Neighbor-specific gene expression revealed from physically interacting cells during mouse embryonic development.

Development of multicellular organisms is orchestrated by persistent cell-cell communication between neighboring partners. Direct interaction between different cell types can induce molecular signals that dictate lineage specification and cell fate decisions. Current single-cell RNA-seq technology cannot adequately analyze cell-cell contact-dependent gene expression, mainly due to the loss of spatial information. To overcome this obstacle and resolve cell-cell contact-specific gene expression during embryogenesis, we performed RNA sequencing of physically interacting cells (PIC-seq) and assessed them alongside similar single-cell transcriptomes derived from developing mouse embryos between embryonic day (E) 7.5 and E9.5. Analysis of the PIC-seq data identified gene expression signatures that were dependent on the presence of specific neighboring cell types. Our computational predictions, validated experimentally, demonstrated that neural progenitor (NP) cells upregulate Lhx5 and Nkx2-1 genes, when exclusively interacting with definitive endoderm (DE) cells. Moreover, there was a reciprocal impact on the transcriptome of DE cells, as they tend to upregulate Rax and Gsc when in contact with NP cells. Using individual cell transcriptome data, we formulated a means of computationally predicting the impact of one cell type on the transcriptome of its neighboring cell types. We have further developed a distinctive spatial-t-distributed stochastic neighboring embedding to display the pseudospatial distribution of cells in a 2-dimensional space. In summary, we describe an innovative approach to study contact-specific gene regulation during embryogenesis.

Calcium channel blockers potentiate gemcitabine chemotherapy in pancreatic cancer.

There is currently no effective treatment for pancreatic ductal adenocarcinoma (PDAC). While palliative chemotherapy offers a survival benefit to most patients, nearly all will eventually progress on treatment and long-term survivability remains poor. Given the lack of subsequent line treatment options, in this study, we sought to identify novel strategies to prevent, delay, or overcome resistance to gemcitabine, one of the most widely used medications in PDAC. Using a combination of single-cell RNA sequencing and high-throughput proteomic analysis, we identified a subset of gemcitabine-resistant tumor cells enriched for calcium/calmodulin signaling. Pharmacologic inhibition of calcium-dependent calmodulin activation led to the rapid loss of drug-resistant phenotypes in vitro, which additional single-cell RNA sequencing identified was due to impaired activation of the RAS/ERK signaling pathway. Consistent with these observations, calcium chelation or depletion of calcium in the culture media also impaired ERK activation in gemcitabine-resistant cells, and restored therapeutic responses to gemcitabine in vitro. We observed similar results using calcium channel blockers (CCBs) such as amlodipine, which inhibited prosurvival ERK signaling in vitro and markedly enhanced therapeutic responses to gemcitabine in both orthotopic xenografts and transgenic models of PDAC. Combined, these results offer insight into a potential means of gemcitabine resistance and suggest that select CCBs may provide a clinical benefit to PDAC patients receiving gemcitabine-based chemotherapy.

XP-524 is a dual-BET/EP300 inhibitor that represses oncogenic KRAS and potentiates immune checkpoint inhibition in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is associated with extensive dysregulation of the epigenome and epigenetic regulators, such as bromodomain and extraterminal motif (BET) proteins, have been suggested as potential targets for therapy. However, single-agent BET inhibition has shown poor efficacy in clinical trials, and no epigenetic approaches are currently used in PDAC. To circumvent the limitations of the current generation of BET inhibitors, we developed the compound XP-524 as an inhibitor of the BET protein BRD4 and the histone acetyltransferase EP300/CBP, both of which are ubiquitously expressed in PDAC tissues and cooperate to enhance tumorigenesis. XP-524 showed increased potency and superior tumoricidal activity than the benchmark BET inhibitor JQ-1 in vitro, with comparable efficacy to higher-dose JQ-1 combined with the EP300/CBP inhibitor SGC-CBP30. We determined that this is in part due to the epigenetic silencing of KRAS in vitro, with similar results observed using ex vivo slice cultures of human PDAC tumors. Accordingly, XP-524 prevented KRAS-induced, neoplastic transformation in vivo and extended survival in two transgenic mouse models of aggressive PDAC. In addition to the inhibition of KRAS/MAPK signaling, XP-524 also enhanced the presentation of self-peptide and tumor recruitment of cytotoxic T lymphocytes, though these lymphocytes remained refractory from full activation. We, therefore, combined XP-524 with an anti-PD-1 antibody in vivo, which reactivated the cytotoxic immune program and extended survival well beyond XP-524 in monotherapy. Pending a comprehensive safety evaluation, these results suggest that XP-524 may benefit PDAC patients and warrant further exploration, particularly in combination with immune checkpoint inhibition.

