CD90+CD146+ identifies a pulmonary mesenchymal cell subtype with both immune modulatory and perivascular-like function in postnatal human lung.

Our understanding of mesenchymal cell subsets and their function in human lung affected by aging and in certain disease settings remains poorly described. We use a combination of flow cytometry, prospective cell-sorting strategies, confocal imaging, and modeling of microvessel formation using advanced microfluidic chip technology to characterize mesenchymal cell subtypes in human postnatal and adult lung. Tissue was obtained from patients undergoing elective surgery for congenital pulmonary airway malformations (CPAM) and other airway abnormalities including chronic obstructive pulmonary disease (COPD). In microscopically normal postnatal human lung, there was a fivefold higher mesenchymal compared with epithelial (EpCAM+) fraction, which diminished with age. The mesenchymal fraction composed of CD90+ and CD90+CD73+ cells was enriched in CXCL12 and platelet-derived growth factor receptor-α (PDGFRα) and located in close proximity to EpCAM+ cells in the alveolar region. Surprisingly, alveolar organoids generated from EpCAM+ cells supported by CD90+ subset were immature and displayed dysplastic features. In congenital lung lesions, cystic air spaces and dysplastic alveolar regions were marked with an underlying thick interstitium composed of CD90+ and CD90+PDGFRα+ cells. In postnatal lung, a subset of CD90+ cells coexpresses the pericyte marker CD146 and supports self-assembly of perfusable microvessels. CD90+CD146+ cells from COPD patients fail to support microvessel formation due to fibrinolysis. Targeting the plasmin-plasminogen system during microvessel self-assembly prevented fibrin gel degradation, but microvessels were narrower and excessive contraction blocked perfusion. These data provide important new information regarding the immunophenotypic identity of key mesenchymal lineages and their change in a diverse setting of congenital lung lesions and COPD.

Increased sensitivity to apoptosis upon endoplasmic reticulum stress-induced activation of the unfolded protein response in chemotherapy-resistant malignant pleural mesothelioma.

BACKGROUND: Standard treatment for advanced malignant pleural mesothelioma (MPM) is a cisplatin/pemetrexed (MTA) regimen; however, this is confronted by drug resistance. Proteotoxic stress in the endoplasmic reticulum (ER) is a hallmark of cancer and some rely on this stress signalling in response to cytotoxic chemotherapeutics. We hypothesise that ER stress and the adaptive unfolded protein response (UPR) play a role in chemotherapy resistance of MPM. METHODS: In vitro three-dimensional (3D) and ex vivo organotypic culture were used to enrich a chemotherapy-resistant population and recapitulate an in vivo MPM microenvironment, respectively. Markers of ER stress, the UPR and apoptosis were assessed at mRNA and protein levels. Cell viability was determined based on acid phosphatase activity. RESULTS: MPM cells with de novo and/or acquired chemotherapy resistance displayed low ER stress, which rendered the cells hypersensitive to agents that induce ER stress and alter the UPR. Bortezomib, an FDA-approved proteasome inhibitor, selectively impairs chemotherapy-resistant MPM cells by activating the PERK/eIF2α/ATF4-mediated UPR and augmenting apoptosis. CONCLUSIONS: We provide the first evidence for ER stress and the adaptive UPR signalling in chemotherapy resistance of MPM, which suggests that perturbation of the UPR by altering ER stress is a novel strategy to treat chemotherapy-refractory MPM.

First Rib Resection for Thoracic Outlet Syndrome: The Robotic Approach.

OBJECTIVE: First rib resection is a well-recognized treatment option for thoracic outlet syndrome (TOS). In case of a vascular insufficiency that can be provoked and/or progressive neurologic symptoms without response to conservative treatment, surgical decompression of the space between the clavicle and the first rib is indicated. The aim of this paper is to present our experience with a new minimally invasive robotic approach using the da Vinci Surgical System®. METHODS: Between January 2015 and October 2017, eight consecutive first rib resections in seven patients were performed at our institution. Four patients presented with neurologic (one bilateral), and three patients with vascular (venous) impairment. In all cases, a transthoracic robotic-assisted approach was used. The first rib was removed using a 3-port robotic approach with an additional 2-cm axillary incision in the first six patients. The latest resection was performed through only three thoracic ports. RESULTS: Median operative time was 108 min, and the median hospital stay was 2 days. Postoperative courses were uneventful in all patients. Clinical follow-up examinations showed relief of symptoms in all nonspecific TOS patients, and duplex ultrasonography confirmed complete vein patency in the remaining patients 3 months after surgery. CONCLUSIONS: While there are limitations in conventional transaxillary, subclavicular and supraclavicular approaches in the first rib resection, the robotic method is not only less invasive but also allows better exposure and visualization of the first rib. Furthermore, the technique takes advantage of the benefits of the da Vinci Surgical System® in terms of 3D visualization and improved instrument maneuverability. Our early experience clearly demonstrates these advantages, which are also supported by the very good outcomes.

