 or low AGL/high RHAMM mRNA expression have poor overall survival compared to patients with high AGL/low HAS2 or high AGL/low RHAMM expression. We show for the first time that loss of AGL promotes anchorage independent growth of NSCLC cells. We further show that HAS2 driven HA synthesis and signaling via RHAMM is critical in regulating growth of these cancer cells with AGL loss. Further patients presenting with low AGL and HAS2 or RHAMM over expressing tumors might present the ideal cohort who would respond to inhibitors of HA synthesis and signaling.

e17047 Background: The addition of docetaxel or a novel hormonal agent (NHA), such as abiraterone acetate or enzalutamide, has become standard of care for mHSPC, but prospective data for comparative efficacy remains limited. Clinical variables abstracted through natural language processing of free text from patient charts can provide real-world data to answer important clinical questions. Methods: Using an innovative data abstraction process, we retrospectively identified men with de novo mHSPC within deidentified charts from the Mount Sinai Health System treated with either docetaxel or a NHA between January 1, 2014 and April 30, 2019. Dates were chosen to reflect the timeline for which these therapeutic agents received regulatory approval for mHSPC, but also to allow sufficient clinical follow up after treatment initiation. Primary outcome of failure-free survival (FFS), defined as the time to next treatment, was assessed using the Kaplan-Meier method and multivariable Cox proportional hazards models. We additionally performed multivariable analysis to evaluate the prognostic significance of post-treatment PSA nadir on FFS. Results: A total of 94 de novo mHSPC patients that received either docetaxel or an NHA were identified using proprietary Sema4 data abstraction process: 52 received docetaxel, 42 received an NHA. Use of an upfront NHA in mHSPC was associated with a significantly longer FFS compared to docetaxel (20.7 vs. 10.1 months, p = 0.023). While NHAs were associated with a significantly longer FFS than docetaxel in patients with high metastatic burden of disease (25.12 vs. 9.63 months, p = 0.014), this was not observed in low-volume disease (20.71 vs. 26.5 months, p = 0.9). In multivariable model analysis adjusting for age, baseline PSA, and metastasis burden, docetaxel remains independently associated with worse FFS compared to NHA (HR 1.96, 95% CI 1.12−3.45, p = 0.019). Irrespective of docetaxel or NHA use, lower post-treatment PSA nadir levels were associated with improved FFS (58.95 vs. 11.57 vs. 9.4 months for PSA ≤0.2, 0.2-0.4, > 0.4ng/ml, respectively; p < 0.001). Conclusions: Clinical variables abstracted from deidentified clinical documentation can efficiently provide relevant and reliable data upon which clinical research can be based. Comparative analysis of real-world data demonstrates superior FFS in de novo mHSPC treated with a NHA as compared to docetaxel. The depth of PSA response holds prognostic value for mHSPC outcomes, regardless of treatment used.

Background We present a rare case where distant metastasis of a low grade bladder tumor was observed. We carried out detailed genomic analysis and cell based experiments on patient tumor samples to study tumor evolution, possible cause of disease and provide personalized treatment strategies. Case presentation A man with a smoking history was diagnosed with a low-grade urothelial carcinoma of the bladder and a concurrent high-grade upper urinary tract tumor. Seven years later he had a lung metastasis. We carried out exome sequencing on all the patient’s tumors and peripheral blood (germline) to identify somatic variants. We constructed a phylogenetic tree to capture how the tumors are related and to identify somatic changes important for metastasis. Although distant metastasis of low-grade bladder tumor is rare, the somatic variants in the tumors and the phylogenetic tree showed that the metastasized tumor had a mutational profile most similar to the low grade urothelial carcinoma. The primary and the metastatic tumors shared several important mutations, including in the KMT2D and the RXRA genes. The metastatic tumor also had an activating MTOR mutation, which may be important for tumor metastasis. We developed a mutational signature to understand the biologic processes responsible for tumor development. The mutational signature suggests that the tumor mutations are associated with tobacco carcinogen exposure, which is concordant with the patient’s smoking history. We cultured cells from the lung metastasis to examine proliferation and signaling mechanisms in response to treatment. The mTOR inhibitor Everolimus inhibited downstream mTOR signaling and induced cytotoxicity in the metastatic tumor cells. Conclusion We used genomic analysis to examine a rare case of low grade bladder tumor metastasis to distant organ (lung). Our analysis also revealed exposure to carcinogens found is tobacco as a possible cause in tumor development. We further validated that the patient might benefit from mTOR inhibition as a potential salvage therapy in an adjuvant or recurrent disease setting. Electronic supplementary material The online version of this article (10.1186/s12894-018-0386-8) contains supplementary material, which is available to authorized users.

