Clinical Significance of SIRPα Expression on Tumor-Associated Macrophages in Patients with Lung Squamous Cell Carcinoma.

BACKGROUND: Signal-regulatory protein alpha (SIRPα) is an immune checkpoint molecule expressed on macrophages that functions to inhibit phagocytosis by binding to CD47 expressed on tumor cells. SIRPα has attracted increasing attention as a novel target for cancer immunotherapy; however, the expression and immune function of SIRPα in lung squamous cell carcinoma (LUSC) remain unclear. Therefore, this study aimed to identify the clinical importance of SIRPα expression in LUSC and to explore the factors that elevate SIRPα expression. PATIENTS AND METHODS: Primary LUSC specimens surgically resected from 172 patients underwent immunohistochemical evaluation of the association of SIRPα expression on tumor-associated macrophages with clinicopathological features and clinical outcomes. Furthermore, we analyzed the association of SIRPα expression with tumor-infiltrating lymphocytes and the expression of programmed cell death ligand 1 (PD-L1). In vitro, monocytes were treated with cytokines, and SIRPα protein expression was assessed by flow cytometry. RESULTS: There were no differences in SIRPα expression and clinicopathological factors. High SIRPα expression was significantly associated with PD-L1-positive expression, and high CD8, PD-1, and CD163 expression. The high SIRPα expression group showed significantly shorter recurrence-free survival (RFS) and overall survival (OS). On multivariate analysis, high SIRPα expression was an independent poor prognostic factor for RFS and OS. The expression of SIRPα protein in monocytes was upregulated by treatment with IFNγ. CONCLUSION: Our analysis revealed that high SIRPα expression significantly predicts poor prognosis in patients with surgically resected LUSC.

Clinical and Prognostic Significance of Glutathione Peroxidase 2 in Lung Adenocarcinoma.

BACKGROUND: Glutathione peroxidase 2 (GPX2) is an antioxidant enzyme with an important role in tumor progression in various cancers. However, the clinical significance of GPX2 in lung adenocarcinoma has not been clarified. METHODS: Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to analyze GPX2 mRNA expression. Then, we conducted immunohistochemistry (IHC) to assess GPX2 expression in specimens acquired from 351 patients with lung adenocarcinoma who underwent surgery at Kyushu University from 2003 to 2012. We investigated the association between GPX2 expression and clinicopathological characteristics and further analyzed the prognostic relevance. RESULTS: qRT-PCR revealed that GPX2 mRNA expression was notably higher in tumor cells than in normal tissues. IHC revealed that high GPX2 expression (n = 175, 49.9%) was significantly correlated with male sex, smoking, advanced pathological stage, and the presence of pleural, lymphatic, and vascular invasion. Patients with high GPX2 expression exhibited significantly shorter recurrence-free survival (RFS) and overall survival. Multivariate analysis identified high GPX2 expression as an independent prognostic factor of RFS. CONCLUSIONS: GPX2 expression was significantly associated with pathological malignancy. It is conceivable that high GPX2 expression reflects tumor malignancy. Therefore, high GPX2 expression is a significant prognostic factor of poor prognosis for completely resected lung adenocarcinoma.

Maximum resistance pressure at the time of lung tissue rupture after porcine lung transection using automatic linear staplers with different reinforcement methods.

PURPOSES: Polyglycolic acid (PGA) sheets, fibrin glue, and staple line reinforcement are frequently used to prevent air leakage during lung resection. However, the optimal staple-line reinforcement method remains unclear. METHODS: Cranial lung lobes of pigs were used to evaluate different staple line reinforcement methods (n = 6). Ventilator-assisted manometry was used to measure the maximum resistance pressure at the time of rupture of the lung tissue after stapling. RESULTS: The mean maximum resistance pressures at the time of lung tissue rupture after using the stapler alone, stapler with PGA sheet and fibrin glue, and stapler with reinforcement were 38.0 cmH2O, 51.3 cmH2O, and 62.7 cmH2O, respectively. A significant increase in the maximum resistance pressure was observed with stapler reinforcement (P < 0.001), while the differences between the other groups were not statistically significant (P = 0.055, P = 0.111). A histological assessment revealed disruption of alveolar structures near the needle-stitching site in the stapler alone, and in the stapler with PGA sheet and fibrin glue groups. Pleural rupture near the staple line was observed in the stapler with reinforcement group. CONCLUSIONS: The maximum resistance pressure before air leakage was significantly higher when using a stapler with reinforcement than when using a stapler alone.

