Tumor-derived semaphorin 3D promoting cancer cachexia via regulating hypothalamic pro-opiomelanocortin neurons.

Cachexia is very common in cancer patients and predicts a poor prognosis; however, the molecular basis for progress in these individuals remains unclear, especially the effect of tumors on the hypothalamus energy regulation center. To investigate the regulatory pathway of tumors associated with hypothalamic pro-opiomelanocortin (POMC) neurons known as appetite-inhibiting neurons, we conducted observations both on patients and mice models. Results showed that the highly expressed exocrine semaphorin 3D (SEMA3D) both in cachexia patients and mice was positively related to the expression of POMC and its proteolytic peptide. Compared with the control group, mice inoculated with the SEMA3D-knockout C26 cell line decreased the activity of POMC neurons resulting in a 1.3-fold increase in food intake, a 22.2% increase in body weight, and reduced skeletal muscle and fat catabolism. The effect of SEMA3D on cachexia progression can be partially alleviated by knocking-down POMC expression in the brain. In terms of mechanism, SEMA3D enhances the activity of POMC neurons by activating the expression of NRP2 (membrane receptor) and PlxnD1 (intracellular receptor). Our research revealed the overexpression of SEMA3D in tumors works as an activator of POMC neurons, which may play a vital role in suppressing appetite and promoting catabolic metabolism.

Decoding PTEN: from biological functions to signaling pathways in tumors.

The tumor suppressor gene Phosphatase and tensin homologue deleted on chromosome 10 (PTEN), possessing both protein and lipid phosphatase activities, is frequently mutated in various human cancers. PTEN aberrations disrupt critical cellular processes like proliferation, apoptosis, migration, and invasion, thereby promoting tumor growth. In the cells, PTEN localizes to the nucleus, cytoplasm, or cell membrane, and its roles depends on the subcellular localization. PTEN is regulated at the transcriptional, post-transcriptional, and post-translational levels, implying that its functions on the tumors are complex. The relationship between PTEN abnormalities and tumors has garnered significant interest in recent years. PTEN regulates essential cellular processes involved in tumorigenesis. Mutations or deletions in the PTEN gene often correlate with unfavorable prognosis and increased cancer recurrence. Numerous studies suggest that PTEN expression levels in tumors could be a valuable biomarker for cancer diagnosis, treatment, and predicting patient outcomes. This paper provides a comprehensive review of the biological function, regulatory mechanisms, and post-translational modifications of PTEN. Furthermore, this review explores the expression and regulation of PTEN in different tumor types, as well as its interactions with environmental factors in tumorigenesis. This comprehensive analysis aims to deepen our understanding of the signaling pathways between PTEN and cancer.

Low expression of ELOVL6 may be involved in fat loss in white adipose tissue of cancer-associated cachexia.

BACKGROUND: Cancer-associated cachexia (CAC) arises from malignant tumors and leads to a debilitating wasting syndrome. In the pathophysiology of CAC, the depletion of fat plays an important role. The mechanisms of CAC-induced fat loss include the enhancement of lipolysis, inhibition of lipogenesis, and browning of white adipose tissue (WAT). However, few lipid-metabolic enzymes have been reported to be involved in CAC. This study hypothesized that ELOVL6, a critical enzyme for the elongation of fatty acids, may be involved in fat loss in CAC. METHODS: Transcriptome sequencing technology was used to identify CAC-related genes in the WAT of a CAC rodent model. Then, the expression level of ELOVL6 and the fatty acid composition were analyzed in a large clinical sample. Elovl6 was knocked down by siRNA in 3T3-L1 mouse preadipocytes to compare with wild-type 3T3-L1 cells treated with tumor cell conditioned medium. RESULTS: In the WAT of patients with CAC, a significant decrease in the expression of ELOVL6 was found, which was linearly correlated with the extent of body mass reduction. Gas chromatographic analysis revealed an increase in palmitic acid (C16:0) and a decrease in linoleic acid (C18:2n-6) in these tissue samples. After treatment with tumor cell-conditioned medium, 3T3-L1 mouse preadipocytes showed a decrease in Elovl6 expression, and Elovl6-knockdown cells exhibited a reduction in preadipocyte differentiation and lipogenesis. Similarly, the knockdown of Elovl6 in 3T3-L1 cells resulted in a significant increase in palmitic acid (C16:0) and a marked decrease in oleic acid (C18:1n-9) content. CONCLUSION: Overall, the expression of ELOVL6 was decreased in the WAT of CAC patients. Decreased expression of ELOVL6 might induce fat loss in CAC patients by potentially altering the fatty acid composition of adipocytes. These findings suggest that ELOVL6 may be used as a valuable biomarker for the early diagnosis of CAC and may hold promise as a target for future therapies.