Metabolism has been a heavily investigated topic in cancer research for the past decade. Although the role of aerobic glycolysis (the Warburg effect) in cancer has been extensively studied, abnormalities in other metabolic pathways are only just being understood in cancer. One such pathway is glycogen metabolism; its involvement in cancer development, particularly in urothelial malignancies, and possible ways of exploiting aberrations in this process for treatment are currently being studied. New research shows that the glycogen debranching enzyme amylo-α-1,6-glucosidase, 4-α-glucanotransferase (AGL) is a novel tumour suppressor in bladder cancer. Loss of AGL leads to rapid proliferation of bladder cancer cells. Another enzyme involved in glycogen debranching, glycogen phosphorylase, has been shown to be a tumour promoter in cancer, including in prostate cancer. Studies demonstrate that bladder cancer cells in which AGL expression is lost are more metabolically active than cells with intact AGL expression, and these cells are more sensitive to inhibition of both glycolysis and glycine synthesis--two targetable pathways. As a tumour promoter and enzyme, glycogen phosphorylase can be directly targeted, and preclinical inhibitor studies are promising. However, few of these glycogen phosphorylase inhibitors have been tested for cancer treatment in the clinical setting. Several possible limitations to the targeting of AGL and glycogen phosphorylase might also exist.

Activating RAS mutations are common in human tumors. These mutations are often markers for resistance to therapy and subsequent poor prognosis. So far, targeting the RAF-MEK-ERK and PI3K-AKT signaling pathways downstream of RAS is the only promising approach in the treatment of cancer patients harboring RAS mutations. RAL GTPase, another downstream effector of RAS, is also considered as a therapeutic option for the treatment of RAS-mutant cancers. The RAL GTPase family comprises RALA and RALB, which can have either divergent or similar functions in different tumor models. Recent studies on non-small cell lung cancer (NSCLC) have showed that different RAS mutations selectively activate specific effector pathways. This observation requires broader validation in other tumor tissue types, but if true, will provide a new approach to the treatment of RAS-mutant cancer patients by targeting specific downstream RAS effectors according to the type of RAS mutation. It also suggests that RAL GTPase inhibition will be an important treatment strategy for tumors harboring RAS glycine to cysteine (G12C) or glycien to valine (G12V) mutations, which are commonly found in NSCLC and pancreatic cancer.

Introduction: KRAS mutations are poor prognostic markers for patients with non–small-cell lung cancer (NSCLC). RALA and RALB GTPases lie downstream of RAS and are implicated in RAS-mediated tumorigenesis. However, their biological or prognostic role in the context of KRAS mutation in NSCLC is unclear. Methods: Using expression analysis of human tumors and a panel of cell lines coupled with functional in vivo and in vitro experiments, we evaluated the prognostic and functional importance of RAL in NSCLC and their relationship to KRAS expression and mutation. Results: Immunohistochemical (N = 189) and transcriptomic (N = 337) analyses of NSCLC patients revealed high RALA and RALB expression was associated with poor survival. In a panel of 14 human NSCLC cell lines, RALA and RALB had higher expression in KRAS mutant cell lines whereas RALA but not RALB activity was higher in KRAS mutant cell lines. Depletion of RAL paralogs identified cell lines that are dependent on RAL expression for proliferation and anchorage independent growth. Overall, growth of NSCLC cell lines that carry a glycine to cystine KRAS mutation were more sensitive to RAL depletion than those with wild-type KRAS. The use of gene expression and outcome data from 337 human tumors in RAL-KRAS interaction analysis revealed that KRAS and RAL paralog expression jointly impact patient prognosis. Conclusion: RAL GTPase expression carries important additional prognostic information to KRAS status in NSCLC patients. Simultaneously targeting RAL may provide a novel therapeutic approach in NSCLC patients harboring glycine to cystine KRAS mutations.

