Down-regulation of PLCγ2-β-catenin pathway promotes activation and expansion of myeloid-derived suppressor cells in cancer

Myeloid-derived suppressor cells (MDSCs) favor tumor promotion, mainly by suppressing antitumor T cell responses in many cancers. Although the mechanism of T cell inhibition is established, the pathways leading to MDSC accumulation in bone marrow and secondary lymphoid organs of tumor-bearing hosts remain unclear. We demonstrate that down-regulation of PLCγ2 signaling in MDSCs is responsible for their aberrant expansion during tumor progression. PLCγ2(−/−) MDSCs show stronger immune-suppressive activity against CD8(+) T cells than WT MDSCs and potently promote tumor growth when adoptively transferred into WT mice. Mechanistically, PLCγ2(−/−) MDSCs display reduced β-catenin levels, and restoration of β-catenin expression decreases their expansion and tumor growth. Consistent with a negative role for β-catenin in MDSCs, its deletion in the myeloid population leads to MDSC accumulation and supports tumor progression, whereas expression of β-catenin constitutively active reduces MDSC numbers and protects from tumor growth. Further emphasizing the clinical relevance of these findings, MDSCs isolated from pancreatic cancer patients show reduced p-PLCγ2 and β-catenin levels compared with healthy controls, similar to tumor-bearing mice. Thus, for the first time, we demonstrate that down-regulation of PLCγ2–β-catenin pathway occurs in mice and humans and leads to MDSC-mediated tumor expansion, raising concerns about the efficacy of systemic β-catenin blockade as anti-cancer therapy

Jaundice: an important, poorly recognized risk factor for diminished survival in patients with adenocarcinoma of the head of the pancreas

AbstractObjectivesJaundice impairs cellular immunity, an important defence against the dissemination of cancer. Jaundice is a common mode of presentation in pancreatic head adenocarcinoma. The purpose of this study was to determine whether there is an association between preoperative jaundice and survival in patients who have undergone resection of such tumours.MethodsThirty possible survival risk factors were evaluated in a database of over 400 resected patients. Univariate analysis was used to determine odds ratio for death. All factors for which a P‐value of <0.30 was obtained were entered into a multivariate analysis using the Cox model with backward selection.ResultsPreoperative jaundice, age, positive node status, poor differentiation and lymphatic invasion were significant indicators of poor outcome in multivariate analysis. Absence of jaundice was a highly favourable prognostic factor. Interaction emerged between jaundice and nodal status. The benefit conferred by the absence of jaundice was restricted to patients in whom negative node status was present. Five‐year overall survival in this group was 66%. Jaundiced patients who underwent preoperative stenting had a survival advantage.ConclusionsPreoperative jaundice is a negative risk factor in adenocarcinoma of the pancreas. Additional studies are required to determine the exact mechanism for this effect

Predicting outcomes in patients undergoing pancreatectomy using wearable technology and machine learning: Prospective cohort study

BACKGROUND: Pancreatic cancer is the third leading cause of cancer-related deaths, and although pancreatectomy is currently the only curative treatment, it is associated with significant morbidity. OBJECTIVE: The objective of this study was to evaluate the utility of wearable telemonitoring technologies to predict treatment outcomes using patient activity metrics and machine learning. METHODS: In this prospective, single-center, single-cohort study, patients scheduled for pancreatectomy were provided with a wearable telemonitoring device to be worn prior to surgery. Patient clinical data were collected and all patients were evaluated using the American College of Surgeons National Surgical Quality Improvement Program surgical risk calculator (ACS-NSQIP SRC). Machine learning models were developed to predict whether patients would have a textbook outcome and compared with the ACS-NSQIP SRC using area under the receiver operating characteristic (AUROC) curves. RESULTS: Between February 2019 and February 2020, 48 patients completed the study. Patient activity metrics were collected over an average of 27.8 days before surgery. Patients took an average of 4162.1 (SD 4052.6) steps per day and had an average heart rate of 75.6 (SD 14.8) beats per minute. Twenty-eight (58%) patients had a textbook outcome after pancreatectomy. The group of 20 (42%) patients who did not have a textbook outcome included 14 patients with severe complications and 11 patients requiring readmission. The ACS-NSQIP SRC had an AUROC curve of 0.6333 to predict failure to achieve a textbook outcome, while our model combining patient clinical characteristics and patient activity data achieved the highest performance with an AUROC curve of 0.7875. CONCLUSIONS: Machine learning models outperformed ACS-NSQIP SRC estimates in predicting textbook outcomes after pancreatectomy. The highest performance was observed when machine learning models incorporated patient clinical characteristics and activity metrics