Xiphoidectomy for Intractable Xiphodynia.

BACKGROUND: Xiphodynia is a rare condition with hardly any data published regarding xiphoidectomy as a valid treatment option for intractable disease. It is necessary to bear this syndrome in mind after having filtered out other differential diagnoses. METHODS: Between 2003 and 2015, 11 patients underwent xiphoidectomy for intractable xiphodynia at our institution. Patients' charts were reviewed including preoperative workup, operative technique, and results. Every patient had routine follow-ups, 4 weeks after the procedure and 1 year after surgery. RESULTS: The main symptom was chest pain in the area of the xiphoid. Conservative treatment trials with different combinations of analgesics over at least 1 year did not lead to insufficient and long-term improvement, which is why the decision for a surgical xiphoidectomy was eventually made. No postoperative complications occurred. Significant pain relief was achieved in eight out of ten patients; one patient was lost to long-term follow-up. Both patients with insufficient pain relief have had previous surgery in form of a sternotomy and upper median laparotomy. CONCLUSIONS: Xiphodynia is a diagnostic conundrum, which is why reports on its treatment including surgical resection of the xiphoid are even sparser. So far, this is the largest reported series of surgically treated xiphodynia. Correct diagnosis remains the key factor for success. While tenderness over the tip of the xiphoid process combined with protrusion of the xiphoid with a xiphisternal angle of <160° are good indications for surgery, patients after previous operations affecting the xiphoid process are less likely to benefit from xiphoidectomy.

Completely Thoracoscopic Diaphragmatic Plication.

BACKGROUND: Thoracoscopic diaphragmatic plication for diaphragmatic paralysis with consecutive eventration and respiratory compromise is a desirable alternative to standard thoracotomy. Since minimally invasive techniques usually involve suturing of the diaphragm, most surgeons use a video-assisted approach with a minithoracotomy. Herein we describe our completely thoracoscopic technique for diaphragmatic plication including outcome. METHODS: We present our technique and experience for completely thoracoscopic diaphragmatic plication for the treatment of symptomatic diaphragmatic paralysis in six consecutive patients. The surgical technique basically consisted of stapling of the abundant diaphragm and reinforcement of the staple line using a self-locking thread. Primary outcome measure was the postoperative result (flattened diaphragm) and resolution of symptoms. Secondary outcome was improvement of lung function values 3 months after surgery. RESULTS: Between June 2015 and March 2016, six patients have been operated for symptomatic diaphragmatic paralysis, with one of them suffering from additional transdiaphragmatic hernia. Flattening of the diaphragm was achieved in all 6 patients with resolution of their pre-existing symptoms within days after surgery and without any surgical complications. Lung function volumes measured 3 months postoperative improved markedly with an increase in FEV1 as well as FVC of 540 ml (SD ± 193 ml) and 776 ml (SD ± 121 ml), respectively. CONCLUSIONS: In our experience, the presented technique is a safe and simple minimally invasive way to perform a completely thoracoscopic diaphragmatic plication with excellent results so far.

Repair of sternoclavicular joint dislocations with FiberWire®.

PURPOSE: Up to 50% of traumatic sternoclavicular joint (SCJ) dislocations need open reduction and fixation to prevent long-term complications and complaints. We present our preferred surgical approach for acute as well as chronic SCJ dislocations, including their outcome. METHODS: Five consecutive male patients with a median age of 27 (range 20-49) were treated for traumatic anterior (n = 2) or posterior (n = 3) SCJ dislocation. Open reduction and surgical fixation were achieved by a modified figure-of-eight sutures using Fiberwire®. In anterior dislocations, an additional reconstruction of the costoclavicular ligament was performed. Median follow-up was 11 months (range 9-48) and included clinical evaluation and the use of the DASH questionnaire. RESULTS: Open surgical reduction and SCJ repair were successfully achieved in all patients without complications. Repair resulted in very good functional outcomes in all five patients with DASH scores of 0, 8 (n = 3) and 5, 8 (n = 2), respectively. CONCLUSIONS: The presented technique allowed simple, effective, and durable repair of the SCJ joint in patients with SCJ dislocations with excellent functional outcomes.