Background Loss of Amylo-alpha-1-6-glucosidase-4-alpha-glucanotransferase (AGL) drives rapid proliferation of bladder cancer cells by upregulating Hyaluronic acid(HA) Synthase (HAS2) mediated HA synthesis. However the role of HA receptors CD44 and Hyaluronan Mediated Motility Receptor (RHAMM) in regulating the growth of bladder cancer cells driven by loss of AGL has not been studied. Methods Western blot analysis and Terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) assay was carried out to study cellular apoptosis with HAS2, CD44 and RHAMM loss in bladder cancer cells with and without AGL expression. Proliferation and softagar assays were carried out to study cellular anchorage dependent and independent growth. Clinicopathologic analysis was carried out on bladder cancer patient datasets. Results Higher amounts of cleaved Cas3, Cas9 and PARP was observed in AGL low bladder cancer cell with loss of HAS2, CD44 or RHAMM. TUNEL staining showed more apoptotic cells with loss of HAS2, CD44 or RHAMM in AGL low bladder cancer cells. This revealed that bladder cancer cells whose aggressive growth is mediated by loss of AGL are susceptible to apoptosis with loss of HAS2, CD44 or RHAMM. Interestingly loss of either CD44 or RHAMM induces apoptosis in different low AGL expressing bladder cancer cell lines. Growth assays showed that loss of CD44 and RHAMM predominantly inhibit anchorage dependent and independent growth of AGL low bladder cancer cells. Clinicopathologic analysis revealed that high RHAMM mRNA expression is a marker of poor patient outcome in bladder cancer and patients with high RHAMM and low AGL tumor mRNA expression have poor survival. Conclusion Our findings strongly point to the importance of the HAS2-HA-CD44/RHAMM pathway for rapid growth of bladder cancer cells with loss of AGL and provides rational for targeting this pathway at various steps for “personalized” treatment of bladder cancer patients based of their AGL expression status. Electronic supplementary material The online version of this article (doi:10.1186/s12885-016-2756-5) contains supplementary material, which is available to authorized users.

Products of proto-oncogenes c-MET and RON belong to a subfamily of receptor tyrosine kinases that contribute significantly to tumorigenic progression. In primary tumors, altered c-MET/RON expression transduces signals regulating invasive growth that is characterized by cell migration and matrix invasion. These pathogenic features provide the basis for targeting c-MET/RON in cancer therapy. In the last decade, various approaches have been investigated to suppress c-MET/RON-transduced oncogenesis. Among the therapeutics developed, monoclonal antibodies (mAbs) and small-molecule inhibitors (SMIs) have emerged as promising candidates. The mechanism of these therapeutic candidates is the disruption of tumor dependency on c-MET/RON signals for survival. The mAbs specific to hepatocyte growth factor (AMG102) and c-MET (MetMAb) are both humanized and able to block c-MET signaling, leading to inhibition of tumor cell proliferation in vitro and inhibition of tumor growth in xenograft models. The mAb AMG102 neutralizes hepatocyte growth factor and enhances the cytotoxicity of various chemotherapeutics to tumors in vivo. AMG102 is currently in phase II clinical trials for patients with advanced solid tumors. IMC-41A40 and Zt/f2 are RON-specific mAbs that down-regulate RON expression and inhibit ligand-induced phosphorylation. Both mAbs inhibit tumor growth in mice mediated by colon and pancreatic cancer cells. SMIs specific to c-MET (ARQ107 and PF-02341066) are in various phases of clinical trials. Therapeutic efficacy has also been observed with dual inhibitors such as Compound I, which is specific to c-MET/RON. However, a potential issue is the emergence of acquired resistance to these inhibitors. Clearly, development of c-MET/RON therapeutics provides opportunities and challenges for combating cancer in the future.

Loss of glycogen debranching enzyme (AGL) has been shown to promote growth of bladder and non-small cell lung cancer. AGL loss predominantly assists anchorage independent growth of non-small cell lung cancer (NSCLC) cells. However the mechanism driving this anchorage independent growth with AGL loss is not well understood. To identify the driver pathways which contributions to increased anchorage independent growth with AGL loss, we carried out a phospho-kinase screen in A549 NSCLC cells with and without AGL expression. The kinase screen identified an increase in phospho-FAK (Tyr 576/577) levels with loss of AGL. The result of the screen was validated using separate independent Western blot experiments in A549 and other NSCLC cell lines which showed an increase in FAK activation at Tyr 576/577 with loss of AGL. We next treated NSCLC cells with and without AGL with FAK specific inhibitor (FAK inhibitor 14). Treatment with FAK inhibitor 14 had a greater cytotoxic effect (p Citation Format: Sunny Guin, Craig Richmond. AGL loss promotes anchorage independent growth of non-small cell lung cancer by activating FAK [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3449.

