M2-like tumor-associated macrophages promote epithelial-mesenchymal transition through the transforming growth factor ß/Smad/zinc finger e-box binding homeobox pathway with increased metastatic potential and tumor cell proliferation in lung squamous cell carcinoma.

Epithelial-mesenchymal transition (EMT) promotes primary tumor progression toward a metastatic state. The role of tumor-associated macrophages (TAMs) in inducing EMT in lung squamous cell carcinoma (LUSC) remains unclear. We aimed to clarify the significance of TAMs in relation to EMT in LUSC. We collected 221 LUSC specimens from patients who had undergone surgery. Immunohistochemistry was performed to evaluate M1-like and M2-like TAM distribution and EMT by E-cadherin and vimentin staining. Human LUSC cell lines (H226 and EBC-1) and a human monocyte cell line (THP-1) were used for in vitro experiments. M2-like polarization of TAMs and EMT marker expression in LUSC cells were evaluated by western blotting. The biological behavior of LUSC cells was evaluated by migration, invasion, and cell proliferation assays. Immunohistochemical analysis showed that 166 (75.1%) tumors were E-cadherin-positive and 44 (19.9%) were vimentin-positive. M2-like TAM density in the tumor stroma was significantly associated with vimentin positivity and worse overall survival. Western blotting demonstrated higher levels of CD163, CD206, vascular endothelial growth factor, and transforming growth factor beta 1 (TGF-ß1) in TAMs versus unstimulated macrophages. Furthermore, increased TGF-ß1 secretion from TAMs was confirmed by ELISA. TAM-co-cultured H226 and EBC-1 cells exhibited EMT (decreased E-cadherin, increased vimentin). Regarding EMT-activating transcriptional factors, phosphorylated Smad3 and ZEB-family proteins were higher in TAM-co-cultured LUSC cells than in parental cells. TAM-co-cultured H226 and EBC-1 cells demonstrated enhanced migration and invasion capabilities and improved proliferation. Overall, the present study suggests that TAMs can induce EMT with increased metastatic potential and tumor cell proliferation in LUSC.

A novel cell-based assay for the high-throughput screening of epithelial-mesenchymal transition inhibitors: Identification of approved and investigational drugs that inhibit epithelial-mesenchymal transition.

OBJECTIVES: Lung cancer with distant metastases is associated with a very poor prognosis, and epithelial-mesenchymal transition (EMT) contributes to cancer metastasis. Therefore, elucidation and inhibition of EMT signaling in lung cancer may be a new therapeutic strategy for improving the prognosis of patients. We constructed a high-throughput screening system for EMT inhibitors. Using this system, we aimed to identify compounds that indeed inhibit EMT. MATERIALS AND METHODS: We generated a luciferase reporter cell line using A549 human lung cancer cells and E-cadherin or vimentin as EMT markers. EMT was induced by transforming growth factor ß1 (TGF-ß1), and candidate EMT inhibitors were screened from a library of 2,350 compounds. The selected compounds were further tested using secondary assays to verify the inhibition of EMT and invasive capacity of cells. RESULTS: Values obtained by the assay were adjusted for the number of viable cells and scored by determining the difference between mean values of the positive and negative control groups. Four compounds were identified as novel candidate drugs. Among those, one (avagacestat) and two compounds (GDC-0879 and levothyroxine) improved the expression of E-cadherin and vimentin, respectively, in epithelial cells. GDC-0879 and levothyroxine also significantly inhibited the invasive capacity of cells. CONCLUSION: We systematically screened approved, investigational, and druggable compounds with inhibitory effects using a reporter assay, and identified candidate drugs for EMT inhibition.

Nrf2/p­Fyn/ABCB1 axis accompanied by p­Fyn nuclear accumulation plays pivotal roles in vinorelbine resistance in non­small cell lung cancer.

