TC2N inhibits distant metastasis and stemness of breast cancer via blocking fatty acid synthesis.

BACKGROUND: Tandem C2 domains, nuclear (TC2N) is a C2 domain-containing protein that belongs to the carboxyl-terminal type (C-type) tandem C2 protein family, and acts as an oncogenic driver in several cancers. Previously, we preliminarily reported that TC2N mediates the PI3K-Akt signaling pathway to inhibit tumor growth of breast cancer (BC) cells. Beyond that, its precise biological functions and detailed molecular mechanisms in BC development and progression are not fully understood. METHODS: Tumor tissues of 212 BC patients were subjected to tissue microarray and further assessed the associations of TC2N expression with pathological parameters and FASN expression. The protein levels of TC2N and FASN in cell lines and tumor specimens were monitored by qRT-PCR, WB, immunofluorescence and immunohistochemistry. In vitro cell assays, in vivo nude mice model was used to assess the effect of TC2N ectopic expression on tumor metastasis and stemness of breast cancer cells. The downstream signaling pathway or target molecule of TC2N was mined using a combination of transcriptomics, proteomics and lipidomics, and the underlying mechanism was explored by WB and co-IP assays. RESULTS: Here, we found that the expression of TC2N remarkedly silenced in metastatic and poorly differentiated tumors. Function-wide, TC2N strongly inhibits tumor metastasis and stem-like properties of BC via inhibition of fatty acid synthesis. Mechanism-wise, TC2N blocks neddylated PTEN-mediated FASN stabilization by a dual mechanism. The C2B domain is crucial for nuclear localization of TC2N, further consolidating the TRIM21-mediated ubiquitylation and degradation of FASN by competing with neddylated PTEN for binding to FASN in nucleus. On the other hand, cytoplasmic TC2N interacts with import proteins, thereby restraining nuclear import of PTEN to decrease neddylated PTEN level. CONCLUSIONS: Altogether, we demonstrate a previously unidentified role and mechanism of TC2N in regulation of lipid metabolism and PTEN neddylation, providing a potential therapeutic target for anti-cancer.

Mediastinal Cryobiopsy for Pathological Diagnosis of Fibrosing Mediastinitis-Associated Pulmonary Hypertension.

INTRODUCTION: Fibrosing mediastinitis is a benign but fatal disorder characterized by the proliferation of fibrous tissue in the mediastinum, causing encasement of mediastinal organs and extrinsic compression of adjacent bronchovascular structures. FM-associated pulmonary hypertension (FM-PH) is a serious complication of FM, resulting from the external compression of lung vessels. Pathologic assessment is important for etiologic diagnosis and effective treatment of this disease. CASE PRESENTATION: A 59-year-old male patient presented at our hospital and was diagnosed with FM-PH. He declined surgical biopsy that is the reference standard for pathologic assessment, in consideration of the potential risks. Therefore, an endobronchial ultrasound examination was performed, which identified the subcarinal lesion. Under ultrasound guidance, four needle aspirations were carried out, followed by one cryobiopsy. Histopathological examination of transbronchial needle aspiration specimens was inconclusive, while samples from cryobiopsy suggested a diagnosis of idiopathic FM. Further immunophenotyping demonstrated the infiltration of lymphocytes, macrophages, and FOXP3-positive cells in FM-PH. CONCLUSION: Mediastinal cryobiopsy might be a novel and safe option for FM-PH patients who are unwilling or unsuitable for surgical procedure.

SMARCA4-Deficient Undifferentiated Tumor Achieved by Transbronchial Mediastinal Cryobiopsy Additional to Needle Aspiration.

Lung cancer is the leading cause of deaths from malignant neoplasms worldwide, and a satisfactory biopsy that allows for histological and other analyses is critical for its diagnosis. Guidelines have recommended endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) as the reference standard for the staging of lung cancer. However, the relatively limited sample volume retrieved by needle aspiration might restrict the diagnostic capacity of EBUS-TBNA in other uncommon thoracic tumors. Transbronchial mediastinal cryobiopsy is a recently developed sampling strategy for mediastinal lesions, which demonstrates added diagnostic value to conventional needle aspiration. Here, we present a case of thoracic SMARCA4-deficient undifferentiated tumor successfully diagnosed by mediastinal cryobiopsy additional to EBUS-TBNA.

Primary Mediastinal Large B-Cell Lymphoma Achieved by Non-Cautery Assisted Transbronchial Mediastinal Cryobiopsy.

Transbronchial mediastinal cryobiopsy is a novel sampling strategy that shows improved diagnostic utility for mediastinal lesions, particularly in rare tumors and benign disorders, as compared to standard endobronchial ultrasound-guided transbronchial needle aspiration. During this procedure, electrocautery incision is frequently needed to advance the cryoprobe through the airway into the mediastinal lesion, which however results in increased operative difficulty and prolonged procedural time. Here we present a case of mediastinal large B-cell lymphoma successfully diagnosed by transbronchial mediastinal cryobiopsy without cautery-induced airway incision.