CellNeighborEX: deciphering neighbor-dependent gene expression from spatial transcriptomics data.

Cells have evolved their communication methods to sense their microenvironments and send biological signals. In addition to communication using ligands and receptors, cells use diverse channels including gap junctions to communicate with their immediate neighbors. Current approaches, however, cannot effectively capture the influence of various microenvironments. Here, we propose a novel approach to investigate cell neighbor-dependent gene expression (CellNeighborEX) in spatial transcriptomics (ST) data. To categorize cells based on their microenvironment, CellNeighborEX uses direct cell location or the mixture of transcriptome from multiple cells depending on ST technologies. For each cell type, CellNeighborEX identifies diverse gene sets associated with partnering cell types, providing further insight. We found that cells express different genes depending on their neighboring cell types in various tissues including mouse embryos, brain, and liver cancer. Those genes are associated with critical biological processes such as development or metastases. We further validated that gene expression is induced by neighboring partners via spatial visualization. The neighbor-dependent gene expression suggests new potential genes involved in cell-cell interactions beyond what ligand-receptor co-expression can discover.

A Gravid Situation: General Surgery Faculty Support for Pregnant Surgical Residents.

INTRODUCTION: The perceptions of teaching faculty toward pregnant general surgery residents have been overlooked despite the daily interactions amongst these groups. METHODS: A 32-question survey designed to measure general surgery teaching faculty perceptions toward pregnant residents was distributed electronically from March 2022 to April 2022 to general surgery teaching faculty in the United States. Descriptive statistics were used to characterize responses and differences in perceptions, and qualitative analysis identified recurring themes from free-text responses. RESULTS: Among 163 respondents included in the final analysis, 58.5% were male and 41.5% were female. Despite 99.4% of surgeons feeling comfortable if a resident told them they were pregnant, 22.4% of surgeons disagreed that their institutions have supportive cultures toward pregnancy. Almost half (45.4%) have witnessed negative comments about pregnant residents and half (50.3%) believe that pregnant surgical residents are discriminated against by their coresidents. Nearly two-thirds of surgeons (64.8%) believe that someone should have a child whenever they wish during training. Given recent reports, 80.2% of surgeons recognized that female surgeons have increased risks of infertility and pregnancy complications. Recurring themes of normalizing pregnancy, improving policies, and creating a culture change were expressed. CONCLUSIONS: In this national survey, although there appears to be positive perceptions of pregnancy in surgical training amongst those surveyed, there is acknowledged necessity of further normalizing pregnancy and improving policies to better support pregnant residents. These data provide further evidence that though perceptions may be improving, changes are still needed to better support pregnancy during training.

Racial/Ethnic Disparities in the Era of Minimally Invasive Surgery for Treatment of Colorectal Cancer.

