Gas Gangrene of the Spleen Caused by Clostridium perfringens After Mild Blunt Trauma.

Splenic gas gangrene caused by Clostridium perfringens is rare. A 73-year-old woman was referred to our hospital because of fatigue, dyspnea, and left hypochondrial pain. She had a history of blunt trauma to the left abdomen eight days ago. She presented with hypoxemia and a high inflammatory response on blood tests. A CT showed left pleural effusion and gas in the spleen. She was treated with antimicrobials and underwent splenectomy. C. perfringens was identified from blood and intraoperative ascites cultures. She recovered and was discharged on day 34 of hospitalization. As C. perfringens is part of the normal gut microbiota and can translocate to other parts of the body, this bacterium should be considered a splenic abscess pathogen when an intracorporeal anaerobic environment is suspected.

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.

Incidence of phrenic nerve injury during pulmonary vein isolation using different cryoballoons: data from a large prospective ablation registry.

AIMS: Phrenic nerve injury (PNI) is the most common complication during cryoballoon ablation. Currently, two cryoballoon systems are available, yet the difference is unclear. We sought to compare the acute procedural efficacy and safety of the two cryoballoons. METHODS: This prospective observational study consisted of 2,555 consecutive atrial fibrillation (AF) patients undergoing pulmonary vein isolation (PVI) using either conventional (Arctic Front Advance) (AFA-CB) or novel cryoballoons (POLARx) (POLARx-CB) at 19 centers between January 2022 and October 2023. RESULTS: Among 2,555 patients (68.8 ± 10.9 years, 1,740 men, paroxysmal AF[PAF] 1,670 patients), PVIs were performed by the AFA-CB and POLARx-CB in 1,358 and 1,197 patients, respectively. Touch-up ablation was required in 299(11.7%) patients. The touch-up rate was significantly lower for POLARx-CB than AFA-CB (9.5% vs. 13.6%, p = 0.002), especially for right inferior PVs (RIPVs). The touch-up rate was significantly lower for PAF than non-PAF (8.8% vs. 17.2%, P < 0.001) and was similar between the two cryoballoons in non-PAF patients. Right PNI occurred in 64(2.5%) patients and 22(0.9%) were symptomatic. It occurred during the right superior PV (RSPV) ablation in 39(1.5%) patients. The incidence was significantly higher for POLARx-CB than AFA-CB (3.8% vs. 1.3%, P < 0.001) as was the incidence of symptomatic PNI (1.7% vs. 0.1%, P < 0.001). The difference was significant during RSPV (2.5% vs. 0.7%, P < 0.001) but not RIPV ablation. The PNI recovered more quickly for the AFA-CB than POLARx-CB. CONCLUSIONS: Our study demonstrated a significantly higher incidence of right PNI and lower touch-up rate for the POLARx-CB than AFA-CB in the real-world clinical practice.

A Case of Aggressive Lung Squamous Cell Carcinoma With Aberrant Cytoplasmic p53 Aggregation.

Background: Immunohistochemistry for p53 was a well-established method for cancer diagnosis in pathology. Aberrant cytoplasmic p53 positivity reflects the accumulation of p53 aggregates, which has been shown to be associated with chemoresistance and to be a predictive marker of a worse clinical course in ovarian cancer. Case Report: A 65-year-old Japanese man was diagnosed with lung cancer, and surgical resection was performed. Multiple metastasis were found 21 months post-surgery. The lesions were resistant to chemotherapy, and he succumbed to the disease 29 months post-surgery. The resected primary lesion was pathologically diagnosed as squamous cell carcinoma, with notable cytoplasmic p53 positivity indicated by immunohistochemistry. Conclusion: Notable aberrant cytoplasmic accumulation of p53 aggregate was observed in the cancer cells of this case. Chemotherapy was ineffective for the recurrent lesions, suggesting a role of p53 aggregates in chemoresistance. Pathological analysis of p53 via immunohistochemistry may be useful in predicting chemoresistance of lung squamous cell carcinoma.

Tracheostomy for the pediatric patient with fibrodysplasia ossificans progressiva: a case report.

