Wang, Huamin

e16479 Background: Recent genomic data has demonstrated SBA to be a molecularly unique entity when compared to colon or gastric cancers. The ongoing SWOG 1922 randomized clinical trial is comparing FOLFIRI to ramucirumab/paclitaxel as the second-line treatment for metastatic SBA. We sought to further define the activity of taxane-based therapy in the largest collection of SBA patients treated with this therapy. Methods: A retrospective review of SBA patients treated with taxane-based chemotherapy from 1994 to 2024 at MD Anderson Cancer Center was performed. All patients had pathologic confirmation, received > 1 cycle of therapy, and had documented tumor response evaluation. Response was assessed by the treating physician based on the imaging studies and categorized as response, stable disease or progression. Patient demographics, clinical parameters, molecular data, and taxane treatment was reviewed. Kaplan-Meier survival analysis was performed to calculate time to progression (TTP) and overall survival (OS). Results: 70 SBA patients treated with taxane-based therapy were identified. The median age at diagnosis was 57 years (range 33-80 years), majority being male (59%) with primary tumor located at duodenum (44%), Jejunum (34%), Ileum (16%). The most common presenting metastatic site was peritoneum (39%), followed by liver (31%). The genomic status revealed mutations in the following genes: 62% TP53, 47% KRAS, 24% SMAD4, and 15% APC. Taxane treatment was single agent (nab-paclitaxel, paclitaxel, or docetaxel) in 29%, gemcitabine and taxane combination in 61% and other taxane-based combinations in 10%. Therapy was given in the metastatic setting as 2nd-line in 40%, 3rd-line in 33% and 4th-line or greater in 20%. Response status was response in 24%, stable disease in 26%, and progression in 50%. Median TTP was 3.1 months (95%CI: 2.0-4.2 months), and median OS was 8.7 months (95%CI: 7.4-10.1 months). Median TTP was similar between single agent (2.6 months) and gemcitabine-based combination (2.5 months) (p =0.75). Efficacy did not differ by line of therapy nor primary tumor site. Efficacy differed by TP53 mutation status: TP53 mutated vs wildtype (response 21% vs 43%, p = 0.02; median TTP 2.4m vs 4.9m, p = 0.013; median OS 7.3m vs 10.6m, p = 0.004). Conclusions: This retrospective study of 70 SBA patients confirms the activity of taxane-based therapy demonstrating a response rate of 24% and median TTP of 3.1 months. Though limited by sample size, TP53 mutations may represent a negative predictive marker for taxane-based therapy in SBA patients. These findings support the ongoing SWOG 1922 trial investigating taxane-based therapy as a second line for metastatic SBA.

Abstract Background: Pancreatitis is an inflammatory disease of the pancreas that causes significant morbidity and mortality and is one of the major risk factors for pancreatic cancer. Protein phosphatase 4 (PP4) has been reported to be overexpressed in breast, lung and pancreatic cancers. PP4 plays an important role in the regulation of centrosome maturation, DNA repair, NF-κB, and c-jun-NH2-kinase (JNK) signaling pathways. However, the expression and functions of PP4 in pancreatitis have not been studied. Methods: To examine the functions of PP4 in cerulein-induced acute pancreatitis (AP), we crossed PP4flox/+ mice with pancreatic acinar cell specific cre, CreERT, which was driven by a full length pancreatic acinar specific elastase I promoter. PP4flox/flox, CreERT mice and control mice were treated with 8 hourly intraperitoneal injections of cerulein (50 µg/kg/h). The pancreata were harvested at different time points for histopathological examination and molecular analysis. Results: PP4 expression was increased at both protein and mRNA levels in mouse pancreas with AP. Compared to CreERT mice, PP4flox/flox, CreERT mice demonstrated significantly less edema, less inflammation, less necrosis or loss of pancreatic acinar cells in pancreas after cerulein treatment. The serum amylase and lipase levels were lower in cerulein-treated PP4flox/flox, CreERT mice compared with controls. The pancreata of PP4flox/flox, CreERT mice exhibited decreased STAT3 Tyr705 phosphorylation and decreased NF-κB activation cerulein-treated PP4flox/flox, CreERT mice than control mice. Conclusion: Our findings demonstrated that PP4 plays an important role in cerulein-induced AP through STAT3 and NF-κB signaling pathways. Inhibition of PP4 may help to reduce the pancreatic injuries and to prevent the development of chronic pancreatitis, which increases the risk of pancreatic cancer. Citation Format: Hua Wang, Reza Abbasgholizadeh, Rohan Moniruzzaman, Baoan Ji, Anirban Maitra, Huamin Wang. Protein phosphatase 4 deficiency protects mice against cerulein-induced acute pancreatitis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB568.