Mediastinal Nodular Lymphocyte Predominant Hodgkin Lymphoma Achieved by Endoscopic Transesophageal Cryobiopsy.

Guidelines have recommended endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and endoscopic ultrasound-guided fine-needle aspiration biopsy as initial sampling approaches of mediastinal lymph nodes for lung cancer staging. However, the small sample volume might restrict the diagnostic utility of needle aspiration in certain mediastinal diseases. We have recently shown that transbronchial mediastinal cryobiopsy, which is capable of providing larger amounts of intact tissue, improves diagnostic yield in rare tumors and benign diseases compared to EBUS-TBNA. Here, we present a case of mediastinal nodular lymphocyte predominant Hodgkin lymphoma successfully diagnosed by endoscopic transesophageal cryobiopsy.

Transbronchial mediastinal cryobiopsy in the diagnosis of mediastinal lesions: a randomised trial.

BACKGROUND: Guidelines recommend endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) as an initial investigatory technique for mediastinal nodal staging in lung cancer. However, EBUS-TBNA can be limited by the inadequacy of intact tissues, which might restrict its diagnostic yield in mediastinal lesions of certain aetiologies. We have previously shown that EBUS-guided transbronchial mediastinal cryobiopsy can provide intact samples with greater volume. METHODS: This randomised study determined the diagnostic yield and safety of transbronchial mediastinal cryobiopsy monitored by endosonography for the diagnosis of mediastinal lesions. Patients with a mediastinal lesion of ≥1 cm in the short axis were recruited. Following identification of the mediastinal lesion by linear EBUS, fine-needle aspiration and cryobiopsy were sequentially performed in a randomised order. Primary end-points were diagnostic yield, defined as the percentage of patients for whom mediastinal biopsy provided a definite diagnosis, and procedure-related adverse events. RESULTS: In total, 197 patients were enrolled and randomly allocated. The overall diagnostic yield was 79.9% and 91.8% for TBNA and transbronchial mediastinal cryobiopsy, respectively (p=0.001). Diagnostic yields were similar for metastatic lymphadenopathy (94.1% versus 95.6%, p=0.58), while cryobiopsy was more sensitive than TBNA in uncommon tumours (91.7% versus 25.0%, p=0.001) and benign disorders (80.9% versus 53.2%, p=0.004). No significant differences in diagnostic yield were detected between "TBNA first" and "Cryobiopsy first" groups. We observed two cases of pneumothorax and one case of pneumomediastinum. CONCLUSIONS: Transbronchial cryobiopsy performed under EBUS guidance is a safe and useful approach that offers diagnostic histological samples of mediastinal lesions.

Primary Mediastinal Seminoma Achieved by Transbronchial Mediastinal Cryobiopsy.

Mediastinal biopsy is essential for the clinical diagnosis of mediastinal disease. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a well-established approach for obtaining diagnostic samples from mediastinal masses or enlarged lymph nodes which is proven to be minimally invasive and effective. However, the insufficiency of intact samples acquired might restrict the diagnostic efficacy of EBUS-TBNA for mediastinal lesions such as rare malignancy and granulomatous disorder. We here present an EBUS-guided approach for the cryobiopsy of mediastinal diseases that is capable of providing larger amounts of intact tissue with few observed complications.

Transbronchial needle aspiration combined with cryobiopsy in the diagnosis of mediastinal diseases: a multicentre, open-label, randomised trial.