BACKGROUND: Minimally invasive (laparoscopic and robotic) surgery (MIS) for colorectal cancer is associated with improved outcomes. We sought to characterize possible disparities in surgical approach and outcomes. PATIENTS AND METHODS: In this cross-sectional study, colorectal adenocarcinoma cases among non-Hispanic white (NHW), non-Hispanic Black (NHB), and Hispanic patients were identified using the National Cancer Database (2010-2017). Logistic and Poisson regressions, generalized logit models, and Cox proportional hazards were used to assess outcomes, with reclassification of surgery type if converted to open. RESULTS: NHB patients were less likely to undergo robotic surgery. After multivariable analysis, NHB patients were 6% less likely, while Hispanic patients were 12% more likely to undergo a MIS approach. Lymph node retrieval was higher (> 1.3% more, p < 0.0001) and length of stay was shorter (> 17% shorter, p < 0.0001) for MIS approaches. Unplanned readmission was lower for MIS colon cancer operations compared with open operations, but not for rectal cancer. Race/ethnicity-adjusted risk of death was lower with MIS approaches for colon as well as rectal cancer. After adjusting for surgery type, risk of death was 12% lower for NHB and 35% lower for Hispanic patients compared with NHW patients. Hispanic patients had 21% lower risk of death, while NHB patients had 12% higher risk of death than NHW patients with rectal cancer, after adjusting for surgery type. CONCLUSIONS: Racial/ethnic disparities exist in utilization of MIS for colorectal cancer treatment, disproportionately affecting NHB patients. Since MIS has the potential to improve outcomes, suboptimal access may contribute to harmful and thus unacceptable disparities in survivorship.

Biological evaluation of novel gemcitabine analog in patient-derived xenograft models of pancreatic cancer.

Gemcitabine (Gem) has been a standard first-line drug for pancreatic cancer (PCa) treatment; however, Gem's rapid metabolism and systemic instability (short half-life) limit its clinical outcome. The objective of this study was to modify Gem into a more stable form called 4-(N)-stearoyl-gemcitabine (4NSG) and evaluate its therapeutic efficacy in patient-derived xenograft (PDX) models from PCa of Black and White patients.Methods 4NSG was synthesized and characterized using nuclear magnetic resonance (NMR), elemental analysis, and high-performance liquid chromatography (HPLC). 4NSG-loaded solid lipid nanoparticles (4NSG-SLN) were developed using the cold homogenization technique and characterized. Patient-derived pancreatic cancer cell lines labeled Black (PPCL-192, PPCL-135) and White (PPCL-46, PPCL-68) were used to assess the in vitro anticancer activity of 4NSG-SLN. Pharmacokinetics (PK) and tumor efficacy studies were conducted using PDX mouse models bearing tumors from Black and White PCa patients.Results 4NSG was significantly stable in liver microsomal solution. The effective mean particle size (hydrodynamic diameter) of 4NSG-SLN was 82 ± 6.7 nm, and the half maximal inhibitory concentration (IC50) values of 4NSG-SLN treated PPCL-192 cells (9 ± 1.1 µM); PPCL-135 (11 ± 1.3 µM); PPCL-46 (12 ± 2.1) and PPCL-68 equaled to 22 ± 2.6 were found to be significantly lower compared to Gem treated PPCL-192 (57 ± 1.5 µM); PPCL-135 (56 ± 1.5 µM); PPCL-46 (56 ± 1.8 µM) and PPCL-68 (57 ± 2.4 µM) cells. The area under the curve (AUC), half-life, and pharmacokinetic clearance parameters for 4NSG-SLN were 3-fourfold higher than that of GemHCl. For in-vivo studies, 4NSG-SLN exhibited a two-fold decrease in tumor growth compared with GemHCl in PDX mice bearing Black and White PCa tumors.Conclusion 4NSG-SLN significantly improved the Gem's pharmacokinetic profile, enhanced Gem's systemic stability increased its antitumor efficacy in PCa PDX mice bearing Black and White patient tumors.

The impact of race/ethnicity on pancreaticoduodenectomy outcomes for pancreatic cancer.

