Complications and outcome after laparoscopic bariatric surgery: LAGB versus LRYGB.

BACKGROUND AND AIMS: Unsatisfactory patient compliance and unfavorable results of weight loss let centers prefer the Roux-en-Y gastric bypass (RYGB) as a combined restrictive and malabsorptive procedure. The aim of this study was to evaluate results of laparoscopic adjustable gastric banding (LAGB) versus laparoscopic RYGB. SETTING: The study was conducted at Centre Hospitalier Emil Mayrisch Clinic for specialized care (n = 618 beds) in Luxembourg (South). MATERIALS AND METHODS: Of 620 procedures, 204 patients had LAGB and 416 LRYGB. Short-term (t(1), 6 months to 2 years), middle-term (t(2), 2 to 5 years), and long-term follow-up (t(3), >5 years) were performed, including weight loss evolution, Bariatric Analysis, and Reporting Outcome System (BAROS). RESULTS: Percent EBWL mean values for LAGB vs. LRYGB were at t(1) 64.3 vs. 79.5, p = 0.01; at t(2) 49.4 vs. 91, p < 0.0001; and at t(3) 52.6 vs. 79.9, p < 0.0001. The BAROS mean values were at t(1) 3.81 vs. 4.00, p = 0.183; at t(2) 3.57 vs. 4.12, p < 0.001; and at t(3) 3.71 vs. 4.04, p = 0.02. Major complication rate (<30 days) was similar (p = 0.601). Long-term (>30 days) complications were more common after LAGB (14.3 versus 3.6%, p < 0.001). Fifty patients (25%) required a second and 36 patients (18%) a third operation (LRYGB). CONCLUSION: The significant difference in %EBWL and BAROS and late adverse events with high re-operation rates in LAGB made the LRYGB more attractive.

The gut microbial metabolite formate exacerbates colorectal cancer progression.

The gut microbiome is a key player in the immunomodulatory and protumorigenic microenvironment during colorectal cancer (CRC), as different gut-derived bacteria can induce tumour growth. However, the crosstalk between the gut microbiome and the host in relation to tumour cell metabolism remains largely unexplored. Here we show that formate, a metabolite produced by the CRC-associated bacterium Fusobacterium nucleatum, promotes CRC development. We describe molecular signatures linking CRC phenotypes with Fusobacterium abundance. Cocultures of F. nucleatum with patient-derived CRC cells display protumorigenic effects, along with a metabolic shift towards increased formate secretion and cancer glutamine metabolism. We further show that microbiome-derived formate drives CRC tumour invasion by triggering AhR signalling, while increasing cancer stemness. Finally, F. nucleatum or formate treatment in mice leads to increased tumour incidence or size, and Th17 cell expansion, which can favour proinflammatory profiles. Moving beyond observational studies, we identify formate as a gut-derived oncometabolite that is relevant for CRC progression.

A Biologic Surgical Implant in Complex Abdominal Wall Repair: 3-Year Follow-Up Results of a Multicentric Prospective Study.

PURPOSE: Despite the advancements in the reinforcement and closure techniques available, complex abdominal wall reconstruction (CAWR) remains a challenging surgical undertaking with considerable risk of postoperative complications. Biological meshes were developed that may help to complement standard closure techniques and offer an alternative to synthetic meshes, which carry significant risks with their use in complex cases. PATIENTS AND METHODS: A total of 114 patients underwent surgical treatment for CAWR with a Permacol™ (a biologic surgical implant). The study objective was to evaluate the short-term (6 months), mid-term (12-24 months), and long-term (36 months) clinical outcomes (through 36 months) associated with the use of a biologic surgical implant in these cases. RESULTS: The cumulative hernia recurrence rate was 18.7% (17/91) at 24 months and 22.4% (19/85) at 36 months. Twelve (14.1%) subjects required reoperation for hernia repair within 36 months for repair of recurrent hernias. Between 6- and 36-months post-surgery, patients reported improvement in their Carolina comfort scale (CSS) measures of severity of pain, sensation of mesh, and movement limitations. CONCLUSION: A biologic surgical implant can provide long-term benefit to complex abdominal wall repairs in patients staged grade III according to the Ventral Hernia Working Group (VHWG).

Hypoxia-induced autophagy drives colorectal cancer initiation and progression by activating the PRKC/PKC-EZR (ezrin) pathway.

In solid tumors, cancer stem cells (CSCs) or tumor-initiating cells (TICs) are often found in hypoxic niches. Nevertheless, the influence of hypoxia on TICs is poorly understood. Using previously established, TIC-enrichedpatient-derived colorectal cancer (CRC) cultures, we show that hypoxia increases the self-renewal capacity of TICs while inducing proliferation arrest in their more differentiated counterpart cultures. Gene expression data revealed macroautophagy/autophagy as one of the major pathways induced by hypoxia in TICs. Interestingly, hypoxia-induced autophagy was found to induce phosphorylation of EZR (ezrin) at Thr567 residue, which could be reversed by knocking down ATG5, BNIP3, BNIP3L, or BECN1. Furthermore, we identified PRKCA/PKCα as a potential kinase involved in hypoxia-induced autophagy-mediated TIC self-renewal. Genetic targeting of autophagy or pharmacological inhibition of PRKC/PKC and EZR resulted in decreased tumor-initiating potential of TICs. In addition, we observed significantly reduced in vivo tumor initiation and growth after a stable knockdown of ATG5. Analysis of human CRC samples showed that p-EZR is often present in TICs located in the hypoxic and autophagic regions of the tumor. Altogether, our results establish the hypoxia-autophagy-PKC-EZR signaling axis as a novel regulatory mechanism of TIC self-renewal and CRC progression. Autophagy inhibition might thus represent a promising therapeutic strategy for cancer patients. ABBREVIATIONS: ATG: autophagy related; BECN1: beclin 1; BNIP3: BCL2 interacting protein 3; BNIP3L: BCL2 interacting protein 3 like; CQ: chloroquine; CSC: cancer stem cells; CRC: colorectal cancer; HIF1A/HIF-1α: hypoxia inducible factor 1 subunit alpha; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; PRKC/PKC: protein kinase C; SQSTM1/p62: sequestosome 1; TICs: tumor-initiating cells.

Tumor suppressor miR-215 counteracts hypoxia-induced colon cancer stem cell activity.

Cancer stem cells, also known as tumor-initiating cells (TICs), are a population of aggressive and self-renewing cells that are responsible for the initiation and progression of many cancers, including colorectal carcinoma. Intratumoral hypoxia, i.e. reduced oxygen supply following uncontrolled proliferation of cancer cells, is thought to support TIC activity by inducing specific hypoxia-responsive mechanisms that are not yet entirely understood. Using previously established and fully characterized patient-derived TIC cultures, we could observe increased sphere and colony formation under hypoxic conditions. Mechanistically, microRNA (miRNA)-profiling experiments allowed us to identify miR-215 as one of the main hypoxia-induced miRNAs in primary colon TICs. Through stable overexpression of miR-215, followed by a set of functional in vitro and in vivo investigations, miR-215 was pinpointed as a negative feedback regulator, working against the TIC-promoting effects of hypoxia. Furthermore, we could single out LGR5, a bona fide marker of non-neoplastic intestinal stem cells, as a downstream target of hypoxia/miR-215 signaling. The strong tumor- and TIC-suppressor potential of miR-215 and the regulatory role of the hypoxia/miR-215/LGR5 axis may thus represent interesting points of attack for the development of innovative anti-CSC therapy approaches.