Currently, there are no internationally accepted consensus guidelines for pathologic evaluation of posttherapy pancreatectomy specimens. The Neoadjuvant Therapy Working Group of Pancreatobiliary Pathology Society was formed in 2018 to review grossing protocols, literature, and major issues and to develop recommendations for pathologic evaluation of posttherapy pancreatectomy specimens. The working group generated the following recommendations: (1) Systematic and standardized grossing and sampling protocols should be adopted for pancreatectomy specimens for treated pancreatic ductal adenocarcinoma (PDAC). (2) Consecutive mapping sections along the largest gross tumor dimension are recommended to validate tumor size by histology as required by the College of American Pathologists (CAP) cancer protocol. (3) Tumor size of treated PDACs should be measured microscopically as the largest dimension of tumor outer limits that is bound by viable tumor cells, including intervening stroma. (4) The MD Anderson grading system for tumor response has a better correlation with prognosis and better interobserver concordance among pathologists than does the CAP system. (5) A case should not be classified as a complete response unless the entire pancreas, peripancreatic tissues, ampulla of Vater, common bile duct, and duodenum adjacent to the pancreas are submitted for microscopic examination. (6) Future studies on tumor response of lymph node metastases, molecular and/or immunohistochemical markers, as well as application of artificial intelligence in grading tumor response of treated PDAC are needed. In summary, systematic, standardized pathologic evaluation, accurate tumor size measurement, and reproducible tumor response grading to neoadjuvant therapy are needed for optimal patient care. The criteria and discussions provided here may provide guidance towards these goals.

Abstract Context. —Primary esophageal melanoma (PEM) is a rare disease and is difficult to distinguish from other esophageal malignancies and from metastatic melanoma. Objective. —To develop diagnostic criteria for PEM, we compared the clinicopathologic features of 5 PEMs and 5 metastatic melanomas to esophagus. Design. —Ten cases of esophageal melanoma, including 4 surgically resected specimens, 2 autopsy cases, and 4 cases reported on mucosal biopsies, were reviewed. The histologic parameters used in this study were well-characterized features for cutaneous melanoma, including junctional component (in situ melanoma), radial growth phase, modified Breslow thickness, depth of invasion, lymphovascular invasion, satellitosis, predominant type of cytology, and regional lymph node metastasis. Clinical and follow-up information was obtained by reviewing patients' medical records. Results. —Previous history of cutaneous melanoma was present in all 5 cases of metastatic esophageal melanoma but was not present in the 5 patients with PEMs. In situ melanoma and/or radial growth phase were identified in all 5 PEMs but were not present in any of the metastatic cases. Among the 4 resected and 2 autopsy cases, melanocytosis and mixed epithelioid and spindle cell morphology was present in 2 (50%) of 4 PEMs but was not present in 2 (40%) of the metastatic melanomas. Melanin pigment was detectable in all cases. Patients with PEM had better survival than those who had metastatic melanoma to esophagus ( P = .03). Conclusions. —The presence of in situ melanoma, radial growth phase, melanocytosis, and mixed epithelioid and spindle cell morphology, in the context of no history of melanoma, distinguishes PEM from metastatic melanoma.

