Tumor formation at ileocecal junction associated with interleukin-1ß upregulation in aryl hydrocarbon receptor-deficient mouse.

Aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor. We previously reported spontaneous ileocecal tumorigenesis in AhR-deficient mice after the age of 10 weeks, which originated in the confined area between ileum and cecum. This study aimed to investigate the underlying mechanism that causes tumor development at this particular location. To observe mucosal architecture in detail, tissues of ileocecal region were stained with methylene blue. Gene expression profile in the ileocecal tissue was compared with cecum. Immunohistochemical analysis was performed with ileocecal tissues using antibodies against ileum-specific Reg3ß or cecum-specific Pitx2. In AhR+/+ mice and AhR+/- mice, that do not develop lesions, methylene blue staining revealed the gradually changing shape and arrangement of villi from ileum to cecum. It was also observed in AhR-deficient mice before developing lesions. Microarray-based analysis revealed abundant antimicrobial genes, such as Reg3, in the ileocecal tissue while FGFR2 and Pitx2 were specific to cecum. Immunohistochemical analysis of AhR-deficient mice indicated that lesions originated from the ileocecal junction, a boundary area between different epithelial types. Site-specific gene expression analysis revealed higher expression of IL-1ß at the ileocecal junction compared with the ileum or cecum of 9-11-week-old AhR-deficient mice. These findings indicate that AhR plays a vital function in the ileocecal junction. Regulating AhR activity can potentially manage the stability of ileocecal tissue possessing cancer-prone characteristics. This investigation contributes to understanding homeostasis in different epithelial transitional tissues, frequently associated with pathological states.

Impacts of tumor microenvironment during neoadjuvant chemotherapy in patients with esophageal squamous cell carcinoma.

With the advent of immune checkpoint inhibitors (ICIs), a better understanding of tumor microenvironment (TME) is becoming crucial in managing esophageal squamous cell carcinoma (ESCC) patients. We investigated the survival impact of TME status and changes in patients with ESCC who underwent neoadjuvant chemotherapy (NAC) followed by surgery (n = 264). We examined immunohistochemical status (CD4+, CD8+, CD20+, Foxp3+, HLA class-1+, CD204+, and programmed death ligand-1 [PD-L1+]) on 264 pre-NAC and 204 paired post-NAC specimens. Patients were classified by their pre- and post-NAC immune cell status and their changes following NAC. Our findings showed that pre-NAC TME status was not significantly associated with survival outcomes. In contrast, post-NAC TME status, such as low level of T cells, CD4+ T cells, and high PD-L1 combined positive score (CPS), were significantly associated with poor overall survival (OS). Notably, TME changes through NAC exerted significant survival impacts; patients with consistently low levels of T cells, low levels of CD4+ T cells, or high levels of PD-L1 (CPS) had very poor OS (3-year OS: 35.5%, 40.2%, and 33.3%, respectively). Tumor microenvironment changes of consistently low T cells, low CD4+ T cells, and high PD-L1 were independent predictors of poor OS in multivariate Cox hazards analyses, while factors indicating post-NAC status (T cells, CD4+, and PD-L1 [CPS]) alone were not. Therefore, we suggest that the consistently low T/high PD-L1 group could benefit from additional therapies, such as ICIs, and the importance of stratification by the TME, which has recently been recognized.

[Chemotherapy and Conversion Surgery for Advanced Gastric Cancer Patient with a Liver Metastasis in 81 Years Old Woman].

Eighty-one year-old woman was pointed out pulmonary tumor by health check and transferred to our hospital. Her performance status was fine. In imaging study, she had advanced gastric cancer with a solitary liver metastasis and highly suspected left lung cancer. She received chemotherapy combined with oxaliplatin and S-1 as first-line. However, the tumor enlarged and then received second-line chemotherapy combined with paclitaxel and ramucirumab. The tumor shrank and a solitary liver metastasis remained. She underwent gastrectomy and partial hepatectomy. After conversion surgery, she had no chemotherapy and had survived over 5 years. Even in old person over 80 years old, chemotherapy and surgery are considerable in patients with well performance status.

