Yoichi Ohtaki

Podoplanin-Positive Fibroblasts Enhance Lung Adenocarcinoma Tumor Formation: Podoplanin in Fibroblast Functions for Tumor Progression

During the metastatic process, cancer cells interact with vascular adventitial fibroblasts (VAF), which are the main components of the outermost connective tissue layer of blood vessels. This activity suggests the presence of a specific tumor microenvironment in the perivascular area. The s.c. coinjection of human lung adenocarcinoma cell lines (A549, PC-14, and CRL-5807) and human VAF (hVAF) resulted in a high rate of tumor formation, compared with the coinjection of these cell lines and human lung tissue-derived fibroblasts (hLF). A cDNA microarray analysis revealed a higher expression level of podoplanin in hVAFs than in hLFs (4.7-fold). Flow cytometry analysis also showed a higher expression level of podoplanin in hVAFs (43% ± 17.5%) than in hLFs (16% ± 10.3%). Sorted podoplanin-positive hVAFs displayed enhanced tumor formation, lymph node metastasis, and lung metastasis of A549 compared to sorted podoplanin-negative hVAFs. Knockdown of podoplanin in hVAFs decreased the augmenting effect of tumor formation and in vitro colony formation. The overexpression of podoplanin in hVAFs hastened the tumor formation of A549, compared with control hVAFs. Furthermore, the analysis of small-sized human lung adenocarcinoma (n = 112) revealed that patients with podoplanin-positive cancer-associated fibroblasts had a significantly higher rate of lymph node metastasis and a high risk of recurrence. These results indicate a promotive effect of hVAFs mediated by podoplanin on cancer progression and suggest that the perivascular environment may constitute a specific niche for tumor progression.

Stromal Macrophage Expressing CD204 is Associated with Tumor Aggressiveness in Lung Adenocarcinoma

Background: Tumor tissue is composed of variable numbers of cancer cells and stromal cells, and tumor-associated macrophages are recruited into cancer-induced stroma and produce a specific microenvironment. Alternatively, activated macrophages (M2 phenotype) are known to be related to tumor progression and outcome, and CD204 has been reported to be expressed in M2 macrophages in some tumors. Methods: To investigate whether CD204-positive macrophages reflect tumor aggressiveness in adenocarcinoma of the lung, we investigated the relationships between the numbers of CD204-positive stromal macrophages and both clinicopathological features and outcome in 170 consecutive resected cases. We also examined the relationships between the numbers of CD204-positive macrophages and the expression levels of cytokines involved in the migration and differentiation of M2 macrophages. Results: The numbers of CD204-positive macrophages were significantly correlated with several prognostic factors. The log-rank test showed a significant association between the numbers of CD204-positive macrophages and a poor outcome (p = 0.0073), whereas the numbers of macrophages expressing CD68, a pan-macrophage/monocyte marker, were of marginal prognostic significance (p = 0.0789). We evaluated associations between the levels of expression of the cytokines IL-6, IL-10, IL-12a, IL-12b, M-colony-stimulating factor, IFN-gamma-., and monocyte chemoattractant protein-1 in cancer tissue and the numbers of CD204-positive macrophages. The expression levels of IL-10 and monocyte chemoattractant protein-1, which are involved in differentiation, accumulation, and migration of M2 macrophages, were significantly correlated with the numbers of CD204-positive macrophages (p = 0.031 and p = 0.031, respectively). Conclusion: These findings demonstrated that CD204-positive macrophages clearly reflect the tumor-promoting phenotype of tumor-associated macrophages in lung adenocarcinoma.

Dynamic molecular changes associated with epithelial-mesenchymal transition and subsequent mesenchymal-epithelial transition in the early phase of metastatic tumor formation

Metastatic tumor formation via vessel route begins with cancer cell extravasation from vessel lumen, migration into the connective tissue surrounding vessels, and invasion into target organ parenchyma. Epithelial–mesenchymal transition (EMT) and mesenchymal–epithelial transition (MET) have been recognized to play an important role in metastatic process, however, how and where these biological changes take place in the early phase of metastatic tumor development has never been clarified. We morphologically evaluated 34 small intrapulmonary metastases formed after cancer cell extravasation from lymphatics (lymphogenic metastasis) and 40 formed in the absence of extravasation (aerogenous metastasis) in human specimens and found that isolated or small clusters of invasive cancer cells (tumor budding) were frequently observed in lymphogenic metastasis (24/34; 71%), but were never observed within aerogenous metastasis. We immunostained 34 lymphogenic metastases for 13 molecular markers of EMT and MET and scored the immunostaining intensity of cancer cells floating in lymphatic vessels (LVs), migrating into the connective tissue surrounding vessels [bronchovascular bundle (BVB)], and growing in lung parenchyma (LP). Cancer cells within BVBs stained more weakly for E‐cadherin (p < 0.001), β‐catenin (p < 0.001), and Geminin (p < 0.001) and more strongly for MMP‐7 (p = 0.046) and Laminin‐5 γ2 (p = 0.037) than tumor cells in LVs. However, cancer cells in LP exhibited resurgent E‐cadherin (p = 0.011), β‐catenin (p < 0.001), and Geminin (p = 0.037) expression and reduced MMP‐7 (p = 0.038) and Laminin‐5 γ2 (p = 0.001) expression in comparison with cancer cells in BVBs. Our results suggested that in the early phase of metastatic tumor formation cancer cells undergo dynamic phenotypic change associated with EMT and subsequent MET.