Abstract Obesity is a risk factor for Pancreatic Ductal Adenocarcinoma (PDAC), but the molecular mechanisms involved are unclear. Oncogenic mutation of K-Ras occurs early and nearly universally in patients with this disease. However, recent evidence indicates that oncogenic Ras is not fully active and for activity to surpass the threshold required to engage a Ras-inflammation feed-forward loop, it requires a stimulus. We hypothesized that high-fat intake acts as an inflammatory stimulus, increasing K-Ras activity and that cyclooxygenase -2 (COX2) expression is required in the inflammatory loop. LSL-K-Ras mice were crossed with elastase-CreER (acinar cell-specific) or Pdx1-Cre (pancreatic cell-specific) to “knock-in” expression of oncogenic K-Ras. Additionally, acinar cell-specific -Ras mice were crossed with COX2 conditional knockout mice. All mice were fed isocaloric diets with different amounts of fat and a COX2 inhibitor was administered to some acinar cell-specific -Ras mice. Pancreata were analyzed for Ras activity, Phospho-ERK levels, inflammation, fibrosis, PanIN and PDAC development. We observed that consumption of a high fat diet (HFD) led to increased K-Ras activity, PanIN formation, fibrotic stroma and PDAC development compared to a control diet. Additionally, we observed a significant reduction in the survival of mice fed a HFD. Genetic deletion of COX2 in acinar cells and COX2 systemic inhibition prevented the HFD-induced effects in acinar cell-specific -Ras mice. These findings indicated that a HFD stimulates activation of oncogenic K-Ras and initiates an inflammatory feed-forward loop requiring the expression of COX2 leading to pancreatic inflammation, fibrosis, PanINs and PDAC. This mechanism may explain the PDAC risks associated with consumption of a HFD. Citation Format: Bincy Philip, Christina L. Roland, Jarek Daniluk, Yan Liu, Deyali Chatterjee, Sobeyda Berenice Gomez, Baoan Ji, Huang Haojie, Huamin Wang, Jason B. Fleming, Craig D. Logsdon, Zobeida Cruz-Monserrate. High fat triggers oncogenic K-Ras activity and a COX2 dependent feed-forward loop to induce pancreatic ductal adenocarcinoma development. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr C61.

Replacement of the exocrine parenchyma by fibrous tissue is a main characteristic of chronic pancreatitis. Understanding the mechanisms of pancreatic fibrogenesis is critical for the development of preventive and therapeutic interventions. Cyclooxygenase-2 (COX-2), a rate-limiting enzyme for prostaglandin synthesis, is expressed in patients with chronic pancreatitis. However, it is unknown whether COX-2 can cause chronic pancreatitis. To investigate the roles of pancreatic acinar COX-2 in fibrogenesis and the development of chronic pancreatitis, COX-2 was ectopically expressed specifically in pancreatic acinar cells in transgenic mice. Histopathological changes and expression levels of several profibrogenic factors related to chronic pancreatitis were evaluated. COX-2 was expressed in the pancreas of the transgenic mice, as detected by Western blot analysis. Immunohistochemical staining showed COX-2 was specifically expressed in pancreatic acinar cells. COX-2 expression led to progressive changes in the pancreas, including pancreas megaly, persistent inflammation, collagen deposition, and acinar-to-ductal metaplasia. Quantitative RT-PCR and immunostaining showed that profibrogenic factors were upregulated and pancreatic stellate cells were activated in the COX-2 transgenic mice. Expression of COX-2 in pancreatic acinar cells is sufficient to induce chronic pancreatitis. Targeting this pathway may be valuable in the prevention of chronic pancreatitis. NEW & NOTEWORTHY COX-2 expression is observed in pancreatic tissues of human chronic pancreatitis. In this study, we showed that COX-2 expression caused the development of chronic pancreatitis in transgenic mice, supporting the idea that COX-2 inhibition may be an effective preventive and therapeutic strategy.