Potential involvement of oncostatin M in the immunosuppressive tumor immune microenvironment in hepatocellular carcinoma with vessels encapsulating tumor clusters.

AIM: Vessels encapsulating tumor clusters (VETC) represents an adverse prognostic morphological feature of hepatocellular carcinoma (HCC), which is associated with an immunosuppressive tumor immune microenvironment (TIM). However, the underlying factors characterizing the TIM in HCC with a VETC pattern (VETC-positive HCC) remain uncertain. Oncostatin M (OSM), a pleiotropic cytokine of the interleukin-6 family, regulates various biological processes, including inflammation, proliferation, and invasiveness of tumor cells. We aimed to test a hypothesis that OSM is associated with the immunosuppressive TIM of VETC-positive HCC. METHODS: A total of 397 consecutive HCC patients with curative-intent hepatectomy were included. OSM-positive cells and inflammatory cells including CD4-, CD8-, CD163-, and FOXP3-positive cells were immunohistochemically evaluated. We compared VETC-positive and VETC-negative HCCs in terms of the number of these cells. RESULTS: We found the VETC pattern in 62 patients (15.6%). Our analysis revealed a significant decrease in the expression of arginase-1, a marker associated with mature hepatocyte differentiation, in VETC-positive HCC (p = 0.046). The number of tumor-infiltrating OSM-positive cells was significantly low in VETC-positive HCC (p = 0.0057). Notably, in VETC-positive HCC, the number of OSM-positive cells was not associated with vascular invasion, whereas in VETC-negative HCC, an increase in the number of OSM-positive cells was associated with vascular invasion (p = 0.042). CONCLUSIONS: We identified an association between a decrease in OSM-positive cells and the VETC pattern. Additionally, our findings indicate that VETC-positive HCC is characterized by low hepatocyte differentiation and OSM-independent vascular invasion. These findings highlight the potential interaction between VETC-positive HCC cells and their TIM through the reduction of OSM-expressing cells.

A Case of Immune Thrombocytopenia Occurring after Radiotherapy plus Atezolizumab Treatment for Bladder Cancer.

An 84-year-old female developed gross hematuria. She was diagnosed as urinary bladder carcinoma. She was initiated on concurrent atezolizumab plus radiation(a phase Ⅱ clinical trial)(jRCT2031180060). After 8 cycles of atezolizumab, complete response was confirmed. Maintenance atezolizumab treatment was started. Platelet(Plt)count decreased, there was no rechallenge with atezolizumab. Bone marrow examination revealed normal. Plt count recovered. Plt count decreased again. The serum levels of interleukin-6(IL-6)were elevated. She was diagnosed as having immune thrombocytopenia. She was started on treatment with prednisolone(PSL)at dose of 20 mg/day. Plt count was increased.

Splenic sarcoid reaction mimicking metastases in patients after uterine cancer surgery: a report of two cases.

BACKGROUND: Tumor-associated sarcoid reactions have been observed with various tumors; however, they have not been reported with uterine cancer. We present two cases of splenic sarcoid reactions that mimicked metastases a few years after uterine cancer surgery. CASE PRESENTATION: Case 1 involved a 67-year-old female patient diagnosed with endometrial cancer (pT1aN0M0, pStage Ia, grade 1). The patient underwent open total abdominal hysterectomy and bilateral salpingo-oophorectomy with pelvic lymphadenectomy. Three years after the initial surgery, computed tomography (CT) and positron emission tomography CT showed multiple splenic masses with increasing numbers and sizes. Splenic metastases were diagnosed, and laparoscopic splenectomy was performed. The histopathological analysis revealed sarcoid reactions in the spleen. Case 2 involved a 47-year-old female patient diagnosed with endometrial cancer (pT1aN0M0, pStage Ia, grade 1). The patient underwent laparoscopic total abdominal hysterectomy and bilateral salpingo-oophorectomy with pelvic lymphadenectomy. Two years after the initial surgery, multiple splenic masses were observed. We performed laparoscopic splenectomy for the splenic metastases. Granuloma formations were identified in the splenic specimen and perisplenic lymph nodes that were removed simultaneously, resulting in a final diagnosis of sarcoid reaction. A review of the lymph nodes at the time of the previous uterine surgery revealed granuloma formation. Other than the presence of splenic masses, no findings suggestive of recurrence were observed in these cases. Uterine cancer and sarcoid reactions progressed without recurrence after splenectomy. CONCLUSIONS: To the best of our knowledge, this is the first report of the late development of splenic sarcoid reactions after uterine cancer surgery. Sarcoid reactions and metastases are difficult to diagnose based on preoperative imaging results. However, reviewing the specimen at the time of the initial resection, the number of lesions, and the clinical findings (other than imaging findings) may aid in the determination of the correct diagnosis.