Overexpression of the RON receptor tyrosine kinase exists in various cancers and contributes to malignant progression. To validate RON as a targeting moiety for delivery of chemoagents for enhanced tumor cytotoxicity, immunoliposomes (IL) loaded with doxorubicin (Dox) were formulated followed by postinsertion of monoclonal antibodies Zt/g4, Zt/c1, or their Fab fragments specific to the RON extracellular domains. Flow cytometry analysis showed that Zt/g4 or Zt/c1-IL binds to cancer cells and causes RON internalization as evident in confocal analysis of intracellular fluorescence intensity. The antibody-directed IL uptake by cancer cells is in both dose and time-dependent manners. Studies of cytotoxicity of individual IL in vitro against colon or breast cancer cell lines revealed that Zt/g4 directed Dox-IL displayed increased cytotoxic activities with a significant reduction of IC(50) values. An average of 8-fold increases in cytotoxic efficiency was achieved among four cell lines tested. Moreover, Zt/g4 directed Dox-IL also displayed the effective killing of cancer cells that are insensitive to pegylated liposomal doxorubicin. The effect of Zt/c1-Dox-IL was not as strong as Zt/g4-Dox-IL, and only moderate activities were observed. IL coupled with the Fab fragments of Zt/g4 or Zt/c1 show moderate activities against cancer cells. The ineffectiveness seemed to be related to the weak activities of the Fab fragments in the induction of RON internalization, which resulted in reduced drug uptakes. We conclude that anti-RON antibody-directed drug delivery is effective for increased uptake of cytotoxic drugs. Antibody-based RON targeting could be developed into a potential therapeutic for treatment of malignant cancers.

Purpose: We demonstrated that amylo-alpha-1-6-glucosidase-4-alpha-glucanotransferase (AGL) is a tumor growth suppressor and prognostic marker in human bladder cancer. Here we determine how AGL loss enhances tumor growth, hoping to find therapeutically tractable targets/pathways that could be used in patients with low AGL–expressing tumors. Experimental Design: We transcriptionally profiled bladder cell lines with different AGL expression. By focusing on transcripts overexpressed as a function of low AGL and associated with adverse clinicopathologic variables in human bladder tumors, we sought to increase the chances of discovering novel therapeutic opportunities. Results: One such transcript was hyaluronic acid synthase 2 (HAS2), an enzyme responsible for hyaluronic acid (HA) synthesis. HAS2 expression was inversely proportional to that of AGL in bladder cancer cells and immortalized and normal urothelium. HAS2-driven HA synthesis was enhanced in bladder cancer cells with low AGL, and this drove anchorage-dependent and independent growth. siRNA-mediated depletion of HAS2 or inhibition of HA synthesis by 4-methylumbelliferone (4MU) abrogated in vitro and xenograft growth of bladder cancer cells with low AGL. AGL and HAS2 mRNA expression in human tumors was inversely correlated in patient datasets. Patients with high HAS2 and low AGL tumor mRNA expression had poor survival, lending clinical support to xenograft findings that HAS2 drives growth of tumors with low AGL. Conclusions: Our study establishes HAS2-mediated HA synthesis as a driver of growth of bladder cancer with low AGL and provides preclinical rationale for personalized targeting of HAS2/HA signaling in patients with low AGL–expressing tumors. Clin Cancer Res; 22(5); 1274–83. ©2015 AACR.

Glycogen Debranching Enzyme (AGL) is involved in glycogen breakdown. Compromise in glycogen breakdown due to loss of function mutations in the AGL gene lead to metabolic disease - Glycogen Storage Disease Type III. We have previously shown that loss of AGL results in rapid growth of bladder cancer cells using extensive in vitro and in vivo experiments. Here we test whether AGL regulate growth of non-small cell lung cancer (NSCLC) cells. We show that loss of AGL promotes rapid growth of NSCLC cells using anchorage independent growth assay. Loss of AGL also resulted in rapid xenograft growth of NSCLC cells when injected subcutaneously in immunocompromised mice. Whereas overexpression of AGL reduce the growth of these NSCLC cells. Further loss of glycogen phosphorylase the other enzyme involved in glycogen breakdown does not promote aggressive growth of these cancer cells. This observation is similar to our findings in bladder cancer which confirms that AGL regulates tumor growth independent of its role in glycogen metabolism. Thus using in vitro and in vivo experiments we show that AGL can regulate the growth of multiple tumor types such as bladder cancer and NSCLC. The exact mechanism on how AGL regulates NSCLC growth needs further investigation. Citation Format: David R. Meier, Benjamin Weinhaus, Darby Oldenburg, Sunny Guin. Loss of glycogen debranching enzyme (AGL) promotes rapid growth of non-small cell lung cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1545. doi:10.1158/1538-7445.AM2017-1545