PURPOSE: To investigate the impact of race/ethnicity on surgical outcomes following pancreaticoduodenectomy for pancreatic cancer. METHODS: A retrospective review of patients undergoing pancreaticoduodenectomy for adenocarcinoma in the National Surgical Quality Improvement Program (NSQIP) database from 2014 to 2019. Patient and tumor characteristics and 30-day postoperative outcomes were compared. Multivariable logistic and linear regression models were conducted to investigate the relationship between race/ethnicity and surgical outcomes. RESULTS: Six thousand five hundred and sixty-two patients were included (84.5% White, 7.9% Black, 3% Hispanic, 4.6% Asian). Larger proportions of Blacks had preoperative American Society of Anesthesiologists class 3 or 4. There were no significant differences in tumor characteristics or operative techniques. A smaller proportion of Asians and Hispanics received neoadjuvant chemotherapy and/or radiation than Blacks and Whites. Relative to White, the Black race was independently associated with postoperative sepsis and reoperation. Both Black and Hispanic race/ethnicity were associated with prolonged intubation and delayed gastric emptying, and minorities races/ethnicities were associated with longer length of hospital stay. Relative to White, Hispanic, and Asian race/ethnicity were independently associated with a lower likelihood of neoadjuvant therapy (NAT) receipt. CONCLUSION: In ACS-NSQIP participating hospitals, non-White race/ethnicity was independently associated with adverse outcomes after pancreatic cancer resection. A possible disparity in NAT receipt may exist in Asian and Hispanic patients undergoing surgical resection.

General Surgery Faculty Knowledge and Perceptions of Breast Pumping Amongst Postpartum Surgical Residents.

BACKGROUND: There is a lack of data regarding the knowledge and perceptions teaching faculty possess about breast pumping among general surgery residents despite breast pumping becoming more common during training. This study aimed to examine faculty knowledge and perceptions of breast pumping amongst general surgery residents. METHODS: A 29-question survey measuring knowledge and perceptions about breast pumping was administered online to United States teaching faculty from March-April 2022. Descriptive statistics were used to characterize responses, Fisher's exact test was used to report differences in responses by surgeon sex and age, and qualitative analysis identified recurrent themes. RESULTS: 156 responses were analyzed; 58.6% were male and 41.4% were female, and the majority (63.5%) were less than 50 years old. Nearly all (97.7%) women with children breast pumped, while 75.3% of men with children had partners who pumped. Men more often than women indicated "I don't know" when asked about frequency (24.7 vs. 7.9%, p = 0.041) and duration (25.0 vs. 9.5%, p = 0.007) of pumping. Nearly all surgeons are comfortable (97.4%) discussing lactation needs and support (98.1%) breast pumping, yet only two-thirds feel their institutions are supportive. Almost half (41.0%) of surgeons agreed that breast pumping does not impact operating room workflow. Recurring themes included normalizing breast pumping, creating change to better support residents, and communicating needs between all parties. CONCLUSIONS: Teaching faculty may have supportive perceptions about breast pumping, but knowledge gaps may hinder greater levels of support. Opportunities exist for increased faculty education, communication, and policies to better support breast pumping residents.

Synthesis, characterization, and anticancer evaluation of 1,3-bistetrahydrofuran-2yl-5-FU as a potential agent for pancreatic cancer.

