Dynamic Assessment of Drain Fluid Amylase Estimates the Risk of CR-POPF Following Pancreatoduodenectomy.

OBJECTIVE: To evaluate whether drain fluid amylase levels on day-1 (DFA1) and day-3 (DFA3) can reliably estimate the risk of clinically relevant-postoperative pancreatic fistula (CR-POPF) following pancreatoduodenectomy (PD) compared to either value alone or in combination with clinicopathologic variables. BACKGROUND: CR-POPF is a major source of morbidity and mortality following PD. Current drain management algorithms are variable and are mostly dependent on DFA1, while the DFA3 is seldom utilized to guide clinical decision making. METHODS: Between 2015-2020, patients who underwent PD at two high-volume pancreas centers and had intraoperative drain placement with measurement of DFA1 and DFA3 were retrospectively reviewed. Models to predict CR-POPF were constructed using DFA1, DFA3, fistula risk score (FRS) and other patient or treatment-related parameters. The fittest and more parsimonious model was used to construct a CR-POPF risk calculator. RESULTS: Nine-hundred-twenty-three patients were included in the analysis. The FRS was high in 100(10.9%), intermediate in 524(57.3%), low in 211(23.1%) and negligible in 79(8.6%) patients. The overall rate of CR-POPF was 9.2%. Five logistic regression models were constructed using variables known to be implicated in CR-POPF. A model based solely on DFA1 and DFA3 with a cross-validated area under the curve of 0.846 was selected. A calculator using DFA1 and DFA3 was created based on this model to estimate the risk of CR-POPF. CONCLUSIONS: Risk of CR-POPF following pancreatoduodenectomy can be accurately estimated based on measurement of DFA1 and DFA3. Our CR-POPF kinetics calculator can facilitate postoperative risk stratification and guide drain management algorithms.

Early detection of pancreatic cancer.

Pancreatic adenocarcinoma is a low-incident but highly mortal disease. It accounts for only 3% of estimated new cancer cases each year but is currently the fourth common cause of cancer mortality. By 2030, it is expected to be the 2(nd) leading cause of cancer death. There is a clear need to diagnose and classify pancreatic cancer at earlier stages in order to give patients the best chance at a definitive cure through surgery. Three precursor lesions that distinctly lead to pancreatic adenocarcinoma have been identified, and we have increasing understanding the non-genetic and genetic risk factors for the disease. With increased understanding about the risk factors, the familial patters, and associated accumulation of genetic mutations involved in pancreatic cancer, we know that there are mutations that occur early in the development of pancreatic cancer and that improved genetic risk-based strategies in screening for pancreatic cancer may be possible and successful at saving or prolonging lives. The remaining challenge is that current standards for diagnosing pancreatic cancer remain too invasive and too costly for widespread screening for pancreatic cancer. Furthermore, the promises of noninvasive methods of detection such as blood, saliva, and stool remain underdeveloped or lack robust testing. However, significant progress has been made, and we are drawing closer to a strategy for the screening and early detection of pancreatic cancer.

Osteopontin regulates epithelial mesenchymal transition-associated growth of hepatocellular cancer in a mouse xenograft model.

OBJECTIVE: To determine the efficacy of osteopontin (OPN) targeting in hepatocellular cancer (HCC). SUMMARY/BACKGROUND: OPN is associated with HCC growth and metastasis and represents a unique therapeutic target. METHODS: OPN and epithelial-mesenchymal transition (EMT) markers, α-smooth muscle actin (SMA), vimentin, and tenascin-c, were measured in archived human HCC tissues from metastatic (n = 4) and nonmetastatic (n = 4) settings. Additional studies utilized human Sk-Hep-1 (high OPN expression) and Hep3b (low OPN expression) HCC cells. An RNA aptamer (APT) that avidly binds (Kd = 18 nM; t1/2 = 7 hours) and ablates OPN binding was developed. Adhesion, migration/invasion, and EMT markers were determined with APT or a mutant control aptamer (Mu-APT). RFP-Luc-Sk-Hep-1 were implanted into NOD-scid mice livers and followed by using bioluminescence imaging. After verification of tumor growth, at week 3, APT (0.5 mg/kg; n = 4) or Mu-APT (0.5 mg/kg; n = 4) was injected q48h. When mice were killed at week 8, tumor cells were reisolated and assayed for EMT markers. RESULTS: OPN and EMT markers were significantly increased in the metastatic cohort. APT inhibited Sk-Hep-1 adhesion and migration/invasion by 5- and 4-fold, respectively. APT significantly decreased EMT protein markers, SMA, vimentin, and tenascin-c. In contrast, APT did not alter Hep3B adhesion, or migration/invasion. EMT markers were slightly decreased. In the in vivo model, at weeks 6 to 8, APT inhibited HCC growth by more than 10-fold. SMA, vimentin, and tenascin-c mRNAs were decreased by 60%, 40%, and 49%, respectively, in RFP-positive Sk-Hep-1 recovered by fluorescence-activated cell sorting (P < 0.04 vs Mu-APT for all). CONCLUSIONS: APT targeting of OPN significantly decreases EMT and tumor growth of HCC.