Tumor-induced STAT3 activation in monocytic myeloid-derived suppressor cells enhances stemness and mesenchymal properties in human pancreatic cancer

Pancreatic cancer (PC) mobilizes myeloid cells from the bone marrow to the tumor where they promote tumor growth and proliferation. Cancer stem cells (CSCs) are a population of tumor cells that are responsible for tumor initiation. Aldehyde dehydrogenase-1 activity in PC identifies CSCs, and its activity has been correlated with poor overall prognosis in human PC. Myeloid cells have been shown to impact tumor stemness, but the impact of immunosuppressive tumor-infiltrating granulocytic and monocytic myeloid-derived suppressor cells (Mo-MDSC) on ALDH1(Bright) CSCs and epithelial to mesenchymal transition is not well understood. In this study, we demonstrate that Mo-MDSC (CD11b(+)/Gr1(+)/Ly6G(−)/Ly6C(hi)) significantly increase the frequency of ALDH1(Bright) CSCs in a mouse model of PC. Additionally, there was significant upregulation of genes associated with epithelial to mesenchymal transition. We also found that human PC converts CD14(+) peripheral blood monocytes into Mo-MDSC (CD14(+)/HLA-DR(low/−)) in vitro, and this transformation is dependent on the activation of the STAT3 pathway. In turn, these Mo-MDSC increase the frequency of ALDH1(Bright) CSCs and promote mesenchymal features of tumor cells. Finally, blockade of STAT3 activation reversed the increase in ALDH1(Bright) CSCs. These data suggest that the PC tumor microenvironment transforms monocytes to Mo-MDSC by STAT3 activation, and these cells increase the frequency of ALDH1(Bright) CSCs. Therefore, targeting STAT3 activation may be an effective therapeutic strategy in targeting CSCs in PC. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00262-014-1527-x) contains supplementary material, which is available to authorized users

Technique and audited outcomes of laparoscopic distal pancreatectomy combining the clockwise approach, progressive stepwise compression technique, and staple line reinforcement

Background: Laparoscopic distal pancreatectomy (LDP) has proven advantages over its open counterpart and is becoming more frequently performed around the world. It still remains a difficult operation due to the retroperitoneal location of the pancreas and limited experience and training with the procedure. In addition, complications such as bleeding or postoperative pancreatic fistula (POPF) remain a problem. A standardized approach to LDP with stepwise graded compression technique for pancreatic transection has been utilized at a single center, and we sought to describe the technique and determine the outcomes. Methods: A review of all patients undergoing LDP by a clockwise approach including the graded compression technique from August 1, 2008 to December 31, 2017 was performed. An external audit was performed by the Dutch Pancreatic Cancer Group. Results: Overall, 260 patients with a mean age and a BMI of 62.3 and 28, respectively, underwent LDP using this technique. Mean operative time and blood loss were 183 min and 248 mL, respectively,. Hand-assisted method and conversion to open were both 5%. Major morbidity and mortality were 9.2% and 0.4%, respectively,. POPF was noted in 8.1%. The technical steps include (1) mobilization of the splenic flexure of the colon and exposure of the pancreas, (2) dissection along the inferior edge of the pancreas and choosing the site for pancreatic division, (3) pancreatic parenchymal division using a progressive stepwise compression technique with staple line reinforcement, (4) ligation of the splenic vein and artery, (5) dissection along the superior edge of the pancreas and residual posterior attachments, and (6) mobilization of the spleen and specimen removal. Conclusion: LDP with a clockwise approach for dissection, combined with the progressive stepwise compression technique for pancreatic transection, resulted in excellent outcomes including a very low POPF rate