Is clipping the preferable technique to perform sympathicotomy? A retrospective study and review of the literature.

PURPOSE: Thoracoscopic sympathetic surgery is nowadays a broadly accepted technique in the treatment of primary hyperhidrosis as well as facial blushing. The objective of this study was to compare the two currently most commonly used methods for thoracic sympathicotomy: transection (ETS) and clipping (ETC.). METHODS: This is a retrospective study on a total of 63 patients, who underwent rib-oriented sympathicotomy, either by transection (n = 36, 57 %) or by clipping (n = 27, 43 %). Moreover, the up-to-date international literature is reviewed concerning which level(s) of the sympathetic trunk should be addressed, depending on the patients underlying condition. Furthermore, the highly controversial topic of reversibility of sympathetic clipping is debated. RESULTS: Our results confirm that clipping is at least as effective as transection of the sympathetic chain in the treatment of hyperhidrosis and facial blushing. Furthermore, the analysis of all larger studies on unclipping in humans shows a surprisingly high reported reversal rate between 48 and 77 %. CONCLUSIONS: Depending on the symptoms of the patient, different levels of the sympathetic chain should be addressed. When a higher rib level such as R2 is approached, which more likely will result in moderate to severe compensatory sweating, clipping should be preferred as it seems that this technique has indeed a potential for reversibility. As demonstrated, this method is at least as effective as an irreversible transection of the sympathetic chain.

Single-center clinical experience of extended sleeve lobectomy (ESL) versus standard sleeve lobectomy (SL).

Background: Sleeve lobectomy (SL) and extended SL (ESL), which aim to preserve pulmonary function and enhance the quality of life of patients while ensuring oncological outcomes, are valuable surgical options for the treatment of centrally located non-small cell lung cancer (NSCLC). This study aimed to compare perioperative adverse events and long-term survival between SL and ESL in NSCLC patients, providing a comprehensive review of surgical outcomes, complications, and survival to assess the roles of SL and ESL in thoracic oncology. Methods: This single-center retrospective study assessed the outcomes of NSCLC patients who underwent SL or ESL from June 2014 to January 2022. The patients were selected based on specific inclusion criteria, and statistical analyses were conducted to examine the postoperative outcomes, overall survival (OS), and disease-free survival (DFS) of the patients. Results: A total of 218 patients met the inclusion criteria. Among 218 patients, 33 underwent ESL and 185 underwent SL. Compared to SL, ESL was associated with longer operative times and higher R0 resection rates (93.9% vs. 78.8%, P=0.047). Despite the higher complexity of ESL compared to SL, there were no significant differences in the perioperative complications or mortality rates between the groups. Survival analysis was conducted on the propensity score matching (PSM) data, the results demonstrated superior OS and DFS in the ESL group compared to the SL group. Advanced age, more advanced nodal (N) status, and non-R0 resection were significant predictors of poorer prognosis. Conclusions: ESL is a feasible and effective alternative for treating centrally located NSCLC, with better R0 resection rates and comparable survival outcomes to SL, without increasing the risk of grade III-IV complications. Further studies with larger cohorts need to be conducted to validate these findings and refine the surgical techniques.

Comparative outcomes of video-assisted thoracoscopic surgery versus open surgery for bronchogenic cysts in adults: a retrospective cohort study.