BACKGROUND: Fibrodysplasia ossificans progressiva (FOP) is an extremely rare connective tissue disease characterized by subsequent ossification of skeletal muscles, tendons, ligaments, and other fibrous tissues. The ossification of these tissues progresses during childhood and leads to limb and trunk deformities. Since any surgery may trigger subsequent ossification, it is relatively contraindicated for patients with FOP. In this report, we describe our experience in performing tracheostomy in a pediatric patient with FOP who developed a restrictive respiratory disorder due to progressive deformity of the trunk. CASE PRESENTATION: A 12-year-old boy, diagnosed with FOP at the age of one, was referred for a tracheotomy after requiring 2 months of oral intubation and mechanical ventilation due to severe deformity-induced dyspnea. After changing from oral intubation to nasal intubation, we carefully considered the indications and benefits of tracheostomy in patients with FOP. Eventually, tracheostomy was successfully performed using our surgical design: creating a skin incision at the level of the cricoid cartilage that can always be identified, creating inverted U-shaped incision on the anterior tracheal wall to make a flap, and suturing the entire circumference of the tracheotomy and skin. One month after the surgery, he regained normal breathing and pronunciation and returned to school. The patient showed no unfavorable postoperative outcomes over a 4-year follow-up period. CONCLUSIONS: Tracheostomy in our pediatric case of FOP required careful perioperative management. However, it could effectively improve the patient's quality of life.

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.

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.

Duodenal Papillary Metastasis of Lung Cancer with Bleeding Controlled by Endoscopic Treatment and Systemic Osimertinib Therapy: Case Report.

Introduction: Solid organ malignancies rarely metastasize to the duodenal papilla. We describe a case of primary lung cancer with duodenal papillary metastasis in a patient who presented with melena. To the best of our knowledge, this is only the second report of duodenal papillary metastasis from lung cancer. Case Presentation: A 65-year-old woman presented with complaints of anorexia, weight loss, and black stool. Imaging studies led to a clinical diagnosis of stage IVB lung cancer, and anticoagulants were initiated to treat pulmonary artery thrombosis. However, endoscopic hemostasis was challenging because of bleeding from a duodenal papillary tumor. Fortunately, the patient was positive for the plasma epidermal growth factor receptor (EGFR) gene mutation, and osimertinib, an EGFR tyrosine kinase inhibitor, was administered, successfully achieving hemostasis. Subsequently, endoscopic ultrasonography-guided transbronchial needle aspiration of an enlarged mediastinal lymph node and duodenal papillary tumor biopsy confirmed duodenal papillary metastasis of the primary lung adenocarcinoma. Conclusion: Although duodenal papillary metastasis is extremely rare, a good clinical outcome was achieved in this case by considering duodenal papillary metastasis from lung cancer as the differential diagnosis and administering systemic osimertinib therapy.

Molecular Imaging of PD-1 Unveils Unknown Characteristics of PD-1 Itself by Visualizing "PD-1 Microclusters".

Programmed cell death-1 (PD-1) is one of the most famous coinhibitory receptors that are expressed on effector T cells to regulate their function. The PD-1 ligands, PD-L1 and PD-L2, are expressed by various cells throughout the body at steady state and their expression was further regulated within different pathological conditions such as tumor-bearing and chronic inflammatory diseases. In recent years, immune checkpoint inhibitor (ICI) therapies with anti-PD-1 or anti-PD-L1 has become a standard treatment for various malignancies and has shown remarkable antitumor effects. Since the discovery of PD-1 in 1992, a huge number of studies have been conducted to elucidate the function of PD-1. Herein, this paper provides an overview of PD-1 biological findings and sheds some light on the current technology for molecular imaging of PD-1.

IL-32 production from lung adenocarcinoma cells is potentially involved in immunosuppressive microenvironment.

Interleukin 32 (IL-32) is a proinflammatory cytokine secreted from several kinds of cancer cells. In the present study, we investigated the significance of IL-32 in lung adenocarcinoma by immunohistochemistry and bioinformatics analysis. IL-32 was positive in cancer cells of 21 cases (9.2%) of total 228 cases. Increased IL-32 gene expression was linked to worse clinical course in TCGA analysis, however, IL-32 expression in immunohistochemistry was not associated to clinical course in our cohort. It was also found that high IL-32 expression was seen in cases with increased lymphocyte infiltration. In vitro studies indicated that IFN-γ induced gene expression of IL-32 and PD1-ligands in lung adenocarcinoma cell lines. IL-32, especially IL-32ß, also induced overexpression of PD1-ligands in human monocyte-derived macrophages. Additionally, Cancer-cell-derived IL-32 was elevated by stimulation with anticancer agents. In conclusion, IL-32 potentially induced by inflammatory conditions and anticancer therapy and contribute to immune escape of cancer cells via development the immunosuppressive microenvironment. IL-32 might be a target molecule for anti-cancer therapy.