Abstract Introduction: We and others have shown that pancreatic stellate cells (PSCs) in the tumor-associated stroma of PDAC promote tumor progression and resistance to therapy but the precise mechanisms are unclear. We investigated the role of PSC-derived DKK3, a member of the Dickkopf family of glycoproteins, in PDAC progression, metastasis and response to chemotherapy. Methods: We evaluated expression of DKK3 in human PDAC tissue and cell lines, human PSCs and in a genetically engineered mouse model (GEMM) of PDAC. The paracrine and autocrine effects of DKK3 on PDAC and PSCs were examined by treatment with exogenous DKK3 and gain- and loss of function assays for proliferation, migration, invasion, and gemcitabine-induced apoptosis. The effects of DKK3 on PDAC progression and metastasis were determined by shRNA neutralization and genetic ablation in orthotopic xenograft models and the KPC autochthonous model of PDAC. We developed novel monoclonal antibodies (mAbs) against DKK3 and tested their ability to neutralize DKK3 and prolong survival in mouse models of PDAC. Results: DKK3 was expressed at 4.5 times higher levels in human PDAC by Affymetrix profiling compared to normal pancreas and was present in 99% (118/119) of samples on a tissue microarray with moderate to high expression in 59%. In a GEMM of PDAC, DKK3 appeared early with preneoplastic PanIN lesions with increased expression in invasive carcinoma. DKK3 was strongly expressed by PSCs with minimal to no expression in PDAC cells and knockdown by shRNA reduced PSC proliferation and migration by 60% and 84% compared to controls (p<0.001). Treatment of Panc1 and BxPC3 cells with DKK3 stimulated migration and invasion by 100-300% (p<0.001) and proliferation of DKK3-silenced Panc1 cells was decreased by 80% (p<0.001). Overexpression of DKK3 in L3.6pl cells increased colony formation in gemcitabine by >90% (p<0.001) with 65% reduction in apoptosis (p<0.01), indicating that DKK3 contributes to PDAC resistance to chemotherapy. When we ablated DKK3 in KPC mice by breeding with DKK3-knockout mice, tumor growth was inhibited and survival increased by 45% (p=0.0002). In addition, fewer PanIN lesions developed in DKK3-null mice suggesting that DKK3 may contribute to the early developmental stages of PDAC. DKK3 neutralizing mAbs abrogated DKK3-mediated induction of PDAC cell migration, invasion and resistance to gemcitabine in vitro. Furthermore, treatment with DKK3 mAb significantly inhibited primary tumor growth, reduced peritoneal metastases and prolonged survival in an orthotopic model of PDAC by 43% compared to control mAb (p=0.005; HR 0.24, 95% CI 0.01-0.30). Conclusions: These data are the first report, to our knowledge, of a tumor-promoting function of DKK3 and our results suggest that neutralization of DKK3 may be an effective approach as a primary treatment for PDAC and to enhance responsiveness to chemotherapy. Citation Format: Liran Zhou, Hongmei Husted, Todd Moore, Mason Lu, Defeng Deng, Yan Liu, Vijaya Ramachandran, Thiruvengadam Arumugam, Baoan Ji, Huamin Wang, Jeffrey E. Lee, Craig D. Logsdon, Rosa F. Hwang. Targeting stromal-derived Dickkopf-3 (DKK3) for the treatment of pancreatic ductal adenocarcinoma (PDAC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2961. doi:10.1158/1538-7445.AM2017-2961

Abstract Lipocalin-2 (LCN2) promotes malignant development in many cancer types. LCN2 is upregulated in patients with pancreatic ductal adenocarcinoma (PDAC) and in obese individuals, but whether it contributes to PDAC development is unclear. In this study, we investigated the effects of Lcn2 depletion on diet-induced obesity, inflammation, and PDAC development. Mice with acinar cell–specific expression of KrasG12D were crossed with Lcn2-depleted animals and fed isocaloric diets with varying amounts of fat content. Pancreas were collected and analyzed for inflammation, pancreatic intraepithelial neoplasia (PanIN), and PDAC. We also used a syngeneic orthotopic PDAC mouse model to study tumor growth in the presence or absence of Lcn2 expression. In addition, to understand the mechanistic role of how LCN2 could be mediating PDAC, we studied LCN2 and its specific receptor solute carrier family 22 member 17 (SLC22A17) in human pancreatic cancer stellate cells (PSC), key mediators of the PDAC stroma. Depletion of Lcn2 diminished extracellular matrix deposition, immune cell infiltration, PanIN formation, and tumor growth. Notably, it also increased survival in both obesity-driven and syngeneic orthotopic PDAC mouse models. LCN2 modulated the secretion of proinflammatory cytokines in PSC of the PDAC tumor microenvironment, whereas downregulation of LCN2-specific receptor SLC22A17 blocked these effects. Our results reveal how LCN2 acts in the tumor microenvironment links obesity, inflammation, and PDAC development. Cancer Res; 77(10); 2647–60. ©2017 AACR