MicroRNA-326 negatively regulates CD155 expression in lung adenocarcinoma.

Treatment with immune checkpoint inhibitors induces a durable response in some patients with non-small-cell lung cancer, but eventually gives rise to drug resistance. Upregulation of CD155 expression is implicated as one mechanism of resistance to programmed death receptor-1 (PD-1)/PD-1 ligand (PD-L1) inhibitors, and it is therefore important to characterize the mechanisms underlying regulation of CD155 expression in tumor cells. The aim of this study was to identify microRNAs (miRNAs) that might regulate CD155 expression at the posttranscriptional level in lung cancer. Comprehensive miRNA screening with target prediction programs and a dual-luciferase reporter assay identified miR-346, miR-328-3p, miR-326, and miR-330-5p as miRNAs that bind to the 3'-UTR of CD155 mRNA. Forced expression of these miRNAs suppressed CD155 expression in lung cancer cell lines. Immunohistochemical staining of CD155 in tissue specimens from 57 patients with lung adenocarcinoma revealed the median tumor proportion score for CD155 to be 68%. The abundance of miR-326 in these specimens with a low level of CD155 expression was significantly greater than in specimens with a high level (p < 0.005). Our results thus suggest that miR-326 negatively regulates CD155 expression in lung adenocarcinoma and might therefore play a role in the development of resistance to PD-1/PD-L1 inhibitors.

Preventive effect of tertiary lymphoid structures on lymph node metastasis of lung adenocarcinoma.

BACKGROUND: Ectopic lymphoid formations are called tertiary lymphoid structures (TLSs). TLSs in cancer have been reported to be associated with good prognosis and immunotherapy response. However, the relationship between TLSs and lymph node (LN) metastasis is unclear. METHODS: We analyzed 218 patients with radically resected lung adenocarcinoma. TLSs were defined as the overlap of T cell zone and B cell zone. Granzyme B + cells were defined as cytotoxic lymphocytes. We evaluated phenotypes of lymphocytes in TLSs, tumor-infiltrating lymphocytes (TILs) and LNs by immunohistochemistry. We divided the patients into mature TLS (DC-Lamp high) and immature TLS (DC-Lamp low) groups. The relationship between TLS maturation and clinicopathological factors was analyzed. RESULTS: The mature TLS group was associated with significantly lower frequency of LN metastasis (P < 0.0001) and early cancer stage (P = 0.0049). The mature TLS group had significantly more CD8 + (P = 0.0203) and Foxp3 + (P = 0.0141) cells in TILs than the immature TLS group had. Mature TLSs were independently associated with a favorable overall survival (hazard ratio [HR] = 0.17, P = 0.0220) and disease-free survival (HR = 0.54, P = 0.0436). Multivariate analysis showed that mature TLS was an independent low-risk factor for LN metastasis (odds ratio = 0.06, P = 0.0003). The number of cytotoxic lymphocytes in LNs was higher in the mature TLS group than in the immature group (20.0 vs. 15.1, P = 0.017). CONCLUSION: Mature TLSs were associated with an increased number of cytotoxic lymphocytes in draining LNs, a lower frequency of LN metastasis, and favorable outcomes. Mature TLSs may support antitumor immunity by lymphocyte activation.

Prognostic Impact of C-Reactive Protein-to-Lymphocyte Ratio in Non-small Cell Lung Cancer: A Propensity Score-Matching Analysis.