Total intracorporeal laparoscopic ileal ureter replacement in a single position for ureteral stricture based on membrane anatomy.

PURPOSE: The aim of this study was to present our initial experience and prove the feasibility of total intracorporeal laparoscopic ileal ureter replacement (TILIUR) in a single position for ureteral stricture based on membrane anatomy. MATERIALS AND METHODS: Between January 2021 and April 2023, six patients underwent TILIUR in a single position for ureteral strictures based on membrane anatomy. All patients with a past medical history underwent radical hysterectomy with bilateral pelvic lymph node dissection as well as extensive ureteral stricture due to radiotherapy. The procedure is performed completely laparoscopically. Dissection of the digestive system as well as ureteral stricture or renal pelvis is based on membrane anatomy. The surgery is performed in a single position. RESULTS: TILIUR in a single position for ureteral stricture based on membrane anatomy was successfully performed without open conversion in all patients. Among the 6 patients, 3 patients underwent combined ileal ureter replacement (IUR) and abdominal wall ostomy, 2 underwent unilateral IUR, and 1 underwent bilateral IUR. The mean length of the ileal substitution was 22.83 cm (range: 15-28). The average operative time was 458 ± 72.77 min (range 385-575 min), and the average intraoperative blood loss was 158 mL (range 50-400 mL). The median postoperative hospital stay was 15.1 d (range: 8-32). The median duration of postoperative follow-up was 15 months (range: 3-29 months). The success rate was 100%. CONCLUSIONS: TILIUR in a single position may be a promising option for ureteral stricture based on membrane anatomy in selected patients. Moreover, it has a positive effect on patients with renal insufficiency and urinary incontinence. Although IUR is difficult and risky, proficient surgeons can perform the procedure safely and effectively.

Sarcopenia and myosteatosis diagnostic tool for gastrointestinal cancer: creatinine to cystatin C ratio as evaluation marker.

OBJECTIVE: This study aimed to develop a simplified diagnostic tool for assessing sarcopenia and myosteatosis in gastrointestinal cancer patients, focusing on the creatinine to cystatin C ratio (CCR) as an evaluation marker. METHODS: 955 patients were split into training (n = 671) and validation (n = 284) cohorts. Using logistic regression, risk factors for sarcopenia and myosteatosis were identified. The predictive capacity of the developed model was examined. The association between CCR and muscle imaging parameters, along with its impact on clinical outcomes, was analyzed. RESULTS: No significant differences were observed in baseline traits between cohorts. CCR emerged as a significant risk factor for both sarcopenia and myosteatosis. Nomograms for diagnosing these conditions demonstrated strong predictive ability, with AUC values indicating high accuracy (sarcopenia AUC: 0.865-0.872; myosteatosis AUC: 0.848-0.849). The clinical utility of the nomograms was confirmed through decision curve analysis. CCR showed significant association with muscle imaging parameters and was a reliable indicator for assessing the risk of sarcopenia, myosteatosis, and cachexia. Moreover, CCR was able to differentiate between patient survival and disease progression rates. CONCLUSION: A diagnostic tool for sarcopenia and myosteatosis in gastrointestinal cancer patients was developed, with CCR being a pivotal biomarker for disease diagnosis and prognosis prediction.

Unraveling the gut microbiota and short-chain fatty acids characteristics and associations in a cancer cachexia mouse model.