MHC class I loss is associated with biliary/progenitor cell features and "cold" tumor-immune microenvironment in hepatocellular carcinoma.

Hepatocellular carcinomas (HCCs) with biliary/progenitor cell features frequently show increased programmed death-ligand 1 (PD-L1) expression, but their response to immunotherapy is not high. One possible explanation for this phenomenon could be the loss of major histocompatibility complex (MHC) class I expression on tumor cells, which impairs the presentation of tumor antigens to cytotoxic T cells. However, the potential correlation between MHC class I loss, biliary/progenitor cell features, and the tumor-immune microenvironment remains largely unexplored. Herein, we hypothesized that MHC class I loss could be associated with biliary/progenitor cell features and potentially impact the tumor-immune microenvironment. To evaluate this hypothesis and gain insight into the characteristics of tumor cells and the tumor-immune microenvironment in HCCs with MHC class I loss, we examined a consecutive series of 397 HCC cases. MHC class I loss was observed in 32 HCCs (8.1%). Lipid-less cytologic morphology was significantly associated with MHC class I loss (P = 0.02). CK19 expression and decreased ARG1 expression, both known as biliary/progenitor cell features, were significantly associated with MHC class I loss (P < 0.05). PD-L1 expression was irrelevant to the MHC class I status. HCCs with MHC class I loss exhibited significantly lower infiltration of CD8+, CD4+, CD20+, and FOXP3+ cells than those with intact MHC class I (all Ps < 0.01). Our study reveals an association between MHC class I loss, biliary/progenitor cell features, and a "cold" tumor-immune microenvironment in HCCs. These insights highlight the potential impact of MHC class I loss on tumor cells and the tumor-immune microenvironment.

Prognostic Value of Peritoneal Lavage Cytology in Potentially Resectable Pancreatic Cancer Stratified by Cytologic Status.

BACKGROUND/AIM: Patients with pancreatic ductal adenocarcinoma (PDAC) with positive peritoneal lavage cytology (CY) reportedly have poor prognoses. However, the value of diagnosis of suspicious for malignancy on CY is unknown. This study aimed to elucidate the prognostic impact of CY by focusing on CY subgroups. PATIENTS AND METHODS: Data were collected from 231 resectable PDAC patients who underwent curative-intent resection. Patients were divided into three CY-based groups: negative (CY0), suspicious for malignancy (CY-S), and positive (CY1). Clinicopathological characteristics and prognostic factors were analyzed. RESULTS: CY1 and CY-S were diagnosed in 7.8% and 3.9% of the patients, respectively. The CY1 group had significantly larger tumors and higher frequencies of distal tumors, anterior pancreatic tissue invasion, retropancreatic tissue invasion, and R1 resection than the CY0 group. Patient characteristics did not differ between the CY0 and CY-S groups. The CY1 group exhibited worse survival than the CY0 and CY-S groups (median survival time: 18.8 vs. 39.6 months, p=0.0021 and vs. 62.2 months, p=0.018). Multivariate analysis for survival indicated that a tumor size >2 cm, preoperative CA19-9 value >100 U/ml, CY1, lymph node metastasis, R1 resection, and lack of adjuvant chemotherapy were associated with poor prognosis. Both the CY1 and CY-S groups had higher frequencies of peritoneal recurrence than the CY0 group (50% vs. 11.8%, p<0.001 and 44.4% vs. 11.8%, p=0.019). CONCLUSION: The prognosis of the CY1 group was poor. Although CY-S was associated with a higher frequency of peritoneal recurrence than CY0, the long-term outcomes of patients with surgical treatment were acceptable.