Background: Open thoracotomy has been the traditional surgical approach for patients with bronchogenic cysts (BCs). This study aimed to evaluate the safety and efficacy of video-assisted thoracoscopic surgery (VATS) compared to open surgery for the treatment of BCs in adults. Methods: This single-institution, retrospective cohort study included 117 consecutive adult patients who underwent VATS (group A) or open surgery (group B) for BC resection between February 2019 and January 2023. Data regarding clinical history, operation duration, length of hospital stay, 30-day mortality, and recurrence during follow-up were collected and analyzed. Results: Of the total cohort, 103 (88.0%) patients underwent VATS, while 14 (12.0%) patients underwent open surgery. Patients' age in group B were much older than group A (P=0.014), and no significant differences in other demographic and baseline clinical characteristics were observed between the groups. The VATS group had shorter median operation duration (96 vs. 149.5 min, P<0.001) and shorter mean length of hospital stay (5.0±5.5 vs. 8.6±4.0 days, P<0.001). One death occurred in the open surgery group. During a median follow-up of 34 (interquartile range, 20.8-42.5) months, no instances of BC recurrence were observed in either group. Conclusions: Compared to open surgery, VATS is also a safe and efficacious approach for treating BCs in adults. What's more, VATS offered shorter operative times and hospital stays. Considering the minimally invasive, VATS may be a better choice in most patients with bronchial cysts.

A 24-Year-Old Man with Spontaneous Right Tension Pneumothorax Presenting with Abdominal Pain with an Initial Symptomatic Diagnosis of Acute Pancreatitis.

BACKGROUND Tension pneumothorax (TP) is a medical emergency resulting in air accumulation in the pleural cavity of the affected side. Later, this air applies pressure on the mediastinal structures, leading to a shift of these structures toward the contralateral side. This shift results in a picture of obstructive shock with a possibly fatal consequence if not detected and treated early. Treatment should not await radiological confirmation, and the red flags in the history and physical examination are enough to proceed with decompressing the affected hemithorax with a large-bore needle. Usually, patients with TP present to the Emergency Department with pleuritic chest pain and shortness of breath, but rare presentations are still possible. CASE REPORT We report a case of a 24-year-old male patient with TP who presented to the Emergency Department with severe epigastric abdominal pain with a clinical picture of acute pancreatitis. X-ray showed a right-sided TP. Immediately, we performed a needle decompression followed by chest tube insertion. Four days later, the patient was discharged home uneventfully. CONCLUSIONS In this case report, we aim to draw the attention of physicians in the Emergency Department to the need to consider the possibility of upper abdominal pain elicited by chest pathologies. Furthermore, we need to investigate the effect of TP on coronary perfusion.

Thoracic outlet syndrome: a retrospective analysis of robotic assisted first rib resections.

Thoracic Outlet Syndrome (TOS) is caused by compression of the neurovascular bundle between the first rib and the clavicula, which can cause a large panel of symptoms and has a reported incidence of approximately 2-4/100.000. Surgical treatment consists of the resection of the first rib and is historically performed using an open, mainly transaxillary, approach. Recent developments resulted in a minimally invasive approach using Robotic Assisted Thoracic Surgery (RATS). With this study, the investigators want to provide a descriptive study of first rib resection using RATS approach at two different centers. We reviewed the files of 47 patients affected by TOS and who benefited from first rib resection using RATS approach between 2016 and 2021. Patient characteristics as well as Length of Stay (LOS), affected side, operative time (OT), complications, etiology, VAS score and post-operative QOL were gathered in the database. Statistical analysis was performed using IBM SPSS statistics 25 ®. Results were reported in mean and standard deviation. 47 patients affected by TOS received first rib resection using robotic approach. Mean age was 47 ± 12 yrs. 16 patients were operated on the left side and 31 on the right side. All the patients reported complete resolution of symptoms. At 1-year follow-up, no patient suffered from recurrence. There were no intraoperative complications. Postoperative complications occurred in two patients, one patient developed pneumothorax after chest tube removal and one patient developed recurrent pleural effusion which required surgery. Mean LOS was 3 ± 1 days and mean OT was 122 ± 40 min. First rib resection performed using a RATS approach is a safe technique with excellent outcomes and which is beneficial for the patient in terms of LOS, pain and symptom resolution.