OBJECTIVE: Cachexia is a common pathological condition in cancer patients, affecting prognosis and treatment outcomes. The relationship between cachexia and gut microbiota and short-chain fatty acids (SCFAs) remains understudied. This research aimed to establish a cachexia mouse model and explore the gut microbiota-SCFAs connection. The study provides fundamental insights into the regulatory mechanisms of cancer cachexia and potential therapeutic strategies. METHODS: A cachexia mouse model was created using C26 cells, with relevant indicators measured. Histological and immunohistochemical analyses assessed muscle structure and protein expression. ELISA was performed to detect the levels of IL-1ß, IL-6, TNF-α, and LPS in serum to evaluate inflammation.16S rDNA sequencing and GC-MS quantified gut microbiota and SCFAs. Bioinformatics analysis identified indicator species and explored microbiota-SCFAs correlations.ROC analysis was performed to assess the potential of gut microbiota and SCFAs in identifying cachexia. RESULTS: The cachexia mouse model exhibited weight loss, muscle atrophy, and elevated inflammatory factors. Gut microbiota in cachexia mice showed decreased diversity and imbalance. Fourteen bacterial genera were identified as potential cachexia indicators. Functional prediction indicated alterations in the functional composition of gut microbial communities in cachexia mice, particularly in carbohydrate and lipid metabolism pathways. Four SCFAs showed significant changes, potentially serving as diagnostic factors. Specific microbial taxa were positively or negatively correlated with changes in SCFAs, and these microbial taxa and differential SCFAs were also correlated with inflammatory cytokines. CONCLUSION: Our study uncovers the gut microbiota and SCFAs features in a cachexia mouse model, revealing novel correlations between them. These newfound insights into the interplay between cachexia, gut microbiota, and SCFAs provide a crucial foundation for understanding the mechanisms behind cancer cachexia development and potential therapeutic approaches.

Abdominal fat and muscle distributions in different stages of colorectal cancer.

BACKGROUND: The purpose of this study is to explore the difference of abdominal fat and muscle composition, especially subcutaneous and visceral adipose tissue, in different stages of colorectal cancer (CRC). MATERIALS AND METHODS: Patients were divided into 4 groups: healthy controls (patients without colorectal polyp), polyp group (patients with colorectal polyp), cancer group (CRC patients without cachexia), and cachexia group (CRC patients with cachexia). Skeletal muscle (SM), subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), and intermuscular adipose tissue (IMAT) were assessed at the third lumbar level on computed tomography images obtained within 30 days before colonoscopy or surgery. One-way ANOVA and linear regression were used to analyze the difference of abdominal fat and muscle composition in different stages of CRC. RESULTS: A total of 1513 patients were divided into healthy controls, polyp group, cancer group, and cachexia group, respectively. In the development of CRC from normal mucosa to polyp and cancer, the VAT area of the polyp group was significantly higher than that of the healthy controls both in male (156.32 ± 69.71 cm2 vs. 141.97 ± 79.40 cm2, P = 0.014) and female patients (108.69 ± 53.95 cm2 vs. 96.28 ± 46.70 cm2, P = 0.044). However, no significant differences were observed of SAT area between polyp group and healthy controls in both sexes. SAT area decreased significantly in the male cancer group compared with the polyp group (111.16 ± 46.98 cm2 vs. 126.40 ± 43.52 cm2, P = 0.001), while no such change was observed in female patients. When compared with healthy controls, the SM, IMAT, SAT, and VAT areas of cachexia group was significantly decreased by 9.25 cm2 (95% CI: 5.39-13.11 cm2, P < 0.001), 1.93 cm2 (95% CI: 0.54-3.32 cm2, P = 0.001), 28.84 cm2 (95% CI: 17.84-39.83 cm2, P < 0.001), and 31.31 cm2 (95% CI: 18.12-44.51 cm2, P < 0.001) after adjusting for age and gender. CONCLUSION: Abdominal fat and muscle composition, especially SAT and VAT, was differently distributed in different stages of CRC. It is necessary to pay attention to the different roles of subcutaneous and visceral adipose tissue in the development of CRC.

Nerve-Sparing Laparoscopic Cystoprostatectomy Based on Inferior Hypogastric Plexus Dissection: Our Initial Experience.

