Distinct transcriptional programs of SOX2 in different types of small cell lung cancers.

SOX2 is recognized as an oncogene in human small cell lung cancer (SCLC), which is an aggressive neuroendocrine (NE) tumor. However, the role of SOX2 in SCLC is not completely understood, and strategies to selectively target SOX2 in SCLC cells remain elusive. Here, we show, using next-generation sequencing, that SOX2 expressed in the ASCL1-high SCLC (SCLC-A) subtype cell line is dependent on ASCL1, which is a lineage-specific transcriptional factor, and is involved in NE differentiation and tumorigenesis. ASCL1 recruits SOX2, which promotes INSM1 and WNT11 expression. Immunohistochemical studies revealed that SCLC tissue samples expressed SOX2, ASCL1, and INSM1 in 18 out of the 30 cases (60%). Contrary to the ASCL1-SOX2 signaling axis controlling SCLC biology in the SCLC-A subtype, SOX2 targets distinct genes such as those related to the Hippo pathway in the ASCL1-negative, YAP1-high SCLC (SCLC-Y) subtype. Although SOX2 knockdown experiments suppressed NE differentiation and cell proliferation in the SCLC-A subtype, they did not sufficiently impair the growth of the SCLC-Y subtype cell lines in vitro and ex vivo. The present results support the importance of the ASCL1-SOX2 axis as a main subtype of SCLC, and suggest the therapeutic potential of targeting the ASCL1-SOX2 axis.

Rabbit VX2 lung tumor models can form early nodal metastases.

BACKGROUND: The rabbit squamous cell cancer line, VX2, has been used to generate various tumor models in rabbits. It is notable for its ability to generate nodal metastases. However, the timing and extent of nodal metastases vary by primary inoculation site and methodology. The development of metastases specifically in lung cancer models has not been well-described. We sought to characterize the generation of nodal metastases in rabbit transbronchial VX2 lung tumor models. METHODS: Rabbit VX2 lung tumor models were created in the right lung via transbronchial injection and serially imaged by computed tomography. Rabbits (n = 15) were sacrificed from between 5 and 24 days post-inoculation for collection of the ipsilateral and contralateral paratracheal lymph nodes. These underwent histopathological evaluation for metastases using hematoxylin and eosin as well as cytokeratin AE1/AE3 immunohistochemical staining. RESULTS: Nodal metastases were detectable as early as 1 week after inoculation but were more prevalent with longer inoculation; all rabbits at > 2 weeks post-inoculation had nodal metastases. Contralateral metastases were in general seen later than ipsilateral metastases. Lymph node volume did not predict the likelihood of nodal metastases (p = 0.4 and p = 0.07 for ipsilateral and contralateral nodal metastases, respectively), but primary tumor volume was significantly associated with the likelihood of nodal metastases (p = 0.001 and p = 0.005 for ipsilateral and contralateral nodal metastases, respectively). Ipsilateral metastases were detectable at a tumor diameter of 1 cm; contralateral metastases were more variable but in general required a tumor diameter of 2 cm. CONCLUSIONS: Rabbit transbronchial VX2 lung tumor models generate nodal metastases relatively early after inoculation. These results suggest such models may be valuable tools in the investigation of novel therapeutic modalities relevant for the treatment of both early-stage and locally advanced lung cancer.

Insulinoma-associated protein 1 (INSM1) is a useful marker for pancreatic neuroendocrine tumor.

Insulinoma-associated protein 1 (INSM1) is an important biomarker of Achaete-scute homolog-like 1-driven pathways. For diagnosis of pancreatic neuroendocrine tumors (PanNET), chromogranin A (CGA), synaptophysin (SYP), and neural cell adhesion molecule (NCAM) were also considered as potential biomarkers. However, it is often difficult to diagnose it immunohistochemically. Hence, we examined the expression pattern of INSM1 in pancreatic solid tumors. We detected INSM1, CGA, SYP, and NCAM immunohistochemically, in 27 cases of NET [pure type: 25 cases, mixed adenoneuroendocrine carcinoma (MANEC): 2 cases]. We included 5 cases of solid-pseudopapillary neoplasm (SPN), 7 cases of acinar cell carcinoma (ACC), and 15 cases of pancreatic ductal adenocarcinoma (PDAC) as the control group. Nuclear expression of INSM1 was found in all PanNET pure type cases. However, expression of INSM1 was negative in PDAC, ACC, and SPN in all cases, whereas faint expression was seen in the cytoplasm from SPN. MANEC comprises of two components: neuroendocrine carcinoma and adenocarcinoma components. The NET component was positive for INSM1 expression, whereas the PDAC component does not express INSM1, which aids in distinguishing these components. Our results suggest that INSM1 is a useful immunohistochemical marker for diagnosing pancreatic neuroendocrine tumor.