Efficacy and safety of add-on mirogabalin to conventional therapy for the treatment of peripheral neuropathic pain after thoracic surgery: the multicenter, randomized, open-label ADMIT-NeP study.

BACKGROUND: For chronic pain after thoracic surgery, optimal timing of its diagnosis and effective treatment remains unresolved, although several treatment options are currently available. We examined the efficacy and safety of mirogabalin, in combination with conventional pain therapy (nonsteroidal anti-inflammatory drugs and/or acetaminophen), for treating peripheral neuropathic pain (NeP) after thoracic surgery. METHODS: In this multicenter, randomized, open-label, parallel-group study, patients with peripheral NeP were randomly assigned 1:1 to mirogabalin as add-on to conventional therapy or conventional treatment alone. RESULTS: Of 131 patients of consent obtained, 128 were randomized (mirogabalin add-on group, 63 patients; conventional treatment group, 65 patients). The least squares mean changes (95% confidence interval [CI]) in Visual Analogue Scale (VAS) score for pain intensity at rest from baseline to Week 8 (primary endpoint) were - 51.3 (- 54.9, - 47.7) mm in the mirogabalin add-on group and - 47.7 (- 51.2, - 44.2) mm in the conventional group (between-group difference: - 3.6 [95% CI: - 8.7, 1.5], P = 0.161). However, in patients with Self-administered Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) score (used for the screening of NeP) ≥ 12 at baseline, the greater the S-LANSS score at baseline, the greater the decrease in VAS score in the mirogabalin add-on group, while no such trend was observed in the conventional treatment group (post hoc analysis). This between-group difference in trends was statistically significant (interaction P value = 0.014). Chronic pain was recorded in 7.9% vs. 16.9% of patients (P = 0.171) at Week 12 in the mirogabalin add-on vs. conventional treatment groups, respectively. Regarding activities of daily living (ADL) and quality of life (QOL), changes in Pain Disability Assessment Scale score and the EQ-5D-5L index value from baseline to Week 8 showed significant improvement in the mirogabalin add-on group vs. conventional treatment group (P < 0.001). The most common adverse events (AEs) in the mirogabalin add-on group were dizziness (12.7%), somnolence (7.9%), and urticaria (3.2%). Most AEs were mild or moderate in severity. CONCLUSIONS: Addition of mirogabalin to conventional therapy did not result in significant improvement in pain intensity based on VAS scores, but did result in significant improvement in ADL and QOL in patients with peripheral NeP after thoracic surgery. TRIAL REGISTRATION: Japan Registry of Clinical Trials jRCTs071200053 (registered 17/11/2020).

Treatment of ZC4H2 Variant-Associated Spastic Paraplegia with Selective Dorsal Rhizotomy and Intensive Postoperative Rehabilitation: A Case Report.

Selective dorsal rhizotomy (SDR) has been used to treat children with spastic cerebral palsy (CP), and its beneficial effect on quality of life and ambulation has been confirmed in long-term follow-up studies. However, the role of SDR in the treatment of spasticity in patients with hereditary spastic paraplegia (HSP) and related disorders is not well-established. Here, we report the first patient with the ZC4H2 variant who underwent SDR to treat spastic paraplegia. Abnormal gait was discovered during a regular checkup at the age of 3 years and 9 months, and she was diagnosed with spastic paraplegia. She was heterozygous for the ZC4H2 variant and underwent SDR at the age of 5 years and 11 months, which alleviated the spasticity. The patient underwent inpatient postoperative rehabilitation for 4 months and continued outpatient physiotherapy after discharge. The Gross Motor Function Measure-88 score and maximum walking speed decreased transiently 1 month postoperatively, but gradually recovered, and continuously improved 6 months postoperatively. SDR and postoperative intensive rehabilitation were effective in improving motor and walking functions up to 6 months after surgery, although long-term follow-up is needed to draw conclusions.

Machine Learning for Multi-Vessel Coronary Artery Disease Prediction on Electrocardiogram Gated Single-Photon Emission Computed Tomography.