Bladder cancer is the most common malignancy of the urinary system, yet our molecular understanding of this disease is incomplete, hampering therapeutic advances.Here we used a genome-wide functional short-hairpin RNA (shRNA) screen to identify suppressors of in vivo bladder tumor xenograft growth (n = 50) using bladder cancer UMUC3 cells. Next-generation sequencing was used to identify the most frequently occurring shRNAs in tumors. Genes so identified were studied in 561 patients with bladder cancer for their association with stratification of clinical outcome by Kaplan-Meier analysis. The best prognostic marker was studied to determine its mechanism in tumor suppression using anchorage-dependent and -independent growth, xenograft (n = 20), and metabolomic assays. Statistical significance was determined using two-sided Student t test and repeated-measures statistical analysis.We identified the glycogen debranching enzyme AGL as a prognostic indicator of patient survival (P = .04) and as a novel regulator of bladder cancer anchorage-dependent (P.001), anchorage-independent (mean ± standard deviation, 180 ± 23.1 colonies vs 20±9.5 in control, P.001), and xenograft growth (P.001). Rescue experiments using catalytically dead AGL variants revealed that this effect is independent of AGL enzymatic functions. We demonstrated that reduced AGL enhances tumor growth by increasing glycine synthesis through increased expression of serine hydroxymethyltransferase 2.Using an in vivo RNA interference screen, we discovered that AGL, a glycogen debranching enzyme, has a biologically and statistically significant role in suppressing human cancer growth.

The Ras-like GTPases RalA and RalB are important drivers of tumour growth and metastasis. Chemicals that block Ral function would be valuable as research tools and for cancer therapeutics. Here we used protein structure analysis and virtual screening to identify drug-like molecules that bind to a site on the GDP-bound form of Ral. The compounds RBC6, RBC8 and RBC10 inhibited the binding of Ral to its effector RALBP1, as well as inhibiting Ral-mediated cell spreading of murine embryonic fibroblasts and anchorage-independent growth of human cancer cell lines. The binding of the RBC8 derivative BQU57 to RalB was confirmed by isothermal titration calorimetry, surface plasmon resonance and (1)H-(15)N transverse relaxation-optimized spectroscopy (TROSY) NMR spectroscopy. RBC8 and BQU57 show selectivity for Ral relative to the GTPases Ras and RhoA and inhibit tumour xenograft growth to a similar extent to the depletion of Ral using RNA interference. Our results show the utility of structure-based discovery for the development of therapeutics for Ral-dependent cancers.

Cancer stem cells (CSCs) contribute to pancreatic cancer tumorigenesis through tumor initiation, drug resistance, and metastasis. Currently, therapeutics targeting pancreatic CSCs are under intensive investigation. This study tested a novel strategy that utilizes the RON receptor as a drug delivery moiety for increased therapeutic activity against pancreatic CSCs. CD24(+)CD44(+)ESA(+) triple-positive pancreatic CSCs (CSCs(+24/44/ESA)) were obtained from spheroids of pancreatic L3.6pl cancer cells by sequential magnetic cell sorting methods. These cells displayed a spherical growth pattern, expressed the unique self-renewal marker Bmi-1, redifferentiated into an epithelial phenotype, acquired an epithelial to mesenchymal phenotype, and caused tumor formation in animal models. Among several receptor tyrosine kinases examined, RON was highly expressed and sustained by CSCs(+24/44/ESA). This feature provided the cellular basis for validating the therapeutic effectiveness of anti-RON antibody Zt/c9-directing doxorubicin-immunoliposomes (Zt/c9-Dox-IL). Zt/c9-Dox-IL specifically interacted with CSCs(+24/44/ESA) and rapidly caused RON internalization, which led to the uptake of liposome-coated Dox. Moreover, Zt/c9-Dox-IL was effective in reducing viability of L3.6pl cells and CSCs(+24/44/ESA). The IC(50) values between free Dox (62.0 ± 3.1 μM) and Zt/c9-Dox-IL (95.0 ± 6.1 μM) treated CSCs(+24/44/ESA) were at relatively comparable levels. In addition, Zt/c9-Dox-IL in combination with small molecule inhibitors lapatinib, sunitinib, or dasatinib further reduced the viability of CSCs(+24/44/ESA). In conclusion, RON expression by CSCs(+24/44/ESA) is a suitable molecule for the targeted delivery of chemoagents. The anti-RON antibody-directed delivery of chemotherapeutics is effective in reducing viability of pancreatic CSCs.