Correlation between histone acetylation and expression of Notch1 in human lung carcinoma and its possible role in combined small-cell lung carcinoma.

Combined small-cell lung carcinoma (cSCLC) is composed of small-cell lung carcinoma (SCLC) admixed with non-small-cell lung carcinoma (NSCLC). Evaluating the molecular differences between SCLC and NSCLC could lead to a better understanding of the pathogenesis of such neoplasms. Therefore, in this study, we investigated the correlation between histone acetylation and Notch1 expression in lung carcinoma. Using chromatin immunoprecipitation (ChIP) assay, we measured the level of acetylated histone H3 around the promoter region of Notch1 in SCLC and NSCLC cells. We then treated SCLC cells with trichostatin A (TSA) and characterized the level of histone H3 acetylation at Notch1. In addition, TSA-treated cells were injected into immune-compromised mice, for analysis of the ex vivo tumor xenograft phenotype. The level of acetylated histone H3 surrounding the Notch1 promoter was lower in lung cancer cells not expressing Notch1. Tumors originated from TSA-treated SCLC cells occasionally formed an epithelial-like glandular arrangement of cells; with Notch1 expression and decreased expression of neuroendocrine (NE) markers. Histone deacetylation around the promoter region of Notch1 inhibits Notch1 protein expression in SCLC and the restoration of Notch1 expression in SCLC leads to the concurrent appearance of epithelial-like areas within the SCLC, which could provide a possible mechanism for histogenesis of cSCLC.

Insulinoma-Associated Protein 1 Is a Crucial Regulator of Neuroendocrine Differentiation in Lung Cancer.

Insulinoma-associated protein 1 (INSM1) is expressed exclusively in embryonic developing neuroendocrine (NE) tissues. INSM1 gene expression is specific for small-cell lung cancer (SCLC), along with achaete-scute homolog-like 1 (ASCL1) and several NE molecules, such as chromogranin A, synaptophysin, and neural cell adhesion molecule 1. However, the underlying biological role of INSM1 in lung cancer remains largely unknown. We first showed that surgically resected SCLC samples specifically expressed INSM1. Forced expression of the INSM1 gene in adenocarcinoma cell lines (H358 and H1975) induced the expression of ASCL1, brain-2 (BRN2), chromogranin A, synaptophysin, and neural cell adhesion molecule 1; in contrast, knockdown of the INSM1 gene by siRNA in SCLC (H69 and H889) decreased their expression. However, forced/knockdown expression of ASCL1 and BRN2 did not affect INSM1 expression. A chromatin immunoprecipitation study revealed that INSM1 bound to the promoter region of the ASCL1 gene. A xenotransplantation assay using tet-on INSM1 gene-transfected adenocarcinoma cell lines demonstrated that INSM1 induced NE differentiation and growth inhibition. Furthermore, we found that INSM1 was not expressed in non-small-cell lung cancer and some SCLC cell lines expressing Notch1-Hes1. By forced/knockdown expression of Notch1 or Hes1 genes, we revealed that Notch1-Hes1 signaling suppressed INSM1, as well as ASCL1 and BRN2. INSM1, expressed exclusively in SCLC, is a crucial regulator of NE differentiation in SCLCs, and is regulated by the Notch1-Hes1 signaling pathway.

Novel approach to pleurodesis with 50 % glucose for air leakage after lung resection or pneumothorax.

PURPOSE: Pleurodesis is performed in patients demonstrating air leakage after lung resection and in those with pneumothorax who must avoid surgery. However, there have so far been very few reports of pleurodesis with 50 % glucose. We herein examined the feasibility and effectiveness of this novel pleurodesis technique. METHODS: Thirty-five patients after lung resection and 11 pneumothorax patients without surgery were treated with pleurodesis using 50 % glucose. Approximately, 200 mL of 50 % glucose solution was injected into the pleural space and repeated until the air leakage stopped. Cases in which the air leakage did not stop after three injections were considered to be unsuccessful and subsequently treated with conventional pleurodesis using OK-432. RESULTS: Thirty-nine patients were successfully treated with 50 % glucose, although 7 patients required further treatment with OK-432. The unsuccessful group had some pulmonary comorbidities (P < 0.001), and the pleural effusion volume after pleurodesis was less than that in the successful group (P < 0.001). Although the air leakage did not stop in unsuccessful patients, the amount of air leakage markedly decreased. A temporary elevation of the blood sugar level was observed in 20 patients, but no other side effects had appeared. CONCLUSIONS: Pleurodesis with 50 % glucose is an easy, safe, and effective treatment modality. It is therefore considered to be a useful alternative method for pleurodesis.