Abstract Purpose: Pancreatic ductal adenocarcinoma (PDAC) is lethal cancer whose primary tumor is characterized by dense composition of cancer cells, stromal cells, and extracellular matrix (ECM) composed largely of collagen. Within the PDAC tumor microenvironment, activated pancreatic stellate cells (PSC) are the dominant stromal cell type and responsible for collagen deposition. Lumican is a secreted proteoglycan that regulates collagen fibril assembly. We have previously identified that the presence of lumican in the ECM surrounding PDAC cells is associated with improved patient outcome after multimodal therapy and surgical removal of localized PDAC. Experimental Design: Lumican expression in PDAC from 27 patients was determined by IHC and quantitatively analyzed for colocalization with PSCs. In vitro studies examined the molecular mechanisms of lumican transcription and secretion from PSCs (HPSCs and HPaSteC), and cell adhesion and migration assays examined the effect of lumican on PSCs in a collagen-rich environment. Results: Here we identify PSCs as a significant source of extracellular lumican production through quantitative IHC analysis. We demonstrate that the cytokine, TGF-β, negatively regulates lumican gene transcription within HPSCs through its canonical signaling pathway and binding of SMAD4 to novel SBEs identified within the promoter region. In addition, we found that the ability of HPSCs to produce and secrete extracellular lumican significantly enhances HPSCs adhesion and mobility on collagen. Conclusions: Our results demonstrate that activated pancreatic stellate cells within PDAC secrete lumican under the negative control of TGF-β; once secreted, the extracellular lumican enhances stellate cell adhesion and mobility in a collagen-rich environment. Clin Cancer Res; 22(19); 4934–46. ©2016 AACR.

Abstract Purpose: To evaluate the relevance between lumican expression patterns and the clinical course of patients with pancreatic ductal adenocarcinoma (PDAC), and to investigate the role of lumican in PDAC progression. Experimental Design: One hundred thirty-one patient tumors were chosen for tissue microarray staining, and Cox regression analysis was used to test the associations between lumican expression and clinical, pathologic, and oncologic outcomes in all patients. Primary PDAC cells and recombinant human lumican protein were used to establish a working model to mimic the in vivo interactions between stromal lumican and PDAC cells. Using this model, we tested the effects of lumican on EGFR signaling via Akt and hypoxia-inducible factor-1α (HIF1α) and its subsequent influence on glucose consumption, lactate production, intracellular ATP, and apoptotic cell death. Results: Lumican was present in the stroma surrounding PDAC cells in roughly one-half of primary tumors and the direct xenografts. Patients with stromal lumican were associated with a profound reduction in metastatic recurrence after surgery and 3-fold longer survival than patients without stromal lumican. In PDAC cells, extracellular lumican reduced EGFR expression and phosphorylation through enhanced dimerization and internalization of EGFR and the resultant inhibition of Akt kinase activity. Lumican also reduced HIF1α expression and activity via Akt. PDAC cells with enhanced HIF1α activity were resistant to lumican-induced inhibition of glucose consumption, lactate production, intracellular ATP, and apoptosis. Conclusions: There is a positive association between stromal lumican in primary PDAC tumors and prolonged survival after tumor resection. Lumican plays a restrictive role in EGFR-expressing pancreatic cancer progression. Clin Cancer Res; 20(24); 6529–40. ©2014 AACR.