Overexpression of the RON receptor tyrosine kinase contributes to pathogenesis of epithelial cancers and disruption of RON signals has potential for therapeutic intervention. Here, we report the inhibitory effects of monoclonal antibodies (Zt/g4, Zt/f2 and Zt/c9) on RON expression and tumorigenic activities in colon cancer cells. Persistent treatment of colon SW620 or other cells with Zt/g4 dramatically down-regulated RON expression as evident by Western blot and cell surface fluorescent analyses. The effect was both concentration and time-dependent and specific to RON but not to structure-related MET or -unrelated EGFR. The cause of reduction was antibody-induced receptor internalization followed by protein degradation through lysosome and proteasome-mediated pathways. Down-regulation of RON impaired intracellular signaling events. Phosphorylation of Erk1/2 and AKT was dramatically reduced after Zt/g4 treatment. Zt/g4 treatment also affects activities of DVL and GSK-3beta, which results in diminished beta-catenin nuclear translocation. Functional studies revealed that Zt/g4 treatment changes cellular morphology and affects colony formation in soft agar. It also increased the sensitivity of SW620 cells in response to gemcitabine-induced cytotoxicity. In this case, the death of SW620 cells was significantly increased when Zt/g4 was used in combination with gemcitabine. We conclude that persistent treatment of cancer cells with antibodies specific to RON extracellular domains results in down-regulation of RON expression. The reduced RON expression is accompanied with impaired signaling events, diminished tumorigenic activities and enhanced sensitivity towards cytotoxic drugs. Thus, Zt/g4-directed targeting could have therapeutic implication for controlling tumorigenic phenotypes of cancer cells.

Hypoxia contributes to acquired drug resistance in various cancer cells. The underlying mechanism is cellular insensitivity regulated by hypoxia-inducible factors (HIF), which impairs drug uptake, transport, and metabolism. The current study determines anti-RON antibody-directed cytotoxicity of doxorubicin (Dox)-immunoliposomes (IL) in hypoxic colon cancer cells.Cells were cultured under hypoxia (1% O(2), 5% CO(2), and 96% N(2)) for 24 h. Dox-loaded IL were formulated followed by post-insertion of monoclonal antibody Zt/g4 specific to RON. Western blotting was used to detect HIF-1α and RON expression. Cellular uptake of Zt/g4-conjugated IL was determined by confocal and internalization assays. Cell viability was assessed by the MTT assay.RON and HIF-1α expression were observed in hypoxic colon HCT116 and SW620 cells. Resistance to Dox-induced cytotoxicity was acquired in hypoxic cells with increased IC(50) values. However, acquired resistance was attenuated by Zt/g4-directed Dox-IL, which displays increased cytotoxic activities. IL binding and uptake revealed that hypoxic RON expression is functional, which mediates high levels of Zt/g4-Dox-IL binding and cytoplasmic internalization. Zt/g4-Dox-IL is effective in killing hypoxic HCT116 and SW620 cells with reduced IC(50) values compared to Dox and pegylated-liposomal Dox. These effects were dependent on hypoxic RON expression. HCC1937 cells with diminished RON expression under hypoxia were insensitive to Zt/g4-Dox-IL-induced cytotoxic effect.RON expressed by hypoxic colon cancer cells is thus a potential targeting molecule for delivery of chemotherapeutics. The ability of anti-RON mAb to direct Dox-IL cytotoxicity could be developed for attenuating hypoxia-acquired drug resistance in various cancer cells.

In bladder cancer, reduced levels of Amylo-alpha-1-6-glucosidase-4-alpha-glucanotransferase (AGL), an enzyme involved in glycogenolysis and mutated in glycogen storage disease type III, enhances proliferation in vitro and tumor growth in vivo. To identify how reduced levels of AGL promote bladder cancer growth, we gene expression profiled two bladder cancer cell lines with and without siRNA mediated AGL depletion. This identified that hyaluronic acid synthase 2 (HAS2), an enzyme responsible for hyaluronic acid (HA) synthesis, is upregulated with AGL depletion. We validated this finding in several additional bladder cancer cell lines and also found that HA levels were 2-fold higher bladder cancer cells with low AGL compared to control. Interestingly, siRNA induced knockdown of HAS2 preferentially reduced monolayer, anchorage independent and xenograft growth in bladder cancer cells with low AGL. 4-Methylumbelliferone (4-MU), an inhibitor of HA synthesis, had similar effects. Analysis of human bladder cancer tissues showed that AGL and HAS2 mRNA expression are negatively correlated in 5/8 patient datasets (N = 725). Bladder cancer patients with high HAS2 and low AGL expression had worse survival than patients with the reciprocal relationship between these two genes suggesting that HAS2 is a driver of bladder tumor growth with AGL loss establish the HAS2/HA axis as a major driver and target of therapy in bladder tumors with low AGL. Citation Format: Sunny Guin, Yuanbin Ru, Carolyn R. Lew, Neeraj Agarwal, Charles Owens, Dan Theodorescu. HAS2 is a critical effector for AGL mediated regulation of tumor growth. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4949. doi:10.1158/1538-7445.AM2015-4949