Prognostic Significance of a Solid Component in Pulmonary Adenocarcinoma

BACKGROUND We retrospectively analyzed pulmonary adenocarcinoma patient survival in our single-institution database to evaluate the impact of solid adenocarcinoma components (SAC) on survival and to propose a method of incorporating SAC into the T classification in future staging systems. METHODS We reviewed 504 consecutive patients with surgically resected pulmonary adenocarcinoma for their clinicopathologic characteristics and prognoses, stratifying patients according to predominant adenocarcinoma subtype. We also stratified patients with an SAC-containing tumor according to the ratio of SAC in analyzing outcome. RESULTS Patients with SAC (SAC+) had significantly poorer prognoses than patients without any SAC (SAC-), irrespective of SAC ratio. Patient groups stratified by pathologic T classification up to T2b could be divided into four categories according to SAC status in decreasing order of survival: (I) T1a/SAC-; (II) T1b/SAC-; (III) T1a/SAC+, T1b/SAC+, and T2a/SAC-; and (IV) T2a/SAC+ and T2b/SAC-. CONCLUSIONS Pulmonary adenocarcinoma patients with any amount of SAC had worse prognoses than those without any SAC. The presence of SAC was an independent unfavorable prognostic factor, comparable to other pathologic findings indicating invasion. Solid adenocarcinoma component was an upstaging factor in T classification for T1 and T2a pulmonary adenocarcinomas. If SAC is present, we propose T1 and T2a tumors should be classified as T2a and T2b, respectively.

Anatomical thoracoscopic segmentectomy for lung cancer

Minimally invasive surgery for lung cancer has seen considerable progress. A segmentectomy is less invasive than a lobectomy as it preserves lung parenchyma. The preservation of pulmonary function can reduce complications. The combination of a thoracoscopic approach with a segmentectomy should be less invasive, and retrospective studies have shown that the thoracoscopic approach is safe and feasible due to the lower postoperative mortality and complication rates as compared to an open thoracotomy. The validity of a segmentectomy for ground-glass-opacity-type lung cancer has been demonstrated, and it has also been evaluated for small, predominantly solid, lung cancers. Two prospective studies of segmentectomy versus lobectomy for ≤2-cm non-small-cell lung cancer are now underway (CALGB 140503 and JCOG0802/WJTOG4607L) and should clarify the role of segmentectomy. Regarding thoracoscopic segmentectomy, few retrospective studies have reported the oncological outcome for lung cancer and there is inadequate evidence regarding the long-term oncological outcome, although the perioperative complication rate and duration of hospital stay seem to be non-inferior to those of an open approach. For preoperative simulation, three-dimensional multidetector computed tomography (3D-CT) is essential for performing an atypical thoracoscopic segmentectomy safely. Preoperative 3D-CT angiography and bronchography (3D-CTAB) enable accurate identification of the venous branches in the affected segment and the intersegmental vein. This review describes the surgical and oncological outcomes, utility of 3D-CTAB, and surgical techniques and procedure used for a thoracoscopic segmentectomy.

The clinical outcome of non-small cell lung cancer patients with adjacent lobe invasion: the optimal classification according to the status of the interlobar pleura at the invasion point

OBJECTIVES The aim of this study was to analyse the survival of non-small cell lung cancer (NSCLC) patients with adjacent lobe invasion (ALI) with emphasis on the interlobar fissure status at the tumour invasion point. METHODS We retrospectively evaluated 2097 consecutive patients with surgically resected NSCLC from July 1993 through April 2006. Of these, 90 (4.3%) patients had tumours with ALI. We divided ALIs into two types by histological examination using elastic stains: direct ALI beyond the incomplete fissure (ALI-D, n = 18) and ALI across the interlobar fissure (ALI-A, n = 72), and compared the clinicopathological features and survival. RESULTS The patients with ALI demonstrated an intermediate survival between T2a and T2b tumours (5-year overall survival: T2a, 61.0%; ALI, 59.6%; T2b, 49.2%). There were distinct survival differences between the patients with ALI-A and ALI-D (5-year overall survival: ALI-D, 85.7%; ALI-A, 52.0%; P = 0.010). The survival of patients with ALI-A was not statistically different from that of patients with T2b tumours, regardless of the tumour size (P = 0.846). The survival of the patients with ALI-D did not statistically differ from those with T1a or T1b tumours (P = 0.765 and 0.418, respectively). CONCLUSIONS Our results indicate that the interlobar fissure status affects the survival of the patients with ALI. ALI should be examined by elastic stains and only ALI-A should be classified as true ALI. We propose that ALI-A tumours with a size of ≤ 5 cm should be assigned to T2b, but ALI-D tumours do not require an adjustment of the T descriptor.