MEK1 drives oncogenic signaling and interacts with PARP1 for genomic and metabolic homeostasis in malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) is a lethal malignancy etiologically caused by asbestos exposure, for which there are few effective treatment options. Although asbestos carcinogenesis is associated with reactive oxygen species (ROS), the bona fide oncogenic signaling pathways that regulate ROS homeostasis and bypass ROS-evoked apoptosis in MPM are poorly understood. In this study, we demonstrate that the mitogen-activated protein kinase (MAPK) pathway RAS-RAF-MEK-ERK is hyperactive and a molecular driver of MPM, independent of histological subtypes and genetic heterogeneity. Suppression of MAPK signaling by clinically approved MEK inhibitors (MEKi) elicits PARP1 to protect MPM cells from the cytotoxic effects of MAPK pathway blockage. Mechanistically, MEKi induces impairment of homologous recombination (HR) repair proficiency and mitochondrial metabolic activity, which is counterbalanced by pleiotropic PARP1. Consequently, the combination of MEK with PARP inhibitors enhances apoptotic cell death in vitro and in vivo that occurs through coordinated upregulation of cytotoxic ROS in MPM cells, suggesting a mechanism-based, readily translatable strategy to treat this daunting disease. Collectively, our studies uncover a previously unrecognized scenario that hyperactivation of the MAPK pathway is an essential feature of MPM and provide unprecedented evidence that MAPK signaling cooperates with PARP1 to homeostatically maintain ROS levels and escape ROS-mediated apoptosis.

Combination of endobronchial bronchoscopic debulking and bronchoplastic segmentectomy of an obstructive neuroendocrine tumour: probably the least invasive approach.

We report the case of a female patient with an obstructing well-differentiated neuroendocrine tumour in the apical segment of the completely atelectatic right lower lobe. Bronchoscopic debulking of the tumour lead to re-ventilation of the remaining lobe, allowing to perform a lung-sparing bronchoplastic resection of the affected segment by uniportal video-assisted thoracic surgery.

A Breakthrough Brought about by Targeting KRASG12C: Nonconformity Is Punished.

KRAS is the most frequently mutated oncogene in lung carcinomas, accounting for 25% of total incidence, with half of them being KRASG12C mutations. In past decades, KRAS enjoyed the notorious reputation of being untargetable-that is, until the advent of G12C inhibitors, which put an end to this legend by covalently targeting the G12C (glycine to cysteine) substitution in the switch-II pocket of the protein, inhibiting the affinity of the mutant KRAS with GTP and subsequently the downstream signaling pathways, such as Raf/MEK/ERK. KRASG12C-selective inhibitors, e.g., the FDA-approved AMG510 and MRTX849, have demonstrated potent clinical efficacy and selectivity in patients with KRASG12C-driven cancers only, which spares other driver KRAS mutations (e.g., G12D/V/S, G13D, and Q61H) and has ushered in an unprecedented breakthrough in the field in recent decades. However, accumulating evidence from preclinical and clinical studies has shown that G12C-targeted therapeutics as single agents are inevitably thwarted by drug resistance, a persistent problem associated with targeted therapies. A promising strategy to optimize G12C inhibitor therapy is combination treatments with other therapeutic agents, the identification of which is empowered by the insightful appreciation of compensatory signaling pathways or evasive mechanisms, such as those that attenuate immune responses. Here, we review recent advances in targeting KRASG12C and discuss the challenges of KRASG12C inhibitor therapy, as well as future directions.

Operative versus non-operative management of rib fractures in flail chest after cardiopulmonary resuscitation manoeuvres.

OBJECTIVES: Blunt chest trauma after mechanical resuscitation manoeuvres appears to have a significant impact on the often complicated course. Due to a lack of data in the literature, the purpose of this study was to investigate the feasibility and immediate outcome of chest wall stabilization for flail chest in this vulnerable patient population. METHODS: We retrospectively reviewed the medical records of patients after cardiopulmonary resuscitation between January 2014 and December 2018 who were diagnosed with flail chest. We attempted to compare patients after surgery with those after conservative treatment. RESULTS: Of a total of 56 patients with blunt chest trauma after mechanical resuscitation and after coronary angiography, 25 were diagnosed with flail chest. After the exclusion of 2 patients because of an initial decision to palliate, 13 patients after surgical stabilization could be compared with 10 patients after conservative therapy. Although there was no significant difference in the total duration of ventilatory support, there was a significant advantage when the time after stabilization to extubation was compared with the duration of ventilation in the conservative group. The presence of pulmonary contusion, poor Glasgow Coma Scale score or the development of pneumonia negatively affected the outcome, but additional sternal fracture did not. CONCLUSIONS: Surgical stabilization for chest wall instability is well tolerated even by this vulnerable patient population. Our results should be used for further randomized controlled approaches. It is necessary to evaluate the situation with all parameters in an interdisciplinary manner and to decide on a possible surgical therapy at an early stage if possible.

Successful thoracoscopic management of iatrogenic left subclavian arterial injury: a case report.