The Ral GTPase family, consisting of the Ral A and B isoforms contributes to tumor formation, invasion and metastasis, however their role in non-small cell lung cancer (NSCLC) is yet to be validated. Recently, we investigated the role of Ral GTPases in NSCLC by in vitro expression, colony formation and migration assay, in vivo tumor formation experiments, and analysis of microarray data from NSCLC patients. In vitro, Ral A and Ral B was expressed in all NSCLC cell lines studied (14) to varying levels. Increased expression of Ral A or Ral B was more frequent in Ras mutant cell lines (Ral A elevated in 2/8 cell lines with mutant KRas vs. 0/6 cell lines with WT KRas, Ral B elevated in 5/8 cell lines with mutant KRas vs. 2/6 WT KRas). Soft agar experiments with transient knockdown of Ral A, Ral B and Ral A+B in these cell lines demonstrated significant decrease (p Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2138. doi:1538-7445.AM2012-2138

Background Overexpression of the RON receptor tyrosine kinase contributes to epithelial cell transformation, malignant progression, and acquired drug resistance. RON also has been considered as a potential target for therapeutic intervention. This study determines biochemical features and inhibitory activity of a mouse monoclonal antibody (mAb) Zt/f2 in experimental cancer therapy. Results Zt/f2 is a mouse IgG2a mAb that is highly specific and sensitive to human RON and its oncogenic variants such as RON160 (ED50 = 2.3 nmol/L). Receptor binding studies revealed that Zt/f2 interacts with an epitope(s) located in a 49 amino acid sequence coded by exon 11 in the RON β-chain extracellular sequences. This sequence is critical in regulating RON maturation and phosphorylation. Zt/f2 did not compete with ligand macrophage-stimulating protein for binding to RON; however, its engagement effectively induced RON internalization, which diminishes RON expression and impairs downstream signaling activation. These biochemical features provide the cellular basis for the use of Zt/f2 to inhibit tumor growth in animal model. Repeated administration of Zt/f2 as a single agent into Balb/c mice results in partial inhibition of tumor growth caused by transformed NIH-3T3 cells expressing oncogenic RON160. Colon cancer HT-29 cell-mediated tumor growth in athymic nude mice also was attenuated following Zt/f2 treatment. In both cases, ~50% inhibition of tumor growth as measured by tumor volume was achieved. Moreover, Zt/f2 in combination with 5-fluorouracil showed an enhanced inhibition effect of ~80% on HT-29 cell-mediated tumor growth in vivo. Conclusions Zt/f2 is a potential therapeutic mAb capable of inhibiting RON-mediated oncogenesis by colon cancer cells in animal models. The inhibitory effect of Zt/f2 in vivo in combination with chemoagent 5-fluorouracil could represent a novel strategy for future colon cancer therapy.

Background Epithelial to mesenchymal transition (EMT) occurs during cancer cell invasion and malignant metastasis. Features of EMT include spindle-like cell morphology, loss of epithelial cellular markers and gain of mesenchymal phenotype. Activation of the RON receptor tyrosine kinase by macrophage-stimulating protein (MSP) has been implicated in cellular EMT program; however, the major signaling determinant(s) responsible for MSP-induced EMT is unknown. Results The study presented here demonstrates that RSK2, a downstream signaling protein of the Ras-Erk1/2 pathway, is the principal molecule that links MSP-activated RON signaling to complete EMT. Using MDCK cells expressing RON as a model, a spindle-shape based screen was conducted, which identifies RSK2 among various intracellular proteins as a potential signaling molecule responsible for MSP-induced EMT. MSP stimulation dissociated RSK2 with Erk1/2 and promoted RSK2 nuclear translocation. MSP strongly induced RSK2 phosphorylation in a dose-dependent manner. These effects relied on RON and Erk1/2 phosphorylation, which is significantly potentiated by transforming growth factor (TGF)-β1, an EMT-inducing cytokine. Specific RSK inhibitor SL0101 completely prevented MSP-induced RSK phosphorylation, which results in inhibition of MSP-induced spindle-like morphology and suppression of cell migration associated with EMT. In HT-29 cancer cells that barely express RSK2, forced RSK2 expression results in EMT-like phenotype upon MSP stimulation. Moreover, specific siRNA-mediated silencing of RSK2 but not RSK1 in L3.6pl pancreatic cancer cells significantly inhibited MSP-induced EMT-like phenotype and cell migration. Conclusions MSP-induced RSK2 activation is a critical determinant linking RON signaling to cellular EMT program. Inhibition of RSK2 activity may provide a therapeutic opportunity for blocking RON-mediated cancer cell migration and subsequent invasion.