Combined tubular adenocarcinoma, neuroendocrine carcinoma and adenocarcinoma with enteroblastic differentiation arising in Barrett esophagus.

Adenocarcinoma (AC) with neuroendocrine carcinoma (NEC) or enteroblastic (ENT) differentiation rarely develops in Barrett's esophagus (BE). A 76-year-old man was diagnosed with Barrett's AC (cT1bN0M0) and underwent thoracoscopic esophagectomy. A type 0-IIc + 0-Is lesion measuring 26 × 21 mm was macroscopically observed on a background of long segment BE (pT1bN0M0). The tumor comprised three different histological types of carcinoma (NEC, AC with ENT differentiation and moderately differentiated AC). NEC showed positivity for synaptophysin, chromogranin A and insulinoma-associated protein 1 with a Ki-67 index of 60.6%. ENT tumors were immunopositive for AFP and sal-like protein 4, and focally immunopositive for human chorionic gonadotrophin. The amounts of NEC, ENT and AC were 40%, 40% and 20%, respectively. p53 expression was positive throughout the tumor. Rb expression was negative at the NEC, but positive at the ENT and AC. CD4 and CD8 densities were lower in the NEC segment than in the AC and ENT segments, and PD-L1 expression was negative throughout the tumor. Early cancer arising in BE with a combination of tubular AC, ENT tumors and NEC is very rare. Our observations might contribute to understanding the carcinogenetic pathways and tumor microenvironment of NEC and ENT tumors.

McKeown esophagectomy for a thoracic esophageal carcinoma patient who has a history of definitive chemoradiotherapy for esophageal carcinoma and total pharyngolaryngectomy for hypopharyngeal cancer.

A 64-year-old man, who had previously undergone definitive chemoradiotherapy (dCRT) and endoscopic resections for metachronous multiple esophageal squamous cell carcinoma (ESCC) and had also received total pharyngolaryngectomy (TPL) for hypopharyngeal cancer, was diagnosed with ESCC in the middle thoracic esophagus (cT3N0M0). Thoracoscopic McKeown esophagectomy was performed for the patient. Although the tumor was tightly adherent to the thoracic duct and both main bronchi, they were successfully mobilized. In order to maintain the blood supply to the trachea, we preserved the bilateral bronchial arteries and avoided prophylactic upper mediastinal lymph node dissection. Cervical end-to-side anastomosis between the jejunum and a gastric conduit was performed. Minor pneumothorax was managed conservatively, and the patient was discharged 44 days after the surgery. Overall, thoracoscopic McKeown esophagectomy was safely performed in a patient with a history of TPL and dCRT. Surgeons should be very careful to prevent tracheobronchial ischemia by optimizing the extent of lymph node dissection.

Development of an osteosarcoma model with MYCN amplification and TP53 mutation in hiPS cell-derived neural crest cells.

Mesenchymal stem cell- or osteoblast-derived osteosarcoma is the most common malignant bone tumor. Its highly metastatic malignant phenotypes, which are often associated with a poor prognosis, have been correlated with the modulation of TP53- and cell-cycle-related pathways. MYC, which regulates the transcription of cell-cycle modulating genes, is used as a representative prognostic marker for osteosarcoma. Another member of the MYC oncoprotein family, MYCN, is highly expressed in a subset of osteosarcoma, however its roles in osteosarcoma have not been fully elucidated. Here, we attempted to create an in vitro tumorigenesis model using hiPSC-derived neural crest cells, which are precursors of mesenchymal stem cells, by overexpressing MYCN on a heterozygous TP53 hotspot mutation (c.733G>A; p.G245S) background. MYCN-expressing TP53 mutated transformed clones were isolated by soft agar colony formation, and administered subcutaneously into the periadrenal adipose tissue of immunodeficient mice, resulting in the development of chondroblastic osteosarcoma. MYCN suppression decreased the proliferation of MYCN-induced osteosarcoma cells, suggesting MYCN as a potential target for a subset of osteosarcoma treatment. Further, comprehensive analysis of gene expression and exome sequencing of MYCN-induced clones indicated osteosarcoma-specific molecular features, such as the activation of TGF-ß signaling and DNA copy number amplification of GLI1. The model of MYCN-expressing chondroblastic osteosarcoma was developed from hiPSC-derived neural crest cells, providing a useful tool for the development of new tumor models using hiPSC-derived progenitor cells with gene modifications and in vitro transformation.