INTRODUCTION: The aim of this study was to implement our technique for the initial dissection of the inferior hypogastric plexus and protection of the autonomic nerve supply to the corpora cavernosa in laparoscopic radical cystoprostatectomy with an orthotopic ileal neobladder and report the initial outcomes. METHODS: Eleven normally potent patients with preoperative cT2N0 bladder cancer who underwent bilateral nerve-sparing laparoscopic cystoprostatectomy performed by the same surgeon were selected from May 2018 to September 2020. In this procedure, the anterior part of the inferior hypogastric plexus was dissected first between the prehypogastric nerve fascia and rectal proper fascia medial to the distal ureter. Then the Denonvilliers' fascia and the nerves around the prostate were preserved according to current intrafascial principles. The preliminary operative, oncologic, and functional results are presented. RESULTS: The median follow-up duration was 18 months. We observed early and late complications in 5 patients, but none exceeded grade III. Of the 11 patients, ten gained daytime continence (90.9%), and 8 (72.7%) showed nocturnal continence at the last follow-up. Regarding postoperative potency, 10 of the 11 patients (90.9%) remained potent with or without oral medications, excluding one who had partial tumescence but did not follow our recommendations regarding medication use. No local recurrence or positive surgical margins were noted. CONCLUSION: In addition to emphasizing our cavernosal nerve-sparing procedure, this report on the precise dissection and protection of the inferior hypogastric plexus could be of clinical significance, providing potentially ideal short-term functional results.

AKG induces cell apoptosis by inducing reactive oxygen species-mediated endoplasmic reticulum stress and by suppressing PI3K/AKT/mTOR-mediated autophagy in renal cell carcinoma.

BACKGROUND: Alpha-ketoglutarate (AKG) or 2-oxoglutarate is a key substance in the tricarboxylic acid cycle (TCA) and has been known to play an important role in cancerogenesis and tumor progression. Renal cell carcinoma (RCC) is the most common type of kidney cancer, and it has a high mortality rate. Autophagy is a phenomenon of self-digestion, and its significance in tumor genesis and progression remains debatable. However, the mechanisms underlying how AKG regulates autophagy in RCC remain unknown. Thus, the purpose of this study was to assess the therapeutic efficacy of AKG and its molecular mechanisms. METHODS: RCC cell lines 786O and ACHN were treated with varying doses of AKG for 24 h. CCK-8, Transwell, and scratch wound healing assays were utilized to evaluate the role of AKG in RCC cells. Autophagy protein and PI3K/AKT/mTOR pathway protein levels were analyzed by Western blot. RESULTS: AKG inhibited the proliferation of RCC cells 786O and ACHN in a dose-dependent manner according to the CCK-8 assay. In addition, flow cytometry and Western blot analysis revealed that AKG dose-dependently triggered apoptosis and autophagy in RCC cells. By promoting cell apoptosis and autophagy, AKG dramatically suppressed tumor growth. Mechanistically, AKG induces autophagy by promoting ROS generation and inhibiting the PI3K/AKT/mTOR pathway. CONCLUSIONS: The anti-tumor effect of AKG promotes autophagy in renal cancer cells via mediating ROS-PI3K/Akt/mTOR, and may be used as a potential anticancer drug for kidney cancer.

Mitophagy-mediated inflammation and oxidative stress contribute to muscle wasting in cancer cachexia.

Cancer cachexia is commonly seen in patients with malignant tumors, which usually leads to poor life quality and negatively affects long-term prognosis and survival. Mitochondria dysfunction and enhanced autophagy are well-established to play an important role in skeletal muscle wasting. However, whether mitophagy is engaged in the pathogenesis of cancer cachexia requires further investigation. This study comprised a clinical study and animal experimentation. Clinical data such as CT images and laboratory results were obtained and analyzed. Then mice model of cancer cachexia and mitophagy inhibition were established. Data including skeletal muscle mass and function, mitochondria structure and function, inflammatory factors as well as ROS concentration. Mitophagy was enhanced in cancer cachexia patients with increased inflammatory factors. Greater disruption of skeletal muscle fiber and mitochondria structure were seen in cancer cachexia, with a higher level of inflammatory factors and ROS expression in skeletal muscle. Meanwhile, ATP production was undermined, indicating a close relationship with mitophagy, inflammation, and oxidative stress in the skeletal muscle of cancer cachexia mice models. In conclusion, mitophagy is activated in cancer cachexia and may play a role in skeletal muscle atrophy, and inflammation and oxidative stress might participate in mitophagy-related skeletal muscle injury.

Initial Experience with the Comprehensive Modified Laparoscopic Pyeloplasty Technique Based on Membrane Anatomy for Treating Ureteropelvic Junction Obstruction.