Adjuvant cisplatin­vinorelbine is a standard therapy for stage II/III lung cancer. However, a poor survival rate of patients with lung cancer is attributed to vinorelbine resistance arising from ATP­binding cassette (ABC) sub­family B member 1 (ABCB1) and phosphorylated Fyn (p­Fyn) overexpression. However, the underlying mechanisms remain unclear. NF­E2­related factor 2 (Nrf2) regulates the ABC family and activates the nuclear transport of Fyn. The present study evaluated the roles of the Nrf2/p­Fyn/ABCB1 axis in vinorelbine­resistant (VR) cells and clinical samples. To establish VR cells, H1299 cells were exposed to vinorelbine, and the intracellular reactive oxygen species (ROS) level in the H1299 cells was determined using a DCFH­DA assay. The total and subcellular expression of Nrf2, ABCB1 and p­Fyn in VR cells was evaluated. Immunofluorescence was used to detect the subcellular localization of p­Fyn in VR cells. A cell viability assay was used to examine whether the sensitivity of VR cells to vinorelbine is dependent on Nrf2 activity. Immunohistochemistry was performed on 104 tissue samples from patients with lung cancer who underwent surgery followed by cisplatin­vinorelbine treatment. The results revealed that persistent exposure to vinorelbine induced intracellular ROS formation in H1299 cells. p­Fyn was localized in the nucleus, and ABCB1 and Nrf2 were overexpressed in VR cells. ABCB1 expression was dependent on Nrf2 downstream activation. The decreased expression of Nrf2 restored the sensitivity of VR cells to vinorelbine. In the surgical samples, Nrf2 and ABCB1 were associated with disease­free survival, and p­Fyn was associated with overall survival (P<0.05). On the whole, the present study demonstrates that Nrf2 upregulates ABCB1 and, accompanied by the nuclear accumulation of p­Fyn, induces vinorelbine resistance. These findings may facilitate the development of drug resistance prevention strategies or new drug targets against non­small cell lung cancer.

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors as a first-line treatment for postoperative recurrent and EGFR-mutated non-small-cell lung cancer.

OBJECTIVES: To clarify survival outcomes and prognostic factors of patients receiving epidermal growth factor receptor (EGFR) - tyrosine kinase inhibitors (TKIs) as first-line treatment for postoperative recurrence. METHODS: A retrospective chart review was performed to identify consecutive patients who received EGFR-TKIs as first-line treatment for postoperative recurrence of non-small-cell lung cancer (NSCLC) harbouring EGFR gene mutations at our institution between August 2002 and October 2020. Therapeutic response, adverse events, progression-free survival (PFS) and overall survival (OS) were investigated. Survival outcomes were assessed using the Kaplan-Meier analysis. The Cox proportional hazards model was used for univariable and multivariable analyses. RESULTS: Sixty-four patients were included in the study. The objective response and disease control rates were 53% and 92%, respectively. Grade 3 or greater adverse events were noted in 4 (6.3%) patients, including 1 patient (1.6%) of interstitial pneumonia. The median follow-up period was 28.5 months (range 3-202 months). The total number of events was 43 for PFS and 23 for OS, respectively. The median PFS was 18 months, and the median OS was 61 months after EGFR-TKI treatment. In multivariable analysis, osimertinib showed a tendency to prolong PFS [hazard ratio (HR) 0.41, 95% confidence interval (CI) 0.12-1.1; P = 0.071], whereas the micropapillary component was significantly associated with shorter OS (HR 2.1, 95% CI 1.02-6.9; P = 0.045). CONCLUSIONS: EGFR-TKIs as first-line treatment appeared to be a reasonable treatment option in selected patients with postoperative recurrent EGFR-mutated NSCLC. Osimertinib and the micropapillary component may be prognostic factors.

Thoracoscopic partial resection without using a stapler. (complete republication).

Thoracoscopic partial pulmonary resection for small peripheral nodules without using a stapler has been introduced to our hospital. After partial resection was performed with electrocautery, two different methods of surface sealing were used: a coagulation method (C method) with Soft Coagulation alone, and a coagulation-suturing method (CS method) with Soft Coagulation combined with continuous suturing. The clinical outcomes of the two methods were retrospectively compared in this study. The C method was used in 19 lesions of 18 cases, and the CS method was used in 20 lesions of 19 cases. Primary lung cancer was the most frequent diagnosis (22 lesions of 21 cases). There were no differences between the two groups in the size and depth of the lesions. Operative time was longer with the CS method than with the C method. Postoperative air leakage was a complication in 4 cases with the C method, and one of them required re-do surgery, whereas only one case with the CS method had temporary air leakage. Postoperative computed tomography showed cavitation in 3 C method cases and 5 CS method cases, all without related symptoms. There were no local recurrences at resected sites. In conclusion, the C method was technically easy to perform, but air leakage may be prolonged after surgery. The CS method may have the advantage of causing less air leakage than the C method, but mastering the technique is important to shorten operative time.

Rib resection using a pneumatic high-speed power drill system for lung cancer with chest wall invasion: our clinical experience.

Rib resection for chest wall tumors, including lung cancer with chest wall invasion, is usually performed through open thoracotomy. Resection of part of the external rib cage requires an elongated or additional incision depending on the location and extension of the tumor, eventually becoming more invasive to patients. We recently introduced a technique of rib resection using a pneumatic high-speed power drill system known as "air tome". This novel technique is easy to perform through a small incision or even via video-assisted thoracoscopic surgery (VATS) in selected patients. We present our clinical experience and discuss the usefulness of this technique for rib resection in patients with lung cancer and chest wall invasion.

Prognostic value of body mass index and change in body weight in postoperative outcomes of lung cancer surgery.