Mechanism of cystogenesis by Cd79a-driven, conditional mTOR activation in developing mouse nephrons.

Polycystic kidney disease (PKD) is a common genetic disorder arising from developmental and postnatal processes. Defects in primary cilia and their signaling (eg, mTOR) underlie the pathogenesis. However, how mTOR regulates tubular integrity remains unclear. The paucity of faithful models has limited our understanding of pathogenesis and, therefore, the refinement of therapeutic targets. To understand the role of mTOR in early cystogenesis, we studied an in-house mouse model, Cd79a-Cre;Tsc1ff. (Cd79a-Tsc1 KO hereafter), recapitulating human autosomal-dominant PKD histology. Cre-mediated Tsc1 depletion driven by the promoter for Cd79a, a known B-cell receptor, activated mTORC1 exclusively along the distal nephron from embryonic day 16 onward. Cysts appeared in the distal nephron at 1 weeks of age and mice developed definite PKD by 4 weeks. Cd79a-Tsc1 KO tubule cells proliferated at a rate comparable to controls after birth but continued to divide even after postnatal day 14 when tubulogenesis is normally completed. Apoptosis occurred only after 9 weeks. During postnatal days 7-11, pre-cystic Cd79a-Tsc1 KO tubule cells showed cilia elongation, aberrant cell intercalation, and mitotic division, suggesting that defective cell planar polarity (PCP) may underlie cystogenesis. mTORC1 was activated in a portion of cyst-lining cells and occasionally even when Tsc1 was not depleted, implying a non-autonomous mechanism. Our results indicate that mTORC1 overactivation in developing distal tubules impairs their postnatal narrowing by disrupting morphogenesis, which orients an actively proliferating cell toward the elongating axis. The interplay between mTOR and cilium signaling, which coordinate cell proliferation with PCP, may be essential for cystogenesis.

Transduodenal ampullectomy for early ampullary cancer: Clinical management, histopathological findings and long-term outcomes at a single center.

BACKGROUND: Transduodenal ampullectomy has been attempted in ampullary tumors, including early ampullary cancer. However, the indication and extent of transduodenal ampullectomy with curative intent remain controversial. Herein, we address the perioperative and long-term outcomes of patients with early ampullary cancer who underwent transduodenal ampullectomy at a single center. METHODS: We retrospectively enrolled 10 early ampullary cancer patients who underwent transduodenal ampullectomy and 11 early ampullary cancer patients who underwent subtotal stomach-preserving pancreatoduodenectomy at Saitama Cancer Center between October 2008 and May 2021. Among this cohort, we analyzed the perioperative outcomes and long-term outcomes. RESULTS: In terms of the perioperative outcomes between the transduodenal ampullectomy and subtotal stomach-preserving pancreatoduodenectomy groups, the transduodenal ampullectomy group exhibited a shorter operating time (244 minutes vs 390 minutes, P = .003), less intraoperative blood loss (67.5 grams vs 774 grams, P = .006) and shorter length of postoperative hospital stay (15 days vs 33 days). With respect to the postoperative nutrition status, the transduodenal ampullectomy group exhibited less postoperative weight loss (0.67% vs 8.95%, P = .021), a better Controlling Nutritional Status score (1.0 vs 2.1, P = .011) and a better Prognostic Nutritional Index score (42.9 vs 40.9, P = .018). The 5-year survival in the adenoma with high-grade dysplasia and T1 ampullary cancer which invaded the mucosal layer groups was 100%, whereas the median survival time in the T1 ampullary cancer which invaded the sphincter of Oddi group was 20.7 months (P = .0028). CONCLUSION: Transduodenal ampullectomy is assumed to be a feasible and effective surgical procedure for the treatment of selected patients with early ampullary cancer, including patients with adenoma with high-grade dysplasia or T1 ampullary cancer which invaded the mucosal layer ampullary cancer.