Tension Pneumomediastinum in Anti-MDA5 Antibody-positive Dermatomyositis-associated Interstitial Lung Disease: A Case Report and Literature Review.

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (DM)-associated interstitial lung disease (ILD) can sometimes be complicated by pneumomediastinum, although tension pneumomediastinum is extremely rare. We herein report a case of anti-MDA5 antibody-positive DM-ILD that worsened subcutaneous and mediastinal emphysema during treatment. Hypotension and worsening respiratory failure were observed on day 20 of treatment. Mediastinal drainage under video-assisted thoracoscopic surgery promptly improved the patient's circulatory and respiratory status. Tension pneumomediastinum is a rare complication; however, it is a serious condition that may lead to hypotension or cardiac arrest and requires a prompt diagnosis and treatment.

NUF2 Expression in Cancer Tissues and Lymph Nodes Suggests Post-Surgery Recurrence of Non-Small Cell Lung Cancer.

In non-small cell lung cancer (NSCLC) cases, detecting potential lymph node metastases is essential to determine the indications for sublobar resection or adjuvant therapy. NUF2 is a tumor-specific antigen that is highly expressed in lung cancer tissues. However, the significance of analyzing NUF2 expression in dissected lymph nodes has not yet been studied. Thus, we investigated the association between NUF2 expression in lung cancer tissues and dissected lymph nodes and early recurrence of NSCLC to determine its usefulness as a marker of lymph node micrometastasis. This retrospective study quantified NUF2 expression in the cancer tissues of 88 patients with NSCLC who underwent complete resection using real-time polymerase chain reaction and investigated its relationship with clinicopathological features and prognosis. We also quantified NUF2 RNA expression in mediastinal lymph nodes from 255 patients with pN0 NSCLC who underwent complete resection with lymph node dissection and analyzed its association with prognosis. NUF2 expression in primary tumors was correlated with lymph node metastasis and unfavorable outcomes in terms of poor recurrence-free and cancer-specific survival. In N0 NSCLC cases, high NUF2 expression in mediastinal lymph nodes indicated poor prognosis, especially in lymph node recurrence. NUF2 emerges as a promising marker for predicting lymph node metastatic recurrence, offering potential utility in guiding post-surgical adjuvant therapy for lung cancer or assisting in intraoperative decisions for sublobar resection.

Negative impact of ratio of the microvascular area to tumor area on the response to EGFR-TKI in non-small cell lung cancer with an EGFR mutation.

Background: The clinical impact of tumor microvessels on the efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in EGFR mutation-positive non-small cell lung cancer (NSCLC) is unclear. Thus, the aim of this study was to investigate whether a tumor microenvironment, abundant in microvessels, affects EGFR-TKI efficacy in patients with NSCLC and EGFR mutations. Methods: We retrospectively studied the data of 40 post-operative patients with recurrent NSCLC and EGFR mutations who received EGFR-TKIs as a first-line treatment at Kumamoto University Hospital from January 2010 to February 2021. Tumor sections were retrieved from the tissue registry and analyzed for CD34-positive microvessels using immunohistochemical techniques. The ratio of microvascular area to tumor area (RMV), which is the CD34-positive microvascular area compared to the total tumor area, was measured using StrataQuest. The predictive value of RMV on treatment outcome, assessed via progression-free survival (PFS), was evaluated using a multivariate Cox proportional hazard model. Results: The median PFS in the high RMV group (≥0.058) was significantly shorter than that in the low RMV group [<0.058; 296 days, 95% confidence interval (CI): 217-374 vs. 918 days, 95% CI: 279-1,556, P=0.002]. Multivariate analysis revealed that high RMV was an independent negative predictor of PFS (hazard ratio, 3.21; 95% CI: 1.18-8.76, P=0.022). Conclusions: High RMV may critically affect EGFR-TKI resistance in patients with NSCLC and EGFR mutations.