Osteopontin promotes CCL5-mesenchymal stromal cell-mediated breast cancer metastasis.

The interaction between cancer and its local microenvironment can determine properties of growth and metastasis. A critical component of the tumor microenvironment in this context is the cancer-associated fibroblast (CAF), which can promote tumor growth, angiogenesis and metastasis. It has been hypothesized that CAF may be derived from mesenchymal stromal cells (MSC), derived from local or distant sources. However, the signaling mechanisms by which tumors and MSCs interact to promote CAF-dependent cancer growth are largely unknown. In this study with in vitro and in vivo models using MDA-MB231 human breast cancer cells, we demonstrate that tumor-derived osteopontin (OPN) induces MSC production of CCL5; the mechanism involves OPN binding to integrin cell surface receptors and activator protein-1 c-jun homodimer transactivation. In a murine xenograft model, concomitant inoculation of MSC with MDA-MB231 cells induces: (i) significantly increased growth and metastasis of MB231 cells and (ii) increased MSC migration to metastatic sites in lung and liver; this mechanism is both OPN and CCL5 dependent. MSCs retrieved from sites of metastases exhibit OPN-dependent expression of the CAF markers, α-smooth muscle actin, tenascin-c, CXCL12 (or stromal cell-derived factor 1) and fibroblast-specific protein-1 and the matrix metalloproteinases (MMP)-2 and MMP-9. Based upon these results, we propose that tumor-derived OPN promotes tumor progression via the transformation of MSC into CAF.

Neoantigen-based EpiGVAX vaccine initiates antitumor immunity in colorectal cancer.

Metastatic colorectal cancer (CRC) is poorly immunogenic, with limited neoantigens that can be targeted by cancer vaccine. Previous approaches to upregulate neoantigen have had limited success. In this study, we investigated the role of a DNA methyltransferase inhibitor (DNMTi), 5-aza-2'-deoxycytidine (DAC), in inducing cancer testis antigen (CTA) expression and evaluated the antitumor efficacy of a combinatorial approach with an epigenetically regulated cancer vaccine EpiGVAX and DAC. A murine model of metastatic CRC treated with combination therapy with an irradiated whole-cell CRC vaccine (GVAX) and DAC was used to assess the antitumor efficacy. DAC significantly induced expression of CTAs in CRC, including a new CTA Tra-P1A with a known neoepitope, P1A. Epigenetically modified EpiGVAX with DAC improved survival outcomes of GVAX. Using the epigenetically regulated antigen Tra-P1A as an example, our study suggests that the improved efficacy of EpiGVAX with DAC may due in part to the enhanced antigen-specific antitumor immune responses. This study shows that epigenetic therapy with DNMTi can not only induce new CTA expression but may also sensitize tumor cells for immunotherapy. Neoantigen-based EpiGVAX combined with DAC can improve the antitumor efficacy of GVAX by inducing antigen-specific antitumor T cell responses to epigenetically regulated proteins.

Dissecting the Stromal Signaling and Regulation of Myeloid Cells and Memory Effector T Cells in Pancreatic Cancer.

PURPOSE: Myeloid cells are a prominent immunosuppressive component within the stroma of pancreatic ductal adenocarcinoma (PDAC). Previously, targeting myeloid cells has had limited success. Here, we sought to target the myeloid cells through modifying a specific stromal component. EXPERIMENTAL DESIGN: A murine model of metastatic PDAC treated with an irradiated whole-cell PDAC vaccine and PDAC specimens from patients treated with the same type of vaccine were used to assess the immune-modulating effect of stromal hyaluronan (HA) degradation by PEGPH20. RESULTS: Targeting stroma by degrading HA with PEGPH20 in combination with vaccine decreases CXCL12/CXCR4/CCR7 immunosuppressive signaling axis expression in cancer-associated fibroblasts, myeloid, and CD8+ T cells, respectively. This corresponds with increased CCR7- effector memory T-cell infiltration, an increase in tumor-specific IFNγ, and improved survival. In the stroma of human PDACs treated with the same vaccine, decreased stromal CXCR4 expression significantly correlated with decreased HA and increased cytotoxic activities, suggesting CXCR4 is an important therapeutic target. CONCLUSIONS: This study represents the first to dissect signaling cascades following PDAC stroma remodeling via HA depletion, suggesting this not only overcomes a physical barrier for immune cell trafficking, but alters myeloid function leading to downstream selective increases in effector memory T-cell infiltration and antitumor activity.