Background: Single-photon emission computed tomography (SPECT) encounters difficulties in diagnosing severe multi-vessel coronary artery disease (svMVD) because of balanced ischemia. We estimated the predictive value of electrocardiogram-gated SPECT for svMVD and improved it using machine learning (ML). Methods and results: We enrolled consecutive 335 patients (median age, 74 years; 255 men) who underwent adenosine stress-gated SPECT (99mTechnesium) and coronary angiography. svMVD was defined as three-vessel disease or left main tract stenosis. Predictive models were constructed using statistical and ML methods. Eighteen cases (5%) showed svMVD, and diabetes, summed stress score (SSS), and the max difference among segmental time of stroke volume per cardiac cycle (MDSV: a parameter of left ventricular [LV] end-systolic dyssynchrony) on adenosine stress were independent significant predictors. The area under the receiver operating characteristic curve (AUC) of SSS and MDSV on stress were 0.759 and 0.763, respectively. Conversely, the extra trees classifier and light gradient boosting machine had improved AUC values of 0.826 and 0.870, respectively, and the MDSV on stress and diabetes showed high feature values in the ML models. Conclusion: ML on SPECT helped to improve the diagnostic performance of svMVD and diabetes, and the parameters of LV dyssynchrony played essential roles in the ML predictive models.

[Risk Factors, Prevention, Diagnosis, and Treatment of Bronchopleural Fistula After Lung Resection].

Postoperative bronchopleural fistula (BPF) is a rare but severe and sometimes life-threatening complication that needs immediate and proper treatment. Thoracic surgeons should strictly manage the comorbidities such as diabetes mellitus for BPF prevention. Also, coverage of the bronchial stump with pericardial fat tissue will prevent BPF, or at least prevent the turning severe of BPF. However, when BPF occurs, we must promptly determine whether to perform conservative treatment or invasive treatment such as fenestration.

High Tumoral STMN1 Expression Is Associated with Malignant Potential and Poor Prognosis in Patients with Neuroblastoma.

BACKGROUND: Stathmin 1 (STMN1), a marker for immature neurons and tumors, controls microtubule dynamics by destabilizing tubulin. It plays an essential role in cancer progression and indicates poor prognosis in several cancers. This potential protein has not been clarified in clinical patients with neuroblastoma. Therefore, this study aimed to assess the clinical significance and STMN1 function in neuroblastoma with and without MYCN amplification. METHODS: Using immunohistochemical staining, STMN1 expression was examined in 81 neuroblastoma samples. Functional analysis revealed the association among STMN1 suppression, cellular viability, and endogenous or exogenous MYCN expression in neuroblastoma cell lines. RESULT: High levels of STMN1 expression were associated with malignant potential, proliferation potency, and poor prognosis in neuroblastoma. STMN1 expression was an independent prognostic factor in patients with neuroblastoma. Furthermore, STMN1 knockdown inhibited neuroblastoma cell growth regardless of endogenous and exogenous MYCN overexpression. CONCLUSION: Our data suggest that assessing STMN1 expression in neuroblastoma could be a powerful indicator of prognosis and that STMN1 might be a promising therapeutic candidate against refractory neuroblastoma with and without MYCN amplification.

Association of Psychological Readiness to Return to Sports With Subjective Level of Return at 12 Months After ACL Reconstruction.

Background: Return-to-sports (RTS) rates after anterior cruciate ligament (ACL) reconstruction (ACLR) differ according to the level at which patients return. It is unclear whether the level of RTS is affected by psychological readiness to return. Purpose: To examine the association between psychological readiness to RTS and subjective RTS level 12 months after ACLR. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 47 patients who underwent unilateral primary ACLR surgery were enrolled. Assessments at 6 and 12 months postoperatively consisted of knee strength testing (isokinetic quadriceps and hamstring strength), the International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC-SKF), and the Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scale to measure psychological readiness to RTS. Patients were assigned to 1 of 3 subgroups based on their subjective assessment of RTS level at 12 months postoperatively: RTS at or above preinjury level (RTS≥Pre; n = 19), RTS below preinjury level (RTS

Penile and scrotal strangulation by stainless steel rings in an human immunodeficiency virus positive man: A case report.

BACKGROUND: Penoscrotal constriction devices are either used as autoerotic stimuli or to increase sexual pleasure or performance by maintaining an erection for a longer period, and a variety of metallic and non-metallic objects are used. On the other hand, penile strangulation is a rare urologic emergency that requires prompt evaluation and intervention to prevent long-term complications. The goal of treating penile incarceration is to remove the foreign object as soon as possible. On the other hand, removal can be very challenging, and often requires resourcefulness and a multidisciplinary approach. CASE SUMMARY: A 47-year-old man who has sex with men was transferred to our hospital for persistent phallodynia and scrotal pain, accompanying swelling due to strangulation by stainless steel rings. His medical history included acquired immunodeficiency syndrome. One day prior, he had put three stainless steel rings on his penis and scrotum before sexual intercourse. After sexual intercourse, he was unable to remove them, due to swelling of his penis and scrotum. The swelling persisted, and he felt pain in the affected area the next day, then he was transferred to our hospital by ambulance. The emergency department found that his penis and scrotum were markedly engorged and swollen. We established a diagnosis of penile and scrotal strangulation by stainless steel rings. We unsuccessfully attempted to cut the rings using a cutter, then requested a rescue team via emergency medical service. They cut through each ring in two places, using an electric-powered angle grinder, and successfully removed all of the pieces. Finally, he was discharged and went home. CONCLUSION: We report the first case of penile and scrotal strangulation by stainless steel rings in an human immunodeficiency virus positive person.