Impact of central nervous system metastasis after complete resection of lung adenocarcinomas harboring common EGFR mutation - A real-world database study in Japan: The CReGYT-01 EGFR study.

OBJECTIVES: To clarify the impact of central nervous system (CNS) metastasis on performance status (PS) at relapse, on subsequent treatment(s), and on survival of patients with lung adenocarcinoma harboring common epidermal growth factor receptor (EGFR) mutation. METHODS: We conducted the multicenter real-world database study for patients with radical resections for lung adenocarcinomas between 2015 and 2018 at 21 centers in Japan. EGFR mutational status was examined at each center. RESULTS: Of 4181 patients enrolled, 1431 underwent complete anatomical resection for lung adenocarcinoma harboring common EGFR mutations. Three-hundred-and-twenty patients experienced disease relapse, and 78 (24%) had CNS metastasis. CNS metastasis was significantly more frequent in patients with conventional adjuvant chemotherapy than those without (30% vs. 20%, P = 0.036). Adjuvant chemotherapy did not significantly improve relapse-free survival at any pathological stage (adjusted hazard ratio for stage IA2-3, IB, and II-III was 1.363, 1.287, and 1.004, respectively). CNS metastasis did not affect PS at relapse. Subsequent treatment, mainly consisting of EGFR-tyrosine kinase inhibitors (TKIs), could be equally given in patients with or without CNS metastasis (96% vs. 94%). Overall survival after relapse was equivalent between patients with and without CNS metastasis. CONCLUSION: The efficacy of conventional adjuvant chemotherapy may be limited in patients with lung adenocarcinoma harboring EGFR mutations. CNS metastasis is likely to be found in practice before deterioration in PS, and may have little negative impact on compliance with subsequent EGFR-TKIs and survival after relapse. In this era of adjuvant TKI therapy, further prospective observational studies are desirable to elucidate the optimal management of CNS metastasis.

Heterogeneous expression and role of receptor tyrosine kinase-like orphan receptor 2 (ROR2) in small cell lung cancer.

The present study investigated the expression and role of ROR2 in small cell lung cancer (SCLC). To examine the expression of ROR2, 27 surgically resected SCLC tissue samples were immunostained for ROR2. Sixteen tissue samples were positive and some showed intratumor heterogeneity in staining intensity. The heterogeneity of ROR2 expression was also observed in tumor tissues from a PDX model of SCLC, in which there were cells with high ROR2 expression (ROR2high cells) and without its expression (ROR2low cells). These cells were subjected to a RNA sequence analysis. GSEA was performed and the results obtained revealed the enrichment of molecules such as G2M checkpoint, mitotic spindle, and E2F targets in ROR2high cells. The rate of EdU incorporation was significantly higher in ROR2high cells than ROR2low cells from the PDX model and the SCLC cell lines. Cell proliferation was suppressed in ROR2 KO SBC3 cells in vitro and in vivo. Comparisons of down-regulated differentially expressed genes in ROR2 KO SBC3 cells with up-regulated DEG in ROR2high cells from the PDX model revealed 135 common genes. After a Metascape analysis of these genes, we focused on Aurora kinases. In SCLC cell lines, the knockdown of ROR2 suppressed Aurora kinases. Therefore, ROR2 appears to regulate the cell cycle through Aurora kinases. The present results reveal a role for ROR2 in SCLC and afford a candidate system (ROR2-Aurora kinase) accompanying tumor heterogeneity in SCLC.

Development of a minimally invasive pulmonary porcine embolism model via endobronchial ultrasound.