Hypoxia is a pathogenic factor observed in solid tumors, which plays a critical role in tumor malignancy and drug resistance. The MET and RON receptor tyrosine kinases belong to a unique proto-oncogene family and contribute to tumorigenic progression and malignant phenotypes in various epithelial cancers. To address their pathogenic significance under chronic hypoxic condition (1% O2, 5% CO2 for 5 days), functional analysis of MET and RON were conducted using colon cancer HCT116 and HT29 cells as models. Contrary to previous reports, we consistently observed that levels of MET and RON were significantly decreased over a period of 5 days under chronic hypoxic condition as documented by Western blot and cell-surface fluorescent analysis. The reduction was also accompanied with decreased in both spontaneous and ligand (HGF/MSP)-induced tyrosine phosphorylation manners, which affected the downstream signaling cascades. Moreover, we observed that hypoxia-induced HIF-1α expression (known as a positive regulator for both receptors) is unable to sustain MET or RON expression, suggesting that the receptor down-regulation is mediated through a HIF-1α-independent mechanism. RT-PCR analysis revealed that diminished MET and RON expression occurs at the mRNA transcription level. However, increase in protein degradation also contributed to the observed reduction. Functional studies further demonstrated that chronic hypoxia facilitates colon cancer cells to develop a unique pathogenic phenotype. This phenotype was featured by reduced cell migration, decreased cell proliferation, and lack of S phase in cell cycle profile. Tumor cells were also insensitive in response towards HGF or MSP-induced cell movement and replication. These cancer cells were resistant to cytotoxic effects induced by MET-RON duel small molecule inhibitors such as PHA665752 and compound I. As shown by cytotoxicity assay, the IC50 values of these inhibitors in cell survival were significantly increased in cancer cells under chronic hypoxic treatment compared to normoxic cells. In conclusion, our results demonstrate that under chronic hypoxia colon cancer cells developed a pathogenic phenotype characterized by diminished expression of MET and RON. Such a change contributes to the insensitivity of tumor cells towards cytotoxic activities of specifically targeted drugs. Thus, diminished expression of MET and RON under chronic hypoxia is a potential mechanism that affects the effectiveness of targeted therapy in the treatment colon cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 442.

Targeting receptor tyrosine kinases (RTK) with specific mAbs disrupts oncogenic signals and diminishes tumorigenic activities. The RON receptor tyrosine kinase is a member of the MET proto-oncogene family and contributes to motile/invasive phenotypes of colon cancer cells. Here, we studied mAb-induced down-regulation of RON in modulating tumorigenic phenotypes of colon cancer cells. Three mAbs (Zt/g4, Zt/c9 and Zt/f2), recognizing different epitopes in the RON extracellular sequences, were used in various in vitro experiments. Colon cancer SW620 and other cells were used as the model. Treatment of SW620 cells individual mAbs results in transient RON phosphorylation within minutes. However, persistent treatment of cells with Zt/g4 or other mAb causes the down-regulation RON expression as evident by Western blot and cell surface fluorescent analyses. The effect of mAb was in both concentration and time-dependent manners. These activities were not related to antigenic epitopes recognized by individual mAb but highly specific to RON because MET or EGFR expression was not affected. Down regulation of RON impairs intracellular signaling events. Phosphorylation of Erk1/2 and AKT was dramatically reduced after Zt/g4 and other mAb treatment, indicating that the anti-RON mAb has the ability to disrupt downstream signal cascades. Functional studies showed that treatment of SW620 cells with anti-RON mAb affects tumor cell growth in soft agar. It also increases the sensitivity of colon cancer SW620 cells towards chemoagent gemcitabine. In this case, the cytotoxicity of SW620 cells treated with mAbs was significantly increased with reduced IC50 of gemcitabine. In conclusion, our results demonstrated that the persistent treatment of cancer cells with antibodies specific to the RON extracellular domains results in down-regulation of RON expression in colon cancer cells. The reduced RON expression is accompanied with the impaired signaling events and diminished tumorigenic activities. Thus, anti-RON mAb directed targeting could have therapeutic implication for controlling malignant phenotypes of cancer cells (*supported in part by NIH R01 grant Ca91980 and Amarillo Area Foundation of Texas) Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B130.