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Background Approximately 20% of lung adenocarcinoma (LUAD) is negative for the lineage-specific oncogene Thyroid transcription factor 1 (TTF-1) and exhibits worse clinical outcome with a low frequency of actionable genomic alterations. To identify molecular features associated with TTF-1–negative LUAD, we compared the transcriptomic and proteomic profiles of LUAD cell lines. SRGN , a chondroitin sulfate proteoglycan Serglycin, was identified as a markedly overexpressed gene in TTF-1–negative LUAD. We therefore investigated the roles and regulation of SRGN in TTF-1–negative LUAD. Methods Proteomic and metabolomic analyses of 41 LUAD cell lines were done using mass spectrometry. The function of SRGN was investigated in 3 TTF-1–negative and 4 TTF-1–positive LUAD cell lines and in a syngeneic mouse model (n = 5 to 8 mice per group). Expression of SRGN was evaluated in 94 and 105 surgically resected LUAD tumor specimens using immunohistochemistry. All statistical tests were 2-sided. Results SRGN was markedly overexpressed at mRNA and protein levels in TTF-1–negative LUAD cell lines (P < .001 for both mRNA and protein levels). Expression of SRGN in LUAD tumor tissue was associated with poor outcome (hazard ratio = 4.22, 95% confidence interval = 1.12 to 15.86, likelihood ratio test, P = .03), and with higher expression of Programmed cell death 1 ligand 1 (PD-L1) in tumor cells and higher infiltration of Programmed cell death protein 1–positive lymphocytes. SRGN regulated expression of PD-L1 as well as proinflammatory cytokines, including Interleukin-6, Interleukin-8, and C-X-C motif chemokine 1 in LUAD cell lines; increased migratory and invasive properties of LUAD cells and fibroblasts; and enhanced angiogenesis. SRGN was induced by DNA demethylation resulting from Nicotinamide N-methyltransferase–mediated impairment of methionine metabolism. Conclusions Our findings suggest that SRGN plays a pivotal role in tumor–stromal interaction and reprogramming into an aggressive and immunosuppressive tumor microenvironment in TTF-1–negative LUAD.

Background: Early-stage lung adenocarcinoma (LUAD) patients have substantial risk for recurrence and disease-related death. Cisplatin-based adjuvant chemotherapy remains the standard for care of LUAD patients who have undergone surgical resection with a high risk of recurrence. However, adjuvant chemotherapy is associated with increased risk of toxicity including chemotherapy-related death, with only a modest survival benefit. Therefore, there is an unmet need of biomarkers for assessment and identification of those in an early stage who would likely benefit from adjuvant chemotherapy. Circulating miRNAs are stably present in blood and potentially reflect different expressions in cancerous and non-cancerous tissues, making them attractive biomarkers. The purpose of this study was to identify circulating miRNAs useful for predicting recurrence in early-stage LUAD. Materials and Methods: miRNA microarray analysis was performed with pooled pretreatment plasma samples from stage I LUAD patients who developed recurrence within two years after curative surgery or remained recurrence free over a six-year follow-up period, as well as from healthy controls. miRNA biomarker candidates were assayed in two independent plasma sample sets from 85 stage I LUAD (validation set) and from 57 stage I and II LUAD (test set) patients. Results: Based on miRNA microarray data and previous reports, predictive performance of miR-23a-3p, miR-23b-3p, miR-191-5p, miR-185-5p, miR-151a-3p, miR-320c, miR-21-5p, miR-125b-5p, miR-30d-5p, and miR-197-3p was evaluated in the validation set. Plasma levels of miR-23a-3p, miR-185-5p, miR-320c, miR-21-5p, miR-125b-5p, miR-30d-5p, and miR-197-3p were significantly higher in those with recurrence as compared to those without. A miRNA panel comprised of miR-23a-3p, miR-320c, and miR-125b-5p was developed based on a logistic regression, with yielding an AUC of 0.776 (95% confidence interval [CI] = 0.660 to 0.893). The three-miRNA panel with fixed coefficients yielded an AUC of 0.804 (95% CI = 0.688 to 0.920) with a sensitivity of 45.8% at 95% specificity in the test set. The miRNA panel score was a significant and independent factor for predicting disease-free survival (DFS; P < 0.001, HR = 1.64, 95% CI = 1.51-4.22) and overall survival (OS; P = 0.001, HR = 1.51, 95% CI = 1.17-1.94). Conclusion: This circulating miRNA panel may serve as a noninvasive blood test for predicting DFS and OS in early-stage LUAD patients. Our findings provide rationale for further investigation to stratify early-stage LUAD patients using blood-based biomarkers to increase the ability to provide more personalized care. Citation Format: Mei-Chee Tai, Leonidas E. Bantis, Gargy Parhy, Taketo Kato, Ichidai Tanaka, Chi-Wan Chow, Junya Fujimoto, Carmen Behrens, Tetsunari Hase, Koji Kawaguchi, Johannes F. Fahrmann, Edwin Ostrin, Kohei Yokoi, Toyofumi F. Chen-Yoshikawa, Yoshinori Hasegawa, Samir M. Hanash, Ignacio I. Wistuba, Ayumu Taguchi. A circulating microRNA panel predicts recurrence and survival in early-stage lung adenocarcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3744.