Adult neuroblastoma arising in the superior mediastinum

Adult onset neuroblastoma arising in the mediastinum, except posterior mediastinum is extremely rare. We report a case of surgically resected neuroblastoma in the superior mediastinum. A 64-year-old male was admitted to a local hospital, after an abnormal shadow had been detected on a chest radiogram on a routine medical checkup. Computed tomography (CT) examination revealed the tumor located in the superior mediastinum. Preoperatively, we suspected malignant lymphoma or lymph node metastasis from an unknown primary site. We resected the mediastinal tumor for both definitive diagnosis and local treatment. The tumor was composed of sheets of small round cells positive for CD56, NSE, chromogranin A, and vimentin, but negative for AE1/3, CK5/6, CK7, CD3, CD20, CD79a, c-kit, S-100, SMA and CD99. N-myc gene amplification was also confirmed and supported diagnosis of neuroblastoma. Chest CT seven months after surgery revealed multiple recurrences in lymph nodes.

A new application of a wound retractor for chest wall surgery.

Use of a wound retraction (WR) is useful for lung resection by video-assisted thoracic surgery via a mini-thoracotomy. We have employed a WR for chest wall surgery involving surgical rib fixation in a patient with rib fractures, and obtained successful results in terms of a good surgical view and lack of postoperative wound infection. On the basis of our experience, we consider that a WR is useful even for chest wall surgery.

STXBP4 Drives Tumor Growth and Is Associated with Poor Prognosis through PDGF Receptor Signaling in Lung Squamous Cell Carcinoma

Purpose: Expression of the ΔN isoform of p63 (ΔNp63) is a diagnostic marker highly specific for lung squamous cell carcinoma (SCC). We previously found that Syntaxin Binding Protein 4 (STXBP4) regulates ΔNp63 ubiquitination, suggesting that STXBP4 may also be an SCC biomarker. To address this issue, we investigated the role of STXBP4 expression in SCC biology and the impact of STXBP4 expression on SCC prognosis. Experimental Design: We carried out a clinicopathologic analysis of STXBP4 expression in 87 lung SCC patients. Whole transcriptome analysis using RNA-seq was performed in STXBP4-positive and STXBP4-negative tumors of lung SCC. Soft-agar assay and xenograft assay were performed using overexpressing or knockdown SCC cells. Results: Significantly higher levels of STXBP4 expression were correlated with accumulations of ΔNp63 in clinical lung SCC specimens (Spearman rank correlation ρ = 0.219). Notably, STXBP4-positive tumors correlated with three important clinical parameters: T factor (P < 0.001), disease stage (P = 0.030), and pleural involvement (P = 0.028). Whole transcriptome sequencing followed by pathway analysis indicated that STXBP4 is involved in functional gene networks that regulate cell growth, proliferation, cell death, and survival in cancer. Platelet-derived growth factor receptor alpha (PDGFRα) was a key downstream mediator of STXBP4 function. In line with this, shRNA mediated STXBP4 and PDGFRA knockdown suppressed tumor growth in soft-agar and xenograft assays. Conclusions: STXBP4 plays a crucial role in driving SCC growth and is an independent prognostic factor for predicting worse outcome in lung SCC. These data suggest that STXBP4 is a relevant therapeutic target for patients with lung SCC. Clin Cancer Res; 23(13); 3442–52. ©2017 AACR.

Analysis of variation in bronchovascular pattern of the right middle and lower lobes of the lung using three-dimensional CT angiography and bronchography

ObjectivesGeneral thoracic surgeons must be familiar with anatomical variation in the pulmonary vessels and bronchi. Here, we analyzed the bronchovascular pattern of the right middle lobe (RML) and right lower lobe (RLL) of the lung using three-dimensional CT angiography and bronchography (3DCTAB).MethodsWe reviewed the anatomical patterns of the pulmonary vessels and bronchi in 270 patients using 3DCTAB images.ResultsThe branching patterns of vessels and bronchi of RML and S6 were classified according to the number of stems. The single-stem type was the most common, except in the artery of the RML, for which the two-stem type was the most common. The artery and bronchus of S*, which is an independent segment between S6 and S10, were observed in 20.4% of cases. The branching pattern of A7 (B7) was classified into four types. The A7a (B7a) type was observed in 74.8% of cases, and was the most common. The branching pattern of the artery and bronchus of S8−10 was classified into five and three types, respectively. The A8 and A9 + A10 type, and the B8 and B9 + B10 type, were observed in 68.1 and 80.4% of cases, respectively, and were the most common types. The branching pattern of V8−10 was more complex than that of A8−10 and B8−10.ConclusionWe explored the bronchovascular patterns of RML and RLL and their frequencies using a large number of 3DCTAB images. Our data can be used by thoracic surgeons to perform safe and precise lung resections.