OBJECTIVE: The aim of the objective was to present our initial experience and evaluate the feasibility of the novel comprehensive modified laparoscopic pyeloplasty (CMLP) technique based on membrane anatomy. MATERIALS AND METHODS: Forty-eight patients underwent CMLP from February 2016 to October 2020. CMLP involves the following: dissection of the ureter was based on the fascia or fusion fascia formed by embryonic development. The ureter was separated from the ureteral sheath, and the pelvis and ureter were incised with incomplete amputation. The first stitch was placed between the lower point of the spatulated ureter and the lowest corner of the renal pelvis to ensure correct orientation of the anastomosis; anastomosis of the renal pelvis and ureter was performed using the touchless technique. RESULTS: All CMLPs were completed successfully without conversion. The mean overall operating time was 230.96 min. The median estimated blood loss was 50.00 (interquartile range 20.00-57.50) mL. The average postoperative hospital stay was 9.31 days. The average follow-up time was 24.73 months. No major complications occurred. In 1 case, revision laparoscopic pyeloplasty was performed, but the obstruction persisted after double J stent removal, so ultimately, the double J stent required regular replacement. Another asymptomatic patient with hydronephrosis experienced failed treatment and is still under follow-up. The overall success rate was 95.83% (46/48). The success rate in patients with recurrent ureteropelvic junction obstruction (UPJO) was 87.5% (7/8). CONCLUSIONS: CMLP is a practical and effective treatment option for UPJO with a high success rate. An advantage of CMLP is the clear surgical field.

Oral nutritional supplements, physical activity, and sarcopenia in cancer.

PURPOSE OF REVIEW: Sarcopenia is prevalent in cancer patients and can occur as a result of cancer as well as cancer-related therapies. It is related to high postoperative complications, long hospitalization, slow recovery as well as low tolerance to chemotherapy. Patients with sarcopenia also have poor oncological outcomes. Oral nutritional supplements (ONS) and physical activity have shown great potentials in managing this debilitating condition. We summarized the recent developments in the assessment of sarcopenia and its management with ONS and physical activity. RECENT FINDINGS: Many methods were developed to evaluate sarcopenia including muscle quality/quantity measurement and functional tests. Recent studies have shown that ONS and physical training can be used in managing sarcopenia, especially when used together as part of a multimodal intervention. However, barriers such as low awareness and lack of training and support for both patients and healthcare workers still exist and need attention. SUMMARY: Recent findings highlighted the benefits of identifying sarcopenia and managing those at risk. The details of a multimodal protocol, such as components of nutritional substrates, the intensity of physical exercise, and the use of medication need to be further looked into for an optimum approach. Education and training programs need to be developed to overcome the barriers in managing sarcopenia.

miR-410-3P inhibits adipocyte differentiation by targeting IRS-1 in cancer-associated cachexia patients.

BACKGROUNDS: Cancer-associated cachexia (CAC) is a metabolic syndrome characterized by progressive depletion of adipose and muscle tissue that cannot be corrected by conventional nutritional therapy. Adipose tissue, an important form of energy storage, exhibits marked loss in the early stages of CAC, which affects quality of life and efficacy of chemotherapy. MicroRNAs (miRNAs) are a class of noncoding RNAs that widely exist in all kinds of eukaryotic cells and play regulatory roles in various biological processes. However, the role of miRNAs in adipose metabolism in CAC has rarely been reported. This study attempted to identify important miRNAs in adipose metabolism in CAC and explore their mechanism to identify a new predictive marker or therapeutic target for CAC-related adipose tissue loss (CAL). METHODS: In this study, miRNA sequencing was firstly used to identify differentially expressed miRNAs related to CAL and the reliability of the conclusions was verified in large population samples. Furthermore, functional experiments were performed by up and down regulating miR-410-3p in adipocytes. The binding of miR-410-3p to Insulin Receptor Substrate 1 (IRS-1) was verified by Luciferase reporter assay and functional experiments of IRS-1 were performed in adipocytes. Finally, the expression of miR-410-3p in serum exosomes was detected. RESULTS: miR-410-3p was selected as differentially expressed miRNA through screening and validation. Adipogenesis was suppressed in miR-410-3p upregulation experiment and increased in downregulation experiment. Luciferase reporter assay showed that miR-410-3p binds to 3' non-coding region of IRS-1 and represses its expression and ultimately inhibits adipogenesis. miR-410-3p was highly expressed in serum exosomes of CAC patients, which was consistent with results in adipose tissue. CONCLUSIONS: The expression of miR-410-3p was higher in subcutaneous adipose tissues and serum exosomes of CAC patients, which significantly inhibits adipogenesis and lipid accumulation. The study shows that miR-410-3p could downregulate IRS-1 and downstream adipose differentiation factors including C/EBP-a and PPAR-γ by targeting 3' noncoding region.