The subclavian artery at the thoracic outlet is in the deepest position of the thoracic cavity and is difficult to repair in this narrow space once injured, even if the surgery is converted to a thoracotomy. This article presents a successful left subclavian artery repair procedure at the thoracic outlet using a thoracoscopic approach, with a video demonstration, and describes its technical characteristics. The patient was planned for a left upper lobectomy through three-port thoracoscopic approach. Severe adhesions were found intraoperatively and an accidental left subclavian arterial injury occurred when dissecting the adhesions. We first clamped the proximal portion of the subclavian artery and then directly clamped the rupture site. Our first suture failed due to the limited suture angle and the mutual restriction between the needle holder and atraumatic vascular clamp. To freely control the needle holder, another assistant port was made in the seventh intercostal space (ICS). The arterial injury was finally successfully repaired using pledgetted suture. The operation time was 235 minutes and intraoperative blood loss was 800 mL. The pulsation of the left radial artery was normal postoperatively, and the patient was discharged on postoperative day 6. Appropriate strategies allow attempts to manage intraoperative hyperbaric arterial bleeding from the systemic circulation, such as bleeding caused by subclavian arterial injuries, by means of a thoracoscopic approach without conversion to thoracotomy.

Surgical smoke: modern mobile smoke evacuation systems improve occupational safety in the operating theatre.

OBJECTIVES: Evaluation of smoke capture efficiency of different mobile smoke evacuation devices with respect to volatile organic compounds and their noise emission. METHODS: Electrosurgical incisions were performed on fresh porcine liver in an operating room with vertical laminar flow. The generated surgical smoke was analysed with proton-transfer-reaction mass spectrometry with and without the use of a mobile smoke evacuation system consisting of a smoke evacuator machine, a suction hose and a handpiece. The inlet of the mass spectrometer was positioned 40 cm above the specimen. Various devices were compared: a hard plastic funnel, a flexible foam funnel, an on-tip integrated aspirator of an electrosurgical knife and a standard secretion suction (Yankauer). Also, sound levels were measured at a distance of 40 cm from the handpieces' inlet. RESULTS: The smoke capture efficiency of the secretion suction was only 53%, while foam funnel, plastic funnel and integrated aspirator were all significantly more effective with a clearance of 95%, 91% and 91%, respectively. The mean sound levels were 68 and 59 A-weighted decibels with the plastic and foam funnel, respectively, 66 A-weighted decibels with the integrated aspirator and 63 A-weighted decibels with the secretion suction. CONCLUSIONS: Carcinogenic, mutagenic and reprotoxic volatile organic compounds in surgical smoke can be efficiently reduced by mobile smoke evacuation system, providing improved protection for medical personnel. Devices specifically designed for smoke evacuation are more efficient than standard suction tools. Noise exposure for the surgeon was lowest with the flexible foam funnel and higher with the other handpieces tested.

Completely Thoracoscopic 3-Port Robotic First Rib Resection for Thoracic Outlet Syndrome.

BACKGROUND: In thoracic outlet syndrome, the constriction between bony and muscular structures leads to compression of the neurovascular bundle to the upper extremity. Traditional surgical techniques using supraclavicular, infraclavicular, or transaxillary approaches to remove the first rib do not usually allow good exposure of the entire rib and neurovascular bundle. We have therefore developed a robotic approach to overcome these limitations. METHODS: Between January 2015 and November 2020, 38 consecutive first rib resections for neurogenic, venous, or arterial thoracic outlet syndrome were performed in 34 patients at our institutions. For our completely portal approach, we used two 8-mm working ports and one 12-mm camera port. RESULTS: The surgery time was between 71 and 270 minutes (median ± SD: 133 ± 44.7 minutes) without any complications. Chest tube was removed on postoperative day 1 in all patients and the hospital stay after surgery ranged from 1-7 days (2 ± 2.1 days). No relevant intraoperative or postoperative complications were observed and complete or subtotal resolution of symptoms was seen in all patients. CONCLUSIONS: The robotic technique described here for first rib resection has proven to be a safe and effective approach. The unsurpassed exposure of the entire first rib and possibility for a robotic-assisted meticulous surgical dissection has prevented both intraoperative and postoperative complications. This makes this technique unique as the safest and most minimally invasive approach to date. It helps improve patient outcomes by reducing perioperative morbidity with an easily adoptable procedure.