BACKGROUND: Many inflammatory and nutritional markers have been used to predict prognosis in lung cancer. The C-reactive protein (CRP)-to-lymphocyte ratio (CLR) is a useful prognostic factor in various cancers. However, the prognostic value of preoperative CLR in patients with non-small cell lung cancer (NSCLC) remains to be established. We examined the significance of the CLR compared with known markers. METHODS: A total of 1380 surgically resected NSCLC patients treated at two centers were recruited and divided into derivation and validation cohorts. After CLRs were calculated, patients were classified into high and low CLR groups based on the cutoff value determined by receiver operating characteristics curve analysis. Subsequently, we determined the statistical associations of the CLR with clinicopathological factors and prognosis and further analyzed its prognostic impact by propensity-score matching. RESULTS: Of all the inflammatory markers examined, CLR yielded the highest area-under-the-curve value. The prognostic impact of CLR remained significant after propensity-score matching. Prognosis was significantly worse in the high-CLR group than in the low-CLR group (5-year, disease-free survival [DFS]: 58.1% vs. 81.9%, P < 0.001; 5-year overall survival [OS]: 72.1% vs. 91.2%, P < 0.001). The results were confirmed in the validation cohorts. Multivariable analysis also showed high CLR as an independent factor for both DFS and OS (DFS: hazard ratio [HR] 1.42, P = 0.027; OS: HR 1.95, P = 0.0037). CONCLUSIONS: Preoperative CLR is a useful marker for predicting the prognosis of NSCLC patients who have undergone surgery.

Transducin Beta-Like 2 is a Potential Driver Gene that Adapts to Endoplasmic Reticulum Stress to Promote Tumor Growth of Lung Adenocarcinoma.

BACKGROUND: Endoplasmic reticulum (ER) stress has a close relation with cancer progression. Blocking the adaptive pathway of ER stress could be an anticancer strategy. Here, we identified an ER stress-related gene, Transducin beta-like 2 (TBL2), an ER-localized type I transmembrane protein, on increased chromosome 7q as a candidate driver gene of lung adenocarcinoma (LUAD). METHODS: The association between TBL2 mRNA expression and prognostic outcomes and clinicopathological factors was analyzed using The Cancer Genome Atlas (TCGA) datasets of LUAD and lung squamous cell carcinoma (LUSC). Localization of TBL2 in tumor tissues was observed by immunohistochemical staining. Gene set enrichment analysis (GSEA) was conducted using TCGA dataset. In vitro cell proliferation assays were performed using TBL2 knockdown LUAD cells, LUSC cells, and LUAD cells overexpressing TBL2. Apoptosis and ATF4 expression (ER stress marker) were evaluated by western blotting. RESULTS: TBL2 was overexpressed in LUAD and LUSC cells. Multivariate analysis indicated high TBL2 mRNA expression was an independent poor prognostic factor of LUAD. GSEA revealed high TBL2 expression was positively correlated to the ER stress response in LUAD. TBL2 knockdown attenuated LUAD cell proliferation under ER stress. TBL2 inhibited apoptosis in LUAD cells under ER stress. TBL2 knockdown reduced ATF4 expression under ER stress. CONCLUSIONS: TBL2 may be a novel driver gene that facilitates cell proliferation, possibly by upregulating ATF4 expression followed by adaptation to ER stress, and it is a poor prognostic biomarker of LUAD.

Granzyme B (GZMB)-Positive Tumor-Infiltrating Lymphocytes in Lung Adenocarcinoma: Significance as a Prognostic Factor and Association with Immunosuppressive Proteins.

BACKGROUND: Granzyme B (GZMB) is a serine protease produced by cytotoxic lymphocytes that reflects the activity of anti-tumor immune responses in tumor-infiltrating lymphocytes (TILs); however, the prognostic significance of GZMB+ TILs in lung adenocarcinoma is poorly understood. METHODS: We analyzed 273 patients with pathological stage (pStage) I-IIIA lung adenocarcinoma who underwent surgery at Kyushu University from 2003 to 2012. We evaluated GZMB+ TIL counts by immunohistochemistry. We set the cut-off values at 12 cells/0.04 mm2 for GZMB+ TILs and divided the patients into GZMB-High (n = 171) and GZMB-Low (n = 102) groups. Then, we compared the clinicopathological characteristics of the two groups and clinical outcomes. Programmed cell death ligand-1 (PD-L1) and indoleamine 2,3-dioxygenase 1 (IDO1) expression in tumor cells was also evaluated, and combined prognostic analyses of GZMB+ TILs with PD-L1 or IDO1 were performed. RESULTS: GZMB-Low was significantly associated with pStage II-III, PD-L1 positivity, and IDO1 positivity. Disease-free survival (DFS) and overall survival (OS) in the GZMB-Low group were significantly worse than in the GZMB-High group. In multivariable analysis, GZMB-Low was an independent prognostic factor for both DFS and OS. Furthermore, combined prognostic analyses of GZMB+ TILs with PD-L1 or IDO1 showed that GZMB-Low with high expression of these immunosuppressive proteins had the worst prognosis. CONCLUSIONS: We analyzed GZMB+ TIL counts in lung adenocarcinoma and elucidated its prognostic significance and association with PD-L1 and IDO1. GZMB+ TIL counts might reflect the patient's immunity against cancer cells and could be a useful prognostic marker of lung adenocarcinoma.