Background: Current massive pulmonary embolism (PE) animal models use central venous access to deliver blood clots, which have features of random clot distribution and potentially fatal hemodynamic compromise. A clinically relevant preclinical model for generating pulmonary emboli in a more controlled fashion would be of value for a variety of research studies, including initial evaluation of novel therapeutic approaches. Endobronchial ultrasound-guided transbronchial needle injection (EBUS-TBNI) is a newly established approach for peri-tracheal/bronchial targets. The purpose of the present work was to establish a minimally invasive PE model in swine via a transbronchial approach. Methods: In anesthetized Yorkshire pigs, a 21-G EBUS-guided transbronchial needle aspiration (EBUS-TBNA) needle was introduced into the pulmonary artery under EBUS guidance. Autologous blood clots were administered into the right and left lower pulmonary arteries sequentially (PE1 and PE2, respectively). Hemodynamic and biochemical responses were evaluated. Results: Ten pigs were evaluated; all 20 blood clots (6.3±1.9 mL) were successfully injected. After injection, mean pulmonary artery pressure (mPAP; mmHg) increased (baseline: 16.6±5.6 vs. PE1: 24.5±7.6, P<0.0001 vs. PE2: 26.9±6.7, P<0.0001), and a positive correlation was observed between clot volume and change in mPAP (PE1: r=0.69, P=0.025; PE1 + PE2: r=0.60, P=0.063). Mean arterial pressure (MAP; mmHg) (baseline: 57.5±5.1 vs. PE1: 59.0±9.1, P=0.918 vs. PE2: 60.9±9.6, P=0.664) remained stable. No complications were observed. Conclusions: EBUS allows minimally invasive, precise, and reliable generation of pulmonary emboli in pigs. This model may serve as an important tool for new PE-related diagnostic and therapeutic research.

Clinical impact of SUVmax of interstitial lesions in lung cancer patients with interstitial lung disease who underwent pulmonary resection.

Background: Acute exacerbation of interstitial lung disease often causes fatal respiratory deterioration in lung cancer patients with interstitial lung disease. Here, we examined whether the maximum standardized uptake value of a contralateral interstitial lesion was a predictive factor of acute exacerbation of interstitial lung disease within 30 days postoperatively in lung cancer patients with interstitial lung disease who underwent pulmonary resection. Methods: Overall, 117 consecutive lung cancer patients with interstitial lung disease who underwent pulmonary resection between August 2010 and April 2019 at the Kumamoto University Hospital were retrospectively analysed for the association between the maximum standardized uptake value of the contralateral interstitial lesions and interstitial lung disease parameters. Results: The median maximum standardized uptake value of contralateral interstitial lesions was 1.61, which was regarded as the cut-off point predictive of the incidence of acute exacerbation of interstitial lung disease. Eight patients developed postoperative acute exacerbation of interstitial lung disease. There was no significant association between the maximum standardized uptake value of the contralateral interstitial lesions and postoperative acute exacerbation of interstitial lung disease. The maximum standardized uptake value was weakly but significantly associated with lactate dehydrogenase levels (r=0.211, P=0.022), Krebs von den Lungen-6 (r=0.208, P=0.028), and % diffusing capacity for carbon monoxide (r=-0.290, P=0.002). Moreover, seven patients developed acute exacerbation of the interstitial lung disease during the clinical course after 30 postoperative days, and the incidence rate of acute exacerbation of interstitial lung disease was significantly higher in the high maximum standardized uptake value group (≥1.61) than in the low maximum standardised uptake value group (<1.61) (12.7% vs. 0%, P=0.002, Gray's test). Conclusions: Maximum standardized uptake value was not a predictor of postoperative acute exacerbation of interstitial lung disease in lung cancer patients with interstitial lung disease after pulmonary resection, but could be a predictive tool of an association with interstitial lung disease severity and activity markers.

Pulmonary Neuroendocrine Cells and Small Cell Lung Carcinoma: Immunohistochemical Study Focusing on Mechanisms of Neuroendocrine Differentiation.

Neuroendocrine (NE) differentiation has been histochemically detected in normal and cancer tissues and cells. Immunohistochemical analyses have provided a more detailed understanding of NE biology and pathology. Pulmonary NE cells are a rare lung epithelial type, and small cell carcinoma of the lung (SCLC) is a high-grade NE tumor. Pulmonary NE and SCLC cells share common mechanisms for NE differentiation. Neural or NE cell lineage-specific transcription factors, such as achaete-scute homologue 1 (Ascl1) and insulinoma-associated protein 1 (INSM1), are crucial for the development of pulmonary NE cells, and NE differentiation is influenced by the balance between Ascl1 and the suppressive neural transcription factor, hairy-enhancer of split 1, a representative target molecule of the Notch signaling pathway. In this review, we discuss the importance of Ascl1 and INSM1 in identifying pulmonary NE and SCLC cells and introduce Ascl1-related molecules detected by comparative RNA-sequence analyses. The molecular classification of SCLC based on the expression of lineage-specific transcription or co-transcription factors, including ASCL1, NEUROD1, POU2F3, and YAP1, was recently proposed. We attempted to characterize these 4 SCLC subtypes using integrated immunohistochemical studies, which will provide insights into the molecular characteristics of these subtypes and clarify the inter- and intratumor heterogeneities of SCLC.