Stiffness as measured with strain elastography is a prognostic factor for pT1/T2 tongue squamous cell carcinoma with muscle-layer invasion.

OBJECTIVE: The objective was to evaluate stiffness as a prognostic factor for tongue squamous cell carcinoma (TSCC). STUDY DESIGN: This retrospective study included 55 patients with pathologic stage pT1 or T2 TSCC with muscle-layer invasion who underwent preoperative strain elastography of the tongue, followed by surgery, as the primary treatment modality at our cancer center. The stiffness of TSCC was semi-quantified as the ratio of the strain value of a non-tumor site to the strain value of the tumor site (strain ratio [SR]) using ultrasound strain elastography findings. RESULTS: SR cutoff values that maximized the significance of the difference for prognosis of delayed cervical lymph node metastasis (DCLNM) and overall survival (OS) were 7.10 and 7.49, respectively. In univariate analysis, SR, age, depth of invasion, pT stage, and perineural invasion were significant risk factors for DCLNM, whereas SR, sex, and DCLNM were identified as having an association with OS. In multivariate analysis, SR was a significant risk factor for DCLNM (hazard ratio [HR] = 3.102; P = .021) and a non-significant but relevant risk factor for OS (HR = 8.774; P = .073). Age also had an association with OS (HR = 0.382; 95% CI 0.127-1.152; P = .088). CONCLUSION: Tongue stiffness is a prognostic factor in patients with pT1/T2 TSCC with muscle-layer invasion. SR values >7.10 indicate a poor prognosis, thereby warranting a strict follow-up regimen in these cases.

Influences of intratumoral heterogeneity on assessment of tumor microenvironment in esophageal squamous cell carcinoma.

The intratumoral heterogeneity (ITH) of the tumor microenvironment (TME) has yet to be addressed in esophageal squamous cell carcinoma (ESCC). Here, we studied the ITH of CD8 and PD-L1 status in ESCC, and examined the potential of the tumor surface for representing the TME. In total, 67 surgically resected clinical Stage II ESCC specimens were analyzed. The CD8-cell density, PD-L1 tumor proportion score (TPS), and combined positive score (CPS) were calculated in three (superficial, middle, and deep) areas of each specimen. ITH was quantified by distance-standardized coefficient variations of the three values. The CD8 and PD-L1 status of each area was dichotomized and tumor-surface capabilities for predicting the entire tumor status were estimated. Variables were compared according to the presence of neoadjuvant chemotherapy (NAC). The ITH, especially PD-L1 heterogeneity, differed markedly among specimens. The concordance rates of CD8 and PD-L1 (CPS and TPS) status among the three different areas were 71.6%, 74.6%, and 73.1%, respectively. The sensitivity and the specificity of the tumor surface for predicting the CD8 status of the whole tumor were high, especially in the NAC- group (both 1.0). The tumor surface also showed high capabilities for representing the whole PD-L1 status, while yielding moderate positive predictive values (0.70). The ITH degrees and predictive capabilities did not differ according to NAC. Taken together, the ITH of CD8 and PD-L1 differed among ESCC specimens, while not being markedly affected by NAC. The use of a biopsy specimen from the tumor surface might be feasible for TME evaluation.

Perivascular epithelioid cell tumor (PEComa) of the cystic duct.