Nutrition and exercise prehabilitation in elderly patients undergoing cancer surgery.

Surgical resection is the primary and most effective treatment for cancer patients. While such a traumatic intervention often accompanies different degrees of postoperative risk largely depending on the patient's health status. Due to the high prevalence of malnutrition or low cardiorespiratory fitness in elderly cancer patients, prehabilitation is an optimal program to reduce postoperative complications and enhance recovery from surgical trauma. An increasing body of evidence suggests that improving nutrition and taking aerobic exercise or strength training prior to major surgery can help reduce postoperative morbidity, mortality, or length of stay. However, there are still controversies regarding the manner, intensity, or duration of preoperative nutrition and exercise training in elderly patients, as well as the impact on delaying cancer treatment. This article reviews the impact of prehabilitation on improving postoperative outcomes in the multi-modal or single-modal pathway, aiming to maximize its effectiveness and increase medical practitioners' attention on enhancing the physical condition of the elderly cancer patients preoperatively.

Silencing of circFoxO3 Protects HT22 Cells from Glutamate-Induced Oxidative Injury via Regulating the Mitochondrial Apoptosis Pathway.

Recent studies demonstrated that FoxO3 circular RNA (circFoxO3) plays an important regulatory role in tumourigenesis and cardiomyopathy. However, the role of circFoxO3 in neurodegenerative diseases remains unknown. The aim of this study was to examine the possible role of circFoxO3 in neurodegenerative diseases and the underlying mechanisms. To model human neurodegenerative conditions, hippocampus-derived neurons were treated with glutamate. Using molecular and cellular biology approaches, we found that circFoxO3 expression was significantly higher in the glutamate treatment group than that in the control group. Furthermore, silencing of circFoxO3 protected HT22 cells from glutamate-induced oxidative injury through the inhibition of the mitochondrial apoptotic pathway. Collectively, our study demonstrates that endogenous circFoxO3 plays a key role in inducing apoptosis and neuronal cell death and may act as a novel therapeutic target for neurodegenerative diseases.

Cachexia-related long noncoding RNA, CAAlnc1, suppresses adipogenesis by blocking the binding of HuR to adipogenic transcription factor mRNAs.

Cancer-associated cachexia (CAC) is a devastating syndrome characterized by progressive losses of adipose tissue and skeletal muscle. CAC-related adipose tissue loss (CAL) occurs early and is associated with a shorter survival time. To explore potential regulatory long noncoding RNAs (lncRNAs) of CAL, RNA microarrays were used to analyze the transcriptomes of white adipose tissue from CAC mice vs. control mice. A set of differentially expressed lncRNAs was identified, and among them was CAAlnc1, which suppressed adipogenesis of C3H10 cells as demonstrated by gain-of-function and loss-of-function experiments. RNA immunoprecipitation and pull-down assays revealed Hu antigen R (HuR) was an important binding partner of CAAlnc1. The interaction between CAAlnc1 and HuR blocked the binding of HuR to adipogenic transcription factor mRNAs and further downregulated the expression of these transcription factors. This study generated a list of CAL-related lncRNAs and provided details of a functional lncRNA which may play an important role in CAL.

U2-related proteins CHERP and SR140 contribute to colorectal tumorigenesis via alternative splicing regulation.

Dysregulation of calcium homeostasis endoplasmic reticulum protein (CHERP) has been implicated in several cancers, but it remains elusive how CHERP contributes to cancer cell proliferation and cancer development. Here, we observed that CHERP and its binding partner SR140 are significantly upregulated in human clinical colorectal cancer tissues (CRC). CHERP and SR140 could form a protein complex to stabilize each other. Knockdown of CHERP or SR140 triggers double-stranded DNA breaks and cell death. Furthermore, UPF3A, the RNA surveillance factor, was identified as a splicing target of CHERP and SR140, which bind specifically to the regulated exon4 and modulate UPF3A splicing. UPF3A knockdown recapitulates CHERP/SR140 depletion both in vitro and in mice. Importantly, overexpression of UPF3A significantly rescues proliferation defect of CHERP/SR140-depleted cells. These results confirmed that the effect of CHERP/SR140 in promoting tumorigenesis was partially mediated by UPF3A. Extending these results, upregulation of CHERP/SR140 observed in CRC remarkably parallels increased inclusion of UPF3A exon4. Together, our study clarifies how CHERP/SR140 exert an oncogenic role in CRC development partially through regulating expression of UPF3A variants.