Specific techniques for right sleeve lower lobectomy: four case reports.

BACKGROUND: Right sleeve lower lobectomy is rarely performed because pulmonary function of the middle lobe is not spared to the extent of the other lobes and achieving a proper bronchial anastomosis is technically more difficult than other sleeve lobectomies. CASE PRESENTATION: We performed four right sleeve lower lobectomies and had good clinical outcomes using specific technical options, such as telescope anastomosing, pericardiotomy, interlobar dissection between the upper and middle lobes, and angioplasty of the lower pulmonary artery, if needed. CONCLUSIONS: The cases presented herein demonstrated that a right sleeve lower lobectomy is one option by which to preserve the middle lobe using specific techniques and is thus recommended in select patients.

Simultaneous surgical resection of cardiac myxoma and atypical thymic carcinoid: a case report.

BACKGROUND: Cardiac myxoma is the most common type of primary cardiac tumor, and thymic carcinoid is a rare neuroendocrine tumor. No previous reports have described surgical management of concomitant occurrence of these neoplasms. We report a case of simultaneous surgical resection in a patient with coexisting cardiac myxoma and atypical thymic carcinoid. CASE PRESENTATION: A 44-year-old Japanese woman underwent chest roentgenography revealing an abnormality in the mediastinum. Computed tomography revealed a 100 mm mass in the anterior mediastinum and also a 30 mm mass in the left atrium. The mediastinal tumor was diagnosed as atypical carcinoid by biopsy. Having completed resection of atypical thymic carcinoid, cardiac mass was successfully resected with careful consideration of minimizing operation time and optimizing patient safety and oncological treatment. The histopathological diagnosis of the cardiac mass was myxoma. No adjuvant chemotherapy was administered, and no recurrence was seen as of the 45 month follow-up. CONCLUSIONS: The simultaneous surgery of cardiac myxoma and atypical thymic carcinoid was feasible and effective. To the best of our knowledge, this is the first case report to describe one-stage treatment of these neoplasms.

Thrombolysis of Pulmonary Emboli via Endobronchial Ultrasound-Guided Transbronchial Needle Injection.

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle injection (EBUS-TBNI) is a novel technique for treating peribronchial targets. The aim of this study was to evaluate preliminary feasibility of thrombolysis of pulmonary emboli via EBUS-TBNI. METHODS: Yorkshire pigs (30-48 kg) were anesthetized and mechanically ventilated. Pre-formed autologous clots were injected sequentially into bilateral lower pulmonary arteries in bilateral models (PE1 and PE2, respectively) or into 1 side in unilateral models using a 21-gauge EBUS-TBNA needle under EBUS guidance. In the bilateral model, 2 hours after clot injection either 25 mL of tissue-plasminogen activator (t-PA; 1mg/mL) or distilled water were administered into each embolus via 25-gauge EBUS-TBNA needle. In the unilateral model, 25 mg t-PA was administered intravenously. Hemodynamic parameters were monitored continuously, and clot dissolved volume was evaluated by EBUS 30 minutes post-treatment administration. RESULTS: All clots (6.1 ± 1.7 mL) were successfully injected as documented by EBUS Doppler imaging. Clot injection in the bilateral model (n = 6) increased pulmonary arterial pressure (mm Hg: Baseline 19.2 ± 5.9 vs PE1: 26.7 ± 9.1, P = .005 vs PE2 29.9 ± 7.1, P = .0007). After t-PA TBNI in the bilateral model (n = 6), pulmonary arterial pressure at 30 minutes post-injection showed improvement (mm Hg: PE2 29.9 ± 7.1 vs post-t-PA 24.4 ± 3.9, P = .0283). Treatment with t-PA TBNI demonstrated superior clot dissolution at 30 minutes post-treatment (dissolved mm3: t-PA TBNI 625.4 ± 156.6 vs t-PA intravenously: 181.6 ± 94.3, P = .0003 vs distilled water TBNI 42.5 ± 33.0, P < .0001). There were no complications. CONCLUSIONS: EBUS-guided transbronchial thrombolysis may be a feasible approach for treating central pulmonary emboli.

Integrated Immunohistochemical Study on Small-Cell Carcinoma of the Lung Focusing on Transcription and Co-Transcription Factors.