Distinct functions between ferrous and ferric iron in lung cancer cell growth.

Accumulating evidence suggests an association between iron metabolism and lung cancer progression. In biological systems, iron is present in either reduced (Fe2+ ; ferrous) or oxidized (Fe3+ ; ferric) states. However, ferrous and ferric iron exhibit distinct chemical and biological properties, the role of ferrous and ferric iron in lung cancer cell growth has not been clearly distinguished. In this study, we manipulated the balance between cellular ferrous and ferric iron status by inducing gene mutations involving the FBXL5-IRP2 axis, a ubiquitin-dependent regulatory system for cellular iron homeostasis, and determined its effects on lung cancer cell growth. FBXL5 depletion (ferrous iron accumulation) was found to suppress lung cancer cell growth, whereas IRP2 depletion (ferric iron accumulation) did not suppress such growth, suggesting that ferrous iron but not ferric iron plays a suppressive role in cell growth. Mechanistically, the depletion of FBXL5 impaired the degradation of the cyclin-dependent kinase inhibitor, p27, resulting in a delay in the cell cycle at the G1/S phase. FBXL5 depletion in lung cancer cells also improved the survival of tumor-bearing mice. Overall, this study highlights the important function of ferrous iron in cell cycle progression and lung cancer cell growth.

Long-term outcome of patients with peripheral ground-glass opacity-dominant lung cancer after sublobar resections.

OBJECTIVE: This study aimed to evaluate the long-term prognosis of patients with peripheral small ground-glass opacity-dominant lung cancer after sublobar resection. We have already reported the 5-year safety and efficacy of sublobar resection and report the long-term outcomes after a 10-year follow-up period. METHODS: Between May 2009 and April 2011, 333 patients with radiologically noninvasive peripheral lung cancer were enrolled from 51 institutions (median age, 62 years at registration) and followed up until May 6, 2021. Of these patients, sublobar resections with wedge resection as the first choice were performed in 314 patients (258 wedge resections and 56 segmentectomies), conversion lobectomies were performed in 11 patients, and 8 patients were ineligible. RESULTS: The 10-year relapse-free survival and overall survival for the 314 patients with sublobar resections were 98.6% (95% confidence interval, 96.2-99.5) and 98.5% (95% confidence interval, 96.1-99.4), respectively. There was 1 local recurrence at the resection margin. Among the patients, second cancers were observed in 43 patients (13.4%; 95% confidence interval, 9.8-17.6), of which 18 were second lung cancers (5.8%; 95% confidence interval, 3.5-8.9). CONCLUSIONS: Peripheral ground-glass opacity-dominant lung cancer is cured by sublobar resection, with wedge resection as the first choice, and the indications for other treatment options should be further investigated. The incidence of second cancer is similar to that in the general Japanese population.

Identification of tumor-related genes via RNA sequencing of tumor tissues in Xenopus tropicalis.

Cancer treatment is still challenging because the disease is often caused by multiple mutations. Although genomic studies have identified many oncogenes and tumor suppressor genes, gene sets involved in tumorigenesis remain poorly understood. Xenopus, a genus of aquatic frogs, is a useful model to identify gene sets because it can be genetically and experimentally analyzed. Here, we analyzed gene expression in tumor tissues of three individuals in Xenopus tropicalis and identified 55 differentially expressed genes (DEGs). Gene ontology (GO) analysis showed that the upregulated genes in the tumor tissues were enriched in GO terms related to the extracellular matrix and collagen fibril organization. Hierarchical clustering showed that the gene expression patterns of tumor tissues in X. tropicalis were comparable to those of human connective, soft, and subcutaneous tissue-derived cancers. Additionally, pathway analysis revealed that these DEGs were associated with multiple pathways, including the extracellular matrix, collagen fibril organization, MET signaling, and keratan sulfate. We also found that the expression tendency of some DEGs that have not been well analyzed in the cancer field clearly determines the prognosis of human cancer patients. This study provides a remarkable reference for future experimental work on X. tropicalis to identify gene sets involved in human cancer.