BACKGROUND: Transbronchial mediastinal cryobiopsy is a novel sampling technique for mediastinal disease. Despite the possibility of lung cancer misdiagnosis, the improved diagnostic yield of this approach for non-lung-cancer lesions compared with standard endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) highlights its diagnostic potential as a complementary technique to conventional biopsy. We aimed to evaluate the safety profile and added value of the combined use of transbronchial mediastinal cryobiopsy and standard EBUS-TBNA for the diagnosis of mediastinal diseases. METHODS: We conducted an open-label, randomised trial at three hospital sites in Europe and Asia. Eligible patients were aged 15 years or older, with at least one mediastinal lesion of 1 cm or longer in the short axis that required diagnostic bronchoscopy. Participants were randomly assigned (1:1) using a block randomisation scheme generated by a computer (block size of four participants based on a random table from an independent statistician) to the combined use of EBUS-TBNA and transbronchial mediastinal cryobiopsy (combined group) or EBUS-TBNA alone (control group). Because of the nature of the intervention, neither participants nor investigators were masked to group assignment. The coprimary outcomes were differences in procedure-related complications and diagnostic yield (defined as the proportion of participants for whom mediastinal biopsy led to a definitive diagnosis), assessed in the full analysis set, including all the patients who met the eligibility criteria and had a biopsy. A fully paired, intraindividual diagnostic analysis in participants who had both needle aspiration and mediastinal cryobiopsy was conducted, in addition to interindividual comparisons. This trial is now complete and is registered with ClinicalTrials.gov, NCT04572984. FINDINGS: Between Oct 12, 2020, and Sept 9, 2021, 297 consecutive patients were assessed for eligibility and 271 were enrolled and randomly assigned to the combined group (n=136) or the control group (n=135). The addition of cryobiopsy to standard sampling significantly increased the overall diagnostic yield for mediastinal lesions, as shown by both interindividual (126 [93%] of 136 participants in the combined group vs 109 [81%] of 135 in the control group; risk ratio [RR] 1·15 [95% CI 1·04-1·26]; p=0·0039) and intraindividual (126 [94%] of 134 vs 110 [82%] of 134; RR 1·15 [95% CI 1·05-1·25]; p=0·0026) analyses. In subgroup analyses in the intraindividual population, diagnostic yields were similar for mediastinal metastasis (68 [99%] of 69 participants in the combined group vs 68 [99%] of 69 in the control group; RR 1·00 [95% CI 0·96-1·04]; p=1·00), whereas the combined approach was more sensitive than standard needle aspiration in benign disorders (45 [94%] of 48 vs 32 [67%] of 48; RR 1·41 [95% CI 1·14-1·74]; p=0·0009). The combined approach also resulted in an improved suitability of tissue samples for molecular and immunological analyses of non-small-cell lung cancer. The incidence of adverse events related to the biopsy procedure did not differ between trial groups, as grade 3-4 airway bleeding occurred in three (2%) patients in the combined group and two (1%) in the control group (RR 0·67 [95% CI 0·11-3·96]; p=1·00). There were no severe complications causing death or disability. INTERPRETATION: The addition of mediastinal cryobiopsy to standard EBUS-TBNA resulted in a significant improvement in diagnostic yield for mediastinal lesions, with a good safety profile. These data suggest that this combined approach is a valid first-line diagnostic tool for mediastinal diseases. FUNDING: National Natural Science Foundation of China.

Overexpression of chemokine receptor lymphotactin receptor 1 has prognostic value in clear cell renal cell carcinoma.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is an aggressive subtype of renal cell carcinoma. X-C motif chemokine receptor 1 (XCR1) exerts important roles in tumor progression; however, its role in ccRCC is unclear. METHODS: We utilized publicly available data from The Cancer Genome Atlas (TCGA) to assess the role of XCR1 in ccRCC and validated the results in 36 samples from patients with ccRCC who underwent curative resection in Xinqiao Hospital Chongqing. XCR1 overexpression was identified in ccRCC, which was confirmed by qRT-PCR assay and immunohistochemical staining of ccRCC samples. RESULTS: For the TCGA and clinical data, Kaplan-Meier survival analysis revealed that higher XCR1 expression in ccRCC was related to longer overall survival. Cox regression analysis suggested that XCR1 is an independent risk factor for ccRCC. GSEA analysis suggested that XCR1 is associated with the JAK/STAT signaling pathway. XCR1 knockdown by small interfering RNA (siRNA) significantly increased ccRCC cell proliferation and migration, and decreased cell apoptosis. CONCLUSION: We found higher XCR1 expression in ccRCC compared with that in normal tissues is related to longer overall survival in patients with ccRCC. XCR1 knockdown significantly increased RCC cells proliferation and migration, and decreased apoptosis. XCR1 might be used as a prognostic biomarker in ccRCC in the future.

Increased Expression and Cellular Localization of P2X7R in Cortical Lesions of Patients With Focal Cortical Dysplasia.

Focal cortical dysplasias (FCDs) are major brain malformations that commonly lead to medically intractable epilepsy. The purinergic ionotropic P2X7 receptor (P2X7R) is an atypical P2X subtype that gates calcium and sodium ions. Previous animal studies have suggested that P2X7R is a contributing factor in epileptogenesis. This study aimed to define the distribution and expression of P2X7R in 35 FCD patient-surgical-resection specimens relative to autopsy control samples (n = 8). Immunohistochemical colocalization assays revealed that P2X7R was primarily expressed in neurons, astrocytes, and microglia. In FCD samples, P2X7R protein levels were increased in abnormal cell types such as dysmorphic neurons and balloon cells, which are characteristic of FCD. By real-time PCR and Western blotting, P2X7R mRNA and protein expression levels were elevated in FCD patient samples vs control samples; P2X7R expression was also higher in FCDII vs FCDIa patient samples. Because interleukin-1ß is a downstream factor of the P2X7R signaling pathway, we determined that there was also moderate-to-strong interleukin-1ß expression in the dysmorphic neurons, balloon cells, and microglia in FCD patient lesions. These results indicate that increasing P2X7R levels may contribute to the pathogenesis of human FCD and that P2X7R represents a potential anti-epileptogenic target.