Tumor-infiltrating lymphocytes are functionally inactivated by CD90+ stromal cells and reactivated by combined Ibrutinib and Rapamycin in human pleural mesothelioma.

Rationale: Despite evidence suggesting that the tumor microenvironment (TME) in malignant pleural mesothelioma (MPM) is linked with poor prognosis, there is a lack of studies that functionally characterize stromal cells and tumor-infiltrating lymphocytes (TILs). Here, we aim to characterize the stromal subsets within MPM, investigate their relationship to TILs, and explore the potential therapeutic targets. Methods: We curated a core set of genes defining stromal/immune signatures expressed by mesenchymal cells within the TME using molecular analysis of The Cancer Genome Atlas (TCGA) MPM cohort. Stromal and immune profiles were molecularly characterized using flow cytometry, immunohistochemistry, microarray, and functionally evaluated using T cell-activation/expansion, coculture assays and drug compounds treatment, based on samples from an independent MPM cohort. Results: We found that a high extracellular matrix (ECM)/stromal gene signature, a high ECM score, or the ratio of ECM to an immune activation gene signature are significantly associated with poor survival in the MPM cohort in TCGA. Analysis of an independent MPM cohort (n = 12) revealed that CD8+ and CD4+ TILs were characterized by PD1 overexpression and concomitant downregulation in degranulation and CD127. This coincided with an increase in CD90+ cells that overexpressed PD-L1 and were enriched for ECM/stromal genes, activated PI3K-mTOR signaling and suppressed T cells. Protein array data demonstrated that MPM samples with high PD-L1 expression were most associated with activation of the mTOR pathway. Further, to reactivate functionally indolent TILs, we reprogrammed ex vivo TILs with Ibrutinib plus Rapamycin to block interleukin-2-inducible kinase (ITK) and mTOR pathways, respectively. The combination treatment shifted effector memory (TEM) CD8+ and CD4+ TILs towards T cells that re-expressed CD45RA (TEMRA) while concomitantly downregulating exhaustion markers. Gene expression analysis confirmed that Ibrutinib plus Rapamycin downregulated coinhibitory and T cell signature pathways while upregulating pathways involved in DNA damage and repair and immune cell adhesion and migration. Conclusions: Our results suggest that targeting the TME may represent a novel strategy to redirect the fate of endogenous TILs with the goal of restoring anti-tumor immunity and control of tumor growth in MPM.

Metabolic synthetic lethality by targeting NOP56 and mTOR in KRAS-mutant lung cancer.

BACKGROUND: Oncogenic KRAS mutations are prevalent in human cancers, but effective treatment of KRAS-mutant malignancies remains a major challenge in the clinic. Increasing evidence suggests that aberrant metabolism plays a central role in KRAS-driven oncogenic transformation. The aim of this study is to identify selective metabolic dependency induced by mutant KRAS and to exploit it for the treatment of the disease. METHOD: We performed an integrated analysis of RNAi- and CRISPR-based functional genomic datasets (n = 5) to identify novel genes selectively required for KRAS-mutant cancer. We further screened a customized library of chemical inhibitors for candidates that are synthetic lethal with NOP56 depletion. Functional studies were carried out by genetic knockdown using siRNAs and shRNAs, knockout using CRISPR/Cas9, and/or pharmacological inhibition, followed by cell viability and apoptotic assays. Protein expression was determined by Western blot. Metabolic ROS was measured by flow cytometry-based quantification. RESULTS: We demonstrated that nucleolar protein 5A (NOP56), a core component of small nucleolar ribonucleoprotein complexes (snoRNPs) with an essential role in ribosome biogenesis, confers a metabolic dependency by regulating ROS homeostasis in KRAS-mutant lung cancer cells and that NOP56 depletion causes synthetic lethal susceptibility to inhibition of mTOR. Mechanistically, cancer cells with reduced NOP56 are subjected to higher levels of ROS and rely on mTOR signaling to balance oxidative stress and survive. We also discovered that IRE1α-mediated unfolded protein response (UPR) regulates this process by activating mTOR through p38 MAPK. Consequently, co-targeting of NOP56 and mTOR profoundly enhances KRAS-mutant tumor cell death in vitro and in vivo. CONCLUSIONS: Our findings reveal a previously unrecognized mechanism in which NOP56 and mTOR cooperate to play a homeostatic role in the response to oxidative stress and suggest a new rationale for the treatment of KRAS-mutant cancers.