Anti-pancreatic tumor efficacy of a Listeria-based, Annexin A2-targeting immunotherapy in combination with anti-PD-1 antibodies.

BACKGROUND: Immune checkpoint inhibitors are not effective for pancreatic ductal adenocarcinoma (PDAC) as single agents. Vaccine therapy may sensitize PDACs to checkpoint inhibitor treatments. Annexin A2 (ANXA2) is a pro-metastasis protein, previously identified as a relevant PDAC antigen that is expressed by a GM-CSF-secreting allogenic whole pancreatic tumor cell vaccine (GVAX) to induce an anti-ANXA2 antibody response in patients with PDAC. We hypothesized that an ANXA2-targeting vaccine approach not only provokes an immune response but also mounts anti-tumor effects. METHODS: We developed a Listeria-based, ANXA2-targeting cancer immunotherapy (Lm-ANXA2) and investigated its effectiveness within two murine models of PDAC. RESULTS: We show that Lm-ANXA2 prolonged the survival in a transplant model of mouse PDACs. More importantly, priming with the Lm-ANXA2 treatment prior to administration of anti-PD-1 antibodies increased cure rates in the implanted PDAC model and resulted in objective tumor responses and prolonged survival in the genetically engineered spontaneous PDAC model. In tumors treated with Lm-ANXA2 followed by anti-PD-1 antibody, the T cells specific to ANXA2 had significantly increased INFγ expression. CONCLUSIONS: For the first time, a listeria vaccine-based immunotherapy was shown to be able to induce a tumor antigen-specific T cell response within the tumor microenvironment of a "cold" tumor such as PDAC and sensitize the tumor to checkpoint inhibitor therapy. Moreover, this combination immunotherapy led to objective tumor responses and survival benefit in the mice with spontaneously developed PDAC tumors. Therefore, our study supports developing Lm-ANXA2 as a therapeutic agent in combination with anti-PD-1 antibody for PDAC treatment.

Case Report: Collision Tumour of Colon Leiomyosarcoma and Adenocarcinoma.

The colon is an exceedingly rare site of primary leiomyosarcoma and only a few cases have been published to date. Of the reported cases of collision tumours, collision tumours that specifically occurred in the colon have consisted of combinations of adenoma or adenocarcinoma with lymphomas or neuroendocrine tumours. Here, not only do we report a case of colon leiomyosarcoma, but we report, what is to our knowledge, the first case of collision tumour consisting of colon leiomyosarcoma and adenocarcinoma. Cause, prognosis, and treatment of colon collision tumours vary and are yet to be understood.

Micro-RNA-181a regulates osteopontin-dependent metastatic function in hepatocellular cancer cell lines.

BACKGROUND: Osteopontin (OPN) is a variably expressed, secreted glycophosphoprotein that mediates the growth and metastases of hepatocellular cancer (HCC). MicroRNAs (miRNAs) may be responsible for variant OPN expression, interrupting translation by binding OPN messenger RNA (mRNA) in 3'-untranslated regions (UTRs). METHODS: A microarray analysis identified miRNAs of interest. Plasmid constructs using a luciferase reporter with variable OPN 3'UTR mutations were transfected into 2 HCC cell lines to determine miRNA regulation of OPN expression. Western blot analyses confirmed variable OPN expression in both cell lines. Invasion, adhesion, and migration evaluated metastatic behavior in Hep G2 and Hep 3B with modified miRNA and OPN expression. RESULTS: Hep 3B produces 36 x miRNA 181a compared with Hep G2. Luciferase activity after transfection with miRNA 181a precursor was decreased in both cell lines (P < .01); luciferase activity increased with miRNA 181a inhibitor transfection in both cell lines (P < .01). Hep 3B transfected with mutated OPN 3'UTR increased luciferase activity 108% (P < .01). Hep G2 transfected with miRNA precursor decreased OPN expression 5 x (P < .01) in Western blot analyses. Hep 3B transfection with miRNA precursor increased OPN expression 3 x (P < .01) in Western blot analyses. In vitro metastatic correlates increased in Hep 3B lines after transfection with siOPN and/or miRNA 181a inhibitor (P < .01). CONCLUSION: MiRNA 181a decreases OPN expression in HCC cell lines. This previously undescribed mechanism may confer metastatic characteristics to HCC.