The failure of current chemotherapeutic agents for pancreatic cancer (PCa) makes it the most aggressive soft tissue tumor with a 5-year survival of slightly above 10% and is estimated to be the second leading cause of cancer death by 2030. OBJECTIVE: The main aim was to synthesize, characterize and evaluate the anticancer activity of 1,3-bistetrahydrofuran-2yl-5FU (MFU). METHODS: MFU was synthesized by using 5-fluorouracil (5-FU) and tetrahydrofuran acetate, and characterized by nuclear magnetic resonance (NMR), micro-elemental analysis, high-performance liquid chromatography (HPLC), and liquid chromatography with mass spectrophotometry (LC-MS). MFU and Gemcitabine hydrochloride (GemHCl) were tested for antiproliferative activity against MiaPaca-2 and Panc-1 cell lines. RESULTS: The half-minimum inhibitory concentration (IC50) of MFU was twice lower than that of GemHCl when used in both cell lines. MiaPaca-2 cells (MFU-IC50 = 4.5 ± 1.2 µM vs. GemHCl-IC50 = 10.3 ± 1.1 µM); meanwhile similar trend was observed in Panc-1 cells (MFU-IC50 = 3.0 ± 1 µM vs. GemHCl-IC50 = 6.1 ± 1.03 µM). The MFU and GemHCl effects on 3D spheroids showed a similar trend (IC50-GemHCl = 14.3 ± 1.1 µM vs. IC50-MFU = 7.2 ± 1.1 µM) for MiaPaca-2 cells, and (IC50-GemHCl = 16.3 ± 1.1 µM vs. IC50-MFU = 9.2 ± 1.1 µM) for Panc-1 cells. MFU significantly inhibited clonogenic cell growth, and induced cell death via apoptosis. Cell cycle data showed mean PI for GemHCl (48.5-55.7) twice higher than MFU (24.7 to 27.9) for MiaPaca-2 cells, and similarly to Panc-1 cells. The in-vivo model showed intensely stained EGFR (stained brown) in all control, GemHCl and MFU-treated mice bearing subcutaneous PDX tumors, however, HER2 expression was less stained in MFU-treated tumors compared to GemHCl-treated tumors and controls. Mean tumor volume of MFU-treated mice (361 ± 33.5 mm3) was three-fold lower than GemHCl-treated mice (1074 ± 181.2 mm3) bearing pancreatic PDX tumors. CONCLUSION: MFU was synthesized with high purity and may have potential anticancer activity against PCa.

Phase II Study of 5-Fluorouracil, Oxaliplatin plus Dasatinib (FOLFOX-D) in First-Line Metastatic Pancreatic Adenocarcinoma.

LESSONS LEARNED: Preclinical studies have demonstrated that Src inhibition through dasatinib synergistically enhances the antitumor effects of oxaliplatin. In this phase II, single-arm study, FOLFOX with dasatinib in previously untreated patients with mPC only showed only modest clinical activity, with a progressive-free survival of 4 months and overall survival of 10.6 months. Continued investigation is ongoing to better understand the role of Src inhibition with concurrent 5-fluorouracil and oxaliplatin in a subset of exceptional responders. BACKGROUND: Src tyrosine kinase activity is overexpressed in many human cancers, including metastatic pancreatic cancer (mPC). Dasatinib is a potent inhibitor of Src family of tyrosine kinases. This study was designed to investigate whether dasatinib can synergistically enhance antitumor effects of FOLFOX regimen (FOLFOX-D). METHODS: In this single-arm, phase II study, previously untreated patients received dasatinib 150 mg oral daily on days 1-14, oxaliplatin 85 mg/m2 intravenous (IV) on day 1 every 14 days, leucovorin (LV) 400 mg/m2 IV on day 1 every 14 days, 5-fluorouracil (5-FU) bolus 400 mg/m2 on day 1 every 14 days, and 5-FU continuous infusion 2,400 mg/m2 on day 1 every 14 days. Primary endpoint was progression-free survival (PFS) with preplanned comparison to historical controls. RESULTS: Forty-four patients enrolled with an estimated median PFS of 4.0 (95% confidence interval [CI], 2.3-8.5) months and overall survival (OS) of 10.6 (95% CI, 6.9-12.7) months. Overall response rate (ORR) was 22.7% (n = 10): one patient (2.3%) with complete response (CR) and nine patients (20.5%) with partial response (PR). Fifteen patients (34.1%) had stable disease (SD). Nausea was the most common adverse event (AE) seen in 35 patients (79.5%). CONCLUSION: The addition of dasatinib did not appear to add incremental clinical benefit to FOLFOX in untreated patients with mPC.

It's more than just cancer biology: Health disparities in patients with pancreatic neuroendocrine tumors.