Perivascular epithelioid cell tumors, also known as PEComas, are rare mesenchymal tumors composed mainly of epithelioid cells found in perivascular tissue. PEComas occur most frequently in the kidney, uterus, the gastrointestinal tract, liver, and retroperitoneum; those originating in the biliary tree are extremely rare. We report a case of benign PEComa of the cystic duct with positive TFE3 staining on immunohistochemistry.A 66-year-old woman was referred for a 20 mm mass adjacent to the common bile duct discovered incidentally on abdominal ultrasound. Laboratory data including tumor markers were unremarkable. The tumor appeared to arise from the cystic duct, showed early enhancement, and compressed the common bile duct on imaging studies. Endoscopic ultrasound-guided fine-needle aspiration revealed round- and spindle-shaped atypical cells with eosinophilic cytoplasm and brown deposits suggestive of melanin granules. Histological examination of the resected specimen revealed a tumor consisting of epithelioid cells forming an alveolar structure, with melanin pigmentation. Immunohistochemistry was positive for HMB-45 and TFE3, consistent with benign pigmented PEComa of the cystic duct. Melanotic, myogenic, and TFE3 staining are helpful when diagnosing PEComas arising in unusual locations.

A Case of Diffuse Large B-Cell Lymphoma Complicated by Helicobacter Pylori-Negative Russell Body Gastritis.

A 76-year-old woman with a past history of diabetes mellitus and Hashimoto's disease, in regard to her personal history, she did not smoke or drink alcohol. In March, year X-1, she became aware of cervical lymphadenopathy. Based on the findings of lymph node biopsy, she was diagnosed as having diffuse large B-cell lymphoma(DLBCL). An upper gastrointestinal endoscopy(U-GIE)revealed white granular prominences in the gastric fornix, and biopsy of these lesions revealed the diagnosis of Russell body gastritis(RBG). Neither lymphoma infiltration nor other malignant findings were found. Diagnostic tests for Helicobacter pylori were negative. The clinical stage of the DLBCL was determined as stage ⅢA, and the International Prognostic Index was"high intermediate". She received 6 cycles of R-CHOP therapy, with concomitant use of a proton pump inhibitor. Complete remission was confirmed in November, year X-1. An U-GIE performed again no longer showed the white granular prominences in the gastric fornix. The present report is the first of DLBCL complicated by RBG; our findings suggested that the two diseases were associated with each other.

GLS2 Is a Tumor Suppressor and a Regulator of Ferroptosis in Hepatocellular Carcinoma.

Glutamine synthase 2 (GLS2) is a key regulator of glutaminolysis and has been previously implicated in activities consistent with tumor suppression. Here we generated Gls2 knockout (KO) mice that develop late-occurring B-cell lymphomas and hepatocellular carcinomas (HCC). Further, Gls2 KO mice subjected to the hepatocarcinogenic Stelic Animal Model (STAM) protocol produce larger HCC tumors than seen in wild-type (WT) mice. GLS2 has been shown to promote ferroptosis, a form of cell death characterized by iron-dependent accumulation of lipid peroxides. In line with this, GLS2 deficiency, either in cells derived from Gls2 KO mice or in human cancer cells depleted of GLS2, conferred significant resistance to ferroptosis. Mechanistically, GLS2, but not GLS1, increased lipid reactive oxygen species (ROS) production by facilitating the conversion of glutamate to α-ketoglutarate (αKG), thereby promoting ferroptosis. Ectopic expression of WT GLS2 in a human hepatic adenocarcinoma xenograft model significantly reduced tumor size; this effect was nullified by either expressing a catalytically inactive form of GLS2 or by blocking ferroptosis. Furthermore, analysis of cancer patient datasets supported a role for GLS2-mediated regulation of ferroptosis in human tumor suppression. These data suggest that GLS2 is a bona fide tumor suppressor and that its ability to favor ferroptosis by regulating glutaminolysis contributes to its tumor suppressive function. SIGNIFICANCE: This study demonstrates that the key regulator of glutaminolysis, GLS2, can limit HCC in vivo by promoting ferroptosis through αKG-dependent lipid ROS, which in turn might lay the foundation for a novel therapeutic approach.