Smoking enhances the expression of angiotensin-converting enzyme 2 involved in the efficiency of severe acute respiratory syndrome coronavirus 2 infection.

Smoking is one of the risk factors most closely related to the severity of coronavirus disease 2019 (COVID-19). However, the relationship between smoking history and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infectivity is unknown. In this study, we evaluated the ACE2 expression level in the lungs of current smokers, ex-smokers, and nonsmokers. The ACE2 expression level of ex-smokers who smoked cigarettes until recently (cessation period shorter than 6 months) was higher than that of nonsmokers and ex-smokers with a long history of nonsmoking (cessation period longer than 6 months). We also showed that the efficiency of SARS-CoV-2 infection was enhanced in a manner dependent on the angiotensin-converting enzyme 2 (ACE2) expression level. Using RNA-seq analysis on the lungs of smokers, we identified that the expression of inflammatory signaling genes was correlated with ACE2 expression. Notably, with increasing duration of smoking cessation among ex-smokers, not only ACE2 expression level but also the expression levels of inflammatory signaling genes decreased. These results indicated that smoking enhances the expression levels of ACE2 and inflammatory signaling genes. Our data suggest that the efficiency of SARS-CoV-2 infection is enhanced by smoking-mediated upregulation of ACE2 expression level.

Identification of SLC38A7 as a Prognostic Marker and Potential Therapeutic Target of Lung Squamous Cell Carcinoma.

BACKGROUND: No effective molecular targeted therapy has been established for SCC. We conducted a comprehensive study of SCC patients using RNA-sequencing and TCGA dataset to clarify the driver oncogene of SCC. METHOD: Forty-six samples of 23 patients were totally analyzed with RNA-sequencing. We then searched for candidate-oncogenes of SCC using the TCGA database. To identify candidate oncogenes, we used the following 2 criteria: (1) the genes of interest were overexpressed in tumor tissues of SCC patients in comparison to normal tissues; and (2) using an integrated mRNA expression and DNA copy number profiling analysis using the TCGA dataset, the DNA copy number of the genes was positively correlated with the mRNA expression. RESULT: We identified 188 candidate-oncogenes. Among those, the high expression of SLC38A7 was a strong prognostic marker that was significantly associated with a poor prognosis in terms of both overall survival (OS) and recurrence-free survival in the TCGA dataset (P < 0.05). Additionally, 202 resected SCC specimens were also subjected to an immunohistochemical analysis. Patients with the high expression of SLC38A7 (alternative name is sodium-coupled amino acid transporters 7) protein showed significantly shorter OS in comparison to those with the low expression of SLC38A7 protein [median OS 3.9 years (95% confidence interval, 2.4-6.4 years) vs 2.2 years (95% confidence interval, 1.9-4.1 years); log rank test: P = 0.0021]. CONCLUSION: SLC38A7, which is the primary lysosomal glutamine transporter required for the extracellular protein-dependent growth of cancer cells, was identified as a candidate therapeutic target of SCC.

The prognostic impact of combined pulmonary fibrosis and emphysema in patients with clinical stage IA non-small cell lung cancer.

PURPOSE: We evaluated the long-term outcomes of clinical stage IA non-small cell lung cancer (NSCLC) patients with combined pulmonary fibrosis and emphysema (CPFE) who underwent lobectomy. METHODS: We reviewed the chest computed tomography (CT) findings and divided the patients into normal, fibrosis, emphysema and CPFE groups. We evaluated the relationships among the CT findings, the clinicopathological findings and postoperative survival. RESULTS: The patients were classified into the following groups based on the preoperative chest CT findings: normal lung, n = 187; emphysema, n = 62; fibrosis, n = 8; and CPFE, n = 17. The patients with CPFE were significantly older, more likely to be men and smokers, had a higher KL-6 level and lower FEV 1.0% value and had a higher rate of squamous cell carcinoma. The 5-year overall survival (OS) and disease-free survival rates were as follows: normal group, 82.5 and 76.8%; emphysema group, 80.0 and 74.9%; fibrosis group, 46.9 and 50%; and CPFE group, 36.9 and 27.9%, respectively (p < 0.01). A univariate and multivariate analysis determined that the pathological stage and CT findings were associated with OS. CONCLUSIONS: CPFE is a significantly unfavorable prognostic factor after lobectomy, even in early-stage NSCLC patients with a preserved lung function.