BACKGROUND AND OBJECTIVES: Pancreatic neuroendocrine tumors (PNETs) represent a rare form of pancreatic cancer. Racial/ethnic disparities have been documented in pancreatic ductal adenocarcinoma, but health disparities have not been well described in patients with PNETs. METHODS: A retrospective review of patients with PNETs in the National Cancer Database was performed for 2004-2014. Approximately 16 605 patients with PNETs and available vital status were identified. Survival was compared by race/ethnicity and socioeconomic status using Kaplan-Meier methods and Cox regression. RESULTS: There were no significant differences in survival between Non-Hispanic, White; Hispanic, White; or Non-Hispanic, Black patients on univariate analysis. Kaplan-Meier analysis showed that patients from communities with lower median household income and education level had worse survival (p < 0.001). Patients age less than 65 without insurance, similarly, had worse survival (p < 0.001). Multivariable modeling found no association between race/ethnicity and risk of mortality (p = 0.37). Lower median household income and lower education level were associated with increased mortality (p < 0.001). CONCLUSIONS: Unlike most other malignancies, race/ethnicity is not associated with survival differences in patients with PNETs. Patients with lower socioeconomic status had worse survival. The presence of identifiable health disparities in patients with PNETs represents a target for intervention and opportunity to improve survival in patients with this malignancy.

Biliary intervention rates during neoadjuvant therapy for adenocarcinoma of the pancreatic head.

BACKGROUND: Neoadjuvant therapy prior to resection of adenocarcinoma of the pancreatic head increases time to surgery and thus the possibility of biliary complications. We hypothesized that biliary complications during neoadjuvant therapy negatively impact clinical outcomes. METHODS: We completed a retrospective study of a cohort of borderline resectable patients consistently treated with neoadjuvant therapy from May 2014 through March 2019. Biliary complications were defined as new-onset biliary obstruction, existing stent failure, cholecystitis, and cholangitis. RESULTS: Of 59 patients that met inclusion criteria, 34 (57.6%) went on to resection. Biliary complications affected 16 patients (27%); 8 (50%) of these patients went on to surgical resection. Of those 43 patients who did not have a biliary intervention, 26 went on to surgical resection (60.4%). There was no significant effect of a biliary complication on total number of chemotherapy cycles (p = 0.12), proceeding to surgical resection (p = 0.56) or on median survival (p = 0.23). Among patients who did proceed to surgery, there was a notable difference in median survival for patients who required a biliary intervention (17.9 vs 31.0 months) that did not reach significance (p = 0.35). CONCLUSION: The need for further biliary interventions during neoadjuvant therapy for pancreatic adenocarcinoma is common, but does not appear to have a significant effect on number of cycles of neoadjuvant therapy or proceeding to surgical resection. Larger studies are necessary to determine if these events compromise overall survival.

Cytotoxic effects of gemcitabine-loaded solid lipid nanoparticles in pancreatic cancer cells.

This study investigated the cytotoxic effects of gemcitabine-loaded solid lipid nanoparticle (Gem-SLN) on the patient-derived primary pancreatic cancer cell lines (PPCL-46) and MiaPaCa-2. Different SLN formulations were prepared from glyceryl monostearate (GMS), polysorbate 80 (Tween® 80) and poloxamer 188 (Pol 188) as surfactants using a cold homogenization method. Gem-SLN was characterized for particle size and charge distribution, entrapment efficiency and loading capacity. Fourier Transform Infra-Red (FTIR) spectroscopy was used to verify Gem and SLN interaction while differential scanning calorimetry (DSC) was used to acquire thermodynamic information on Gem-SLN. Cytotoxicity studies was conducted on PPCL-46 cells and Mia-PaCa-2 cells. Among the different Gem-SLN formulations prepared, Gem-SLN15 was selected based on entrapment efficiency (EE) of Gem, loading efficiency of Gem, cytotoxicity and rate of Gem release. Growth inhibition of Gem-SLN15-treated PPCL-46 culture (IC50 (2D) =27± 5 µM; IC50 (3D) = 66 ± 2 µM) was remarkably higher than gemcitabine hydrochloride (GemHCl)-treated PPCL-46 culture (IC50 (2D) =126±3 µM; IC50 (3D) =241±3 µM). Similar trend of higher Gem-SLN15 inhibition in MiaPaCa-2 culture was found (IC50 (2D) =56±16 µM; IC50 (3D) =127±4 µM) compared with GemHCl-treated Mia-PaCa-2 culture (IC50 (2D) =188±46 µM; IC50 (3D) =254±52 µM). The anticancer activity of Gem-SLN15 was significantly more effective than GemHCl in PPCL-46 compared to Mia-PaCa-2 cancer cells. Schematic diagram for preparation of Gem-SLN through cold homogenization and methods for characterization and in-vitro studies.