Small-cell lung cancer (SCLC) is an aggressive malignant cancer that is classified into four subtypes based on the expression of the following key transcription and co-transcription factors: ASCL1, NEUROD1, YAP1, and POU2F3. The protein expression levels of these key molecules may be important for the formation of SCLC characteristics in a molecular subtype-specific manner. We expect that immunohistochemistry (IHC) of these molecules may facilitate the diagnosis of the specific SCLC molecular subtype and aid in the appropriate selection of individualized treatments. We attempted IHC of the four key factors and 26 candidate SCLC target molecules selected from the gene expression omnibus datasets of 47 SCLC samples, which were grouped based on positive or negative results for the four key molecules. We examined differences in the expression levels of the candidate targets and key molecules. ASCL1 showed the highest positive rate in SCLC samples, and significant differences were observed in the expression levels of some target molecules between the ASCL1-positive and ASCL1-negative groups. Furthermore, the four key molecules were coordinately and simultaneously expressed in SCLC cells. An IHC study of ASCL1-positive samples showed many candidate SCLC target molecules, and IHC could become an essential method for determining SCLC molecular subtypes.

Photoacoustic imaging to localize indeterminate pulmonary nodules: A preclinical study.

PURPOSE: Diagnosis and resection of indeterminate pulmonary nodules (IPNs) is a growing challenge with increased utilization of chest computed tomography. Photoacoustic (PA) -guided surgical resection with local injection of indocyanine green (ICG) may have utility for IPNs that are suspicious for lung cancer. This preclinical study explores the potential of PA imaging (PAI) to detect ICG-labeled tumors. MATERIALS AND METHODS: ICG uptake by H460 lung cancer cells was evaluated in vitro. A phantom study was performed to analyze PA signal intensity according to ICG concentration and tissue thickness/depth using chicken breast. PA signals were measured up to 48 hours after injection of ICG (mixed with 5% agar) into healthy subcutaneous tissue, subcutaneous H460 tumors and right healthy lung in nude mice. RESULTS: Intracellular ICG fluorescence was detected in H460 cells co-incubated with ICG in vitro. The concentration dependence of the PA signal was logarithmic, and PA signal decline was exponential with increasing tissue depth. The PA signal of 2 mg/mL ICG was still detectable at a depth of 22 mm in chicken breast. The PA signal from ICG mixed with agar was detectable 48 hours post injection into subcutaneous tissue and subcutaneous H460 tumors in nude mice. Similar features of PA signals from ICG-agar in mice lung were obtained. CONCLUSION: The results from this preclinical study suggests that PAI of injected ICG-agar may be beneficial for identifying deeply located tumors. These features may be valuable for IPNs.

Endobronchial Ultrasound-Guided Radiofrequency Ablation of Lung Tumors and Mediastinal Lymph Nodes: A Preclinical Study in Animal Lung Tumor and Mediastinal Adenopathy Models.

Radiofrequency ablation (RFA) can be a therapeutic option in medically inoperable lung cancer patients. In this study, we evaluated a prototype bipolar RFA device applicator that can be deployed from a standard endobronchial ultrasound (EBUS) bronchoscope to determine feasibility and histopathological analysis in animal models. Rabbit lung cancers were created by transbronchial injection of VX2 rabbit cancer cells. Once the tumors were developed, they were ablated transpleurally, under EBUS guidance using the prototype RFA device. The animals were then sacrificed for specimen resection. Pig inflammatory lung pseudo-tumors and lymphadenopathy were created by transbronchial injection of a talc paste and ablated transbronchially under EBUS guidance. Pigs were evaluated at 5 days, 2 weeks, and 4 weeks following ablation by bronchoscopy and cone beam computed tomography before necropsy. Nicotinamide adenine dinucleotide hydrogen diaphorase staining was employed to measure the ablation area. Twenty-four VX2 rabbit tumors were ablated. The total ablated area ranged from 0.6 to 3.0 cm2 (mean: 1.8 cm2), corresponding to a total energy range of 1 to 6 kJ. Six pig lung pseudo-tumors and 5 mediastinal lymph nodes were ablated. Adjacent airway ulceration was observed in 3 ablations of lymph nodes. These airway complications resolved within 4 weeks of RFA without any treatment. There was no hemoptysis, air embolism, respiratory distress, or other serious complication noted. In these 2 animal models, we provide evidence that EBUS-guided bipolar RFA is feasible and histopathology shows that can ablate lung tumors and mediastinal lymph nodes under real-time ultrasound guidance.