Simple Summary Although pathologic complete response (pCR) to neoadjuvant chemoradiation (nCRT) in locally advanced rectal cancer (LARC) is associated with better outcomes, a subset of tumors exhibit resistance to nCRT. Therefore, there is a need of biomarkers to predict the nCRT response and increment efforts for personalized therapeutic options. To this end, we analyzed pretreatment plasma proteome of a mouse model of rectal cancer treated with concurrent chemoradiation, resulting in identification and validation of plasma VEGFR3 as a potential predicting biomarker. In addition, plasma levels of EGFR and COX2, previously validated tissue-based predicting biomarkers, were significantly higher in non-pCR than pCR LARC patients, indicating that EGFR and COX2 can also serve as blood-based biomarkers. The performance of the biomarker panel combining VEGFR3, EGFR, and COX2 were significantly improved compared to that of each marker alone, providing a rationale for further integration and refinement of the biomarker panel and validation in the larger sample sets. Abstract The current standard of care for patients with locally advanced rectal cancer (LARC) is neoadjuvant chemoradiation (nCRT) followed by total mesorectal excision surgery. However, the response to nCRT varies among patients and only about 20% of LARC patients achieve a pathologic complete response (pCR) at the time of surgery. Therefore, there is an unmet need for biomarkers that could predict the response to nCRT at an early time point, allowing for the selection of LARC patients who would or would not benefit from nCRT. To identify blood-based biomarkers for prediction of nCRT response, we performed in-depth quantitative proteomic analysis of pretreatment plasma from mice bearing rectal tumors treated with concurrent chemoradiation, resulting in the quantification of 567 proteins. Among the plasma proteins that increased in mice with residual rectal tumor after chemoradiation compared to mice that achieved regression, we selected three proteins (Vascular endothelial growth factor receptor 3 [VEGFR3], Insulin like growth factor binding protein 4 [IGFBP4], and Cathepsin B [CTSB]) for validation in human plasma samples. In addition, we explored whether four tissue protein biomarkers previously shown to predict response to nCRT (Epidermal growth factor receptor [EGFR], Ki-67, E-cadherin, and Prostaglandin G/H synthase 2 [COX2]) also act as potential blood biomarkers. Using immunoassays for these seven biomarker candidates as well as Carcinoembryonic antigen [CEA] levels on plasma collected before nCRT from 34 patients with LARC (6 pCR and 28 non-pCR), we observed that levels of VEGFR3 (p = 0.0451, AUC = 0.720), EGFR (p = 0.0128, AUC = 0.679), and COX2 (p = 0.0397, AUC = 0.679) were significantly increased in the plasma of non-pCR LARC patients compared to those of pCR LARC patients. The performance of the logistic regression model combining VEGFR3, EGFR, and COX2 was significantly improved compared with the performance of each biomarker, yielding an AUC of 0.869 (sensitivity 43% at 95% specificity). Levels of VEGFR3 and EGFR were significantly decreased 5 to 7 months after tumor resection in plasma from 18 surgically resected rectal cancer patients, suggesting that VEGFR3 and EGFR may emanate from tumors. These findings suggest that circulating VEGFR3 can contribute to the prediction of the nCRT response in LARC patients together with circulating EGFR and COX2.