OBJECTIVES: Nutritional status is associated with an effect on oncological outcomes. However, the effect of nutritional status on postoperative survival in lung cancer has not been well studied. We retrospectively analysed and evaluated the effect of preoperative body mass index (BMI) and changes in body weight on postoperative outcomes of lung cancer surgery. METHODS: A total of 1311 patients with non-small-cell lung cancer who underwent surgery between January 2001 and December 2011 were included in this study. Preoperative body weight at 4-12 weeks prior to surgery was obtained in 737 patients and the ratio of change in body weight was calculated. RESULTS: The patients were classified into four groups as follows: underweight (BMI < 18.5), normal weight (BMI from ≥18.5 to <25), overweight (BMI from ≥25 to <30) and obese (BMI ≥ 30). Postoperative survival curves of the BMI groups showed that the underweight group had a poorer prognosis than the other groups, especially for disease-free survival (DFS) (P = 0.03). Univariate and adjusted survival analyses using Cox's proportional hazards regression model showed that low BMI was a significantly poor prognostic factor in overall survival (OS) (P = 0.03 and P = 0.02, respectively) and DFS (P < 0.01 and P < 0.01, respectively). Among the BMI groups, the underweight group had a significant worse prognosis than the other groups for DFS in univariate and adjusted analyses (P = 0.04 and P < 0.01, respectively). With regard to changes in body weight, patients with a body weight loss of 3.7% or greater had a significantly poorer prognosis for OS and DFS in univariate analysis and for DFS in adjusted analyses compared with the other patients. Regarding short-term outcomes, the weight loss group had a significantly longer postoperative hospital stay than the non-weight loss group (P = 0.02) and postoperative 90-day mortality was significantly lower in the normal weight group than in the underweight group (P = 0.03). CONCLUSIONS: Low BMI and significant body weight loss before surgery have a negative effect on surgical outcomes for patients with non-small-cell lung cancer.

Clinical experience of sleeve lobectomy with bronchoplasty using a continuous absorbable barbed suture.

Anastomosis in bronchoplasty is usually performed using interrupted sutures, which are considered safe, reliable, and secure. However, placing interrupted sutures can be complex and time-consuming. There have been recent reports of continuous suturing using standard suture materials in bronchoplasty. We have experienced four cases of sleeve lobectomy with bronchial anastomosis in continuous fashion using a novel absorbable barbed suture device, the V-Loc™ wound closure device (Covidien, USA), which facilitates secure wound closure without knot-tying. Two patients underwent sleeve upper lobectomy and two underwent sleeve upper-middle lobectomy. Surgical approach was completely thoracoscopic in one patient and open in three. There were no intraoperative difficulties such as cutting or loosening, and a leak test was negative in all cases. One patient had pneumonia postoperatively and developed anastomotic stenosis 4 months after surgery, which did not require treatment. All patients were alive, without local recurrence, at a mean follow-up of 11.5 months postoperatively.

Clinical relevance of decreased oxygen saturation during 6-min walk test in preoperative physiologic assessment for lung cancer surgery.

OBJECTIVE: The Japanese Association for Chest Surgery (JACS) has released guidelines on preoperative physiologic assessment for lung cancer surgery. However, cardiopulmonary exercise testing (CPET), which is recommended for patients with poor pulmonary function, is available only in limited institutions. We investigated the possibility of 6-min walk test (6MWT) as a substitute of maximum oxygen consumption test (VO(2)max) on preoperative physiologic assessment for lung cancer surgery. METHODS: The relationship between VO(2)max and 6MWT was retrospectively analyzed in 51 subjects other than lung cancer patients. Following the preliminary analysis, we modified the risk assessment in the JACS guidelines by substituting 6MWT for VO(2)max, and patients who underwent lung cancer surgery were retrospectively assessed using the modified assessment. RESULTS: Analysis of the correlation between VO(2)max and 6MWT revealed VO(2)max to be significantly correlated to minimum SpO(2) (SpO(2)min) and maximum decrease in SpO(2) (ΔSpO(2)) during 6MWT. Receiver operating characteristic analysis revealed that SpO(2)min and ΔSpO(2) were predictable for a VO(2)max of 15 mL/kg/min, which is the borderline between the average- and increased-risk groups in the JACS guidelines. A total of 1,066 patients were assigned to the average- or increased-risk group according to the modified JACS guidelines using the criteria of SpO(2)min < 91 % and ΔSpO(2) > 4 %. The increased-risk group was significantly inferior to the average-risk group in Home Oxygen Therapy induction rate, cardiopulmonary-related 30- and 90-day mortality (p < 0.001). CONCLUSIONS: In clinical practice, decreased saturation during 6MWT may be simple and substitutive for CPET in risk assessment for lung cancer surgery using the JACS guidelines.