Interleukin-6 induces fat loss in cancer cachexia by promoting white adipose tissue lipolysis and browning.

BACKGROUND: Cancer cachexia is a progressive and multi-factorial metabolic syndrome characterized by loss of adipose tissue and skeletal muscle. White adipose tissue (WAT) lipolysis and white-to-brown transdifferentiation of WAT (WAT browning) are proposed to contribute to WAT atrophy in cancer cachexia. Chronic inflammation, mediated by cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), has been reported to promote cancer cachexia. However, whether chronic inflammation promotes cancer cachexia by regulating WAT metabolism and the underlying mechanism remains unclear. METHODS: In this study, we first analyzed the association between chronic inflammation and WAT metabolism in gastric and colorectal cancer cachectic patients. In cachectic mice treated with anti-IL-6 receptor antibody, we clarified whether WAT lipolysis and browning were regulated by IL-6. RESULTS: Clinical analyses showed positive significant association between serum IL-6 and free fatty acid (FFA) both in early- and late-stage cancer cachexia. However, serum TNF-α was positively associated with serum FFA in the early- but not late-stage cachexia. WAT lipolysis was increased in early- and late-stage cachexia, while WAT browning was detected only in late-stage cachexia. Anti-IL-6 receptor antibody inhibited WAT lipolysis and browning in cachectic mice. CONCLUSIONS: Based on these findings, we conclude that chronic inflammation (especially that mediated by IL-6) might promote cancer cachexia by regulating WAT lipolysis in early-stage cachexia and browning in late-stage cachexia.

PHD3 Stabilizes the Tight Junction Protein Occludin and Protects Intestinal Epithelial Barrier Function.

Prolyl hydroxylase domain proteins (PHDs) control cellular adaptation to hypoxia. PHDs are found involved in inflammatory bowel disease (IBD); however, the exact role of PHD3, a member of the PHD family, in IBD remains unknown. We show here that PHD3 plays a critical role in maintaining intestinal epithelial barrier function. We found that genetic ablation of Phd3 in intestinal epithelial cells led to spontaneous colitis in mice. Deletion of PHD3 decreases the level of tight junction protein occludin, leading to a failure of intestinal epithelial barrier function. Further studies indicate that PHD3 stabilizes occludin by preventing the interaction between the E3 ligase Itch and occludin, in a hydroxylase-independent manner. Examination of biopsy of human ulcerative colitis patients indicates that PHD3 is decreased with disease severity, indicating that PHD3 down-regulation is associated with progression of this disease. We show that PHD3 protects intestinal epithelial barrier function and reveal a hydroxylase-independent function of PHD3 in stabilizing occludin. These findings may help open avenues for developing a therapeutic strategy for IBD.

The Endoplasmic Reticulum Stress Sensor IRE1α in Intestinal Epithelial Cells Is Essential for Protecting against Colitis.

Intestinal epithelial cells (IECs) have critical roles in maintaining homeostasis of intestinal epithelium. Endoplasmic reticulum (ER) stress is implicated in intestinal epithelium homeostasis and inflammatory bowel disease; however, it remains elusive whether IRE1α, a major sensor of ER stress, is directly involved in these processes. We demonstrate here that genetic ablation of Ire1α in IECs leads to spontaneous colitis in mice. Deletion of IRE1α in IECs results in loss of goblet cells and failure of intestinal epithelial barrier function. IRE1α deficiency induces cell apoptosis through induction of CHOP, the pro-apoptotic protein, and sensitizes cells to lipopolysaccharide, an endotoxin from bacteria. IRE1α deficiency confers upon mice higher susceptibility to chemical-induced colitis. These results suggest that IRE1α functions to maintain the intestinal epithelial homeostasis and plays an important role in defending against inflammation bowel diseases.