Osimertinib reactivated immune-related colitis after treatment with anti-PD1 antibody for non-small cell lung cancer.

We reported a case of relapsing immune-related colitis (initially caused by nivolumab) following osimertinib therapy for lung adenocarcinoma. A 45-year-old female who had never smoked was diagnosed with adenocarcinoma of the lung and underwent surgical resection. Four years after surgical resection, she was diagnosed with recurrent disease and was eventually treated with nivolumab as third-line therapy. One month after the completion of nivolumab therapy, the patient reported abdominal pain and frequent diarrhea. We diagnosed immune-related colitis and started oral prednisolone. However, the steroid therapy was ineffective, so the patient was administered infliximab and an increased dose of prednisolone. Her symptoms subsequently resolved, and her mucosal lesions improved. Six months after the last administration of nivolumab, osimertinib was initiated as fourth-line therapy, but 3 days later, the patient developed blood in the stool and frequent diarrhea. Osimertinib treatment was discontinued, given the possibility that it had reactivated the patient's immune-related colitis. We subsequently re-administered oral prednisolone (2 mg/kg/day), and the colitis resolved within a few weeks.

Post-recurrence survival of elderly patients 75 years of age or older with surgically resected non-small cell lung cancer.

PURPOSE: The purpose of this study was to evaluate the outcomes of elderly patients 75 years of age or older with recurrent non-small cell lung cancer (NSCLC). METHODS: A total of 1237 consecutive patients with NSCLC underwent pulmonary resection at our institution. Of these patients, 280 experienced postoperative recurrence. The rate of the post-recurrence survival and predictors were analyzed independently in a group of younger patients (<75 years) and a group of elderly patients (≥75 years). RESULTS: There were 215 younger patients (<75 years) and 65 elderly (≥75 years) patients at the time of diagnosis of recurrence. The median post-recurrence survival time and the five-year survival rate of all cases were 25 months and 20.8%, respectively. There were no significant survival differences between the younger and elderly groups (p = 0.20). A univariate analysis determined that gender, Eastern Cooperative Oncology Group performance status, smoking status, histological type and epithelial growth factor receptor (EGFR) mutation status were factors influencing the post-recurrence survival among the elderly patients. In addition, a multivariate analysis determined the EGFR mutation status to be an independent prognostic factor for the post-recurrence survival. CONCLUSIONS: Elderly patients 75 years of age or older in this study achieved satisfactory long-term outcomes.

Gemcitabine and vinorelbine as second-line or beyond treatment in patients with malignant pleural mesothelioma pretreated with platinum plus pemetrexed chemotherapy.

BACKGROUND: Malignant pleural mesothelioma (MPM) is an aggressive neoplasm that responds poorly to chemotherapy. Although treatment with pemetrexed in combination with cisplatin serves as first-line chemotherapy for MPM, the optimal second-line and beyond therapy has not yet been fully examined. METHODS: Between March 2008 and October 2011, 17 consecutive Japanese patients pretreated with at least one regimen of platinum plus pemetrexed chemotherapy received gemcitabine and vinorelbine. Responses, survival time, and toxicity were retrospectively evaluated. RESULTS: Response [partial response (PR) + complete response (CR)] and disease control [stable disease (SD) + PR + CR] rates were 18 and 82 %, respectively. The median progression-free survival (PFS) after combination chemotherapy was 6.0 months, whereas the median overall survival (OS) was 11.2 months. Grade 3 or 4 neutropenia and anemia were observed in 41 and 29 % of patients, respectively, and one patient experienced febrile neutropenia. Grade 3 or 4 nonhematologic toxicities included constipation (6 %) and phlebitis (6 %). CONCLUSION: Combination chemotherapy using gemcitabine with vinorelbine was shown to have moderate activity in Japanese MPM patients pretreated with platinum plus pemetrexed chemotherapy. A further multicenter phase II trial is warranted to confirm the efficacy and safety of this combination treatment.