Development of apratoxin S10 (Apra S10) as an anti-pancreatic cancer agent and its preliminary evaluation in an orthotopic patient-derived xenograft (PDX) model.

Despite the significant progress in the field of cancer therapeutics, the incidence of pancreatic cancer (PC) has continuously increased. One possible mechanism for this increasing burden is impaired drug delivery and drug resistance resulting from a unique tumor microenvironment and genetic mutations. Apratoxins are potent anticancer agents and cotranslational translocation inhibitors with potential therapeutic applications to treat cancers with active secretory pathways. Here, we developed apratoxin S10 (Apra S10) as an anti-pancreatic cancer agent which potently inhibited the growth of both established and patient-derived primary pancreatic cancer cells. We validated its mechanism of action on pancreatic cancer cells by demonstrating the downregulation of multiple receptor tyrosine kinases and inhibition of growth factor and cytokine secretion. Apra S10 also inhibited a number of cytokines secreted by stromal cells, suggesting that Apra S10 not only inhibited pancreatic cancer cell secretion, but also reduced the level of factors secreted by other cell types active within the tumor microenvironment. As Apra S10 tissue distribution indicated its high enrichment in pancreas tissue, an orthotopic pancreatic patient-derived xenograft mouse model that closely mimics the human pancreatic tumor microenvironment was for the first time used in apratoxin studies. Apra S10 showed promising antitumor effect in this pancreatic cancer model and this effect was mediated through anti-proliferation properties.

Gastric Plexiform Fibromyxoma: A Great Mimic of Gastrointestinal Stromal Tumor (GIST) and Diagnostic Pitfalls.

Through a multicenter study, we collected seven cases of gastric plexiform fibromyxoma including four females and three males, 21 to 79 y old (46.1 ± 10.1). All cases showed a unilocular lesion measuring 0.3 to 17 cm (5.3 ± 2.4), arising from antrum (5/7) or body (2/7). Six of the seven cases had intraoperative frozen sections and/or endoscopic ultrasound fine needle aspiration (EUS-FNA), and all of them were preoperatively or intraoperatively diagnosed as gastrointestinal stromal tumor (GIST). EUS-FNA material showed markedly elongated spindle cells with streaming oval to elongated nuclei with rounded ends. Histologically, the tumors exhibited a plexiform growth pattern and were composed of a rich myxoid stroma and cytologically bland uniform spindle cells without mitotic figures, with the exception of one case which displayed nuclear pleomorphism and increased mitosis. Immunostains showed the tumor cells to be focally positive for SMA (6/6), focally and weakly positive for desmin (3/6) and caldesmon (2/3), negative for CD117 (0/7), CD34 (0/7), DOG1 (0/4), and S100 (0/5). No mutations were identified on Next-Generation Sequencing test, and no loss of SDHB immunoreactivity was identified in the tumor with nuclear pleomorphism. One case was treated with Gleevec because of the initial diagnosis of GIST. All patients had a follow-up for up to 11 y, with no tumor recurrence or metastasis reported. Our results suggest that gastric plexiform fibromyxoma is rare and may be underrecognized and misinterpreted as GIST during intraoperative frozen section or preoperative EUS-FNA diagnosis without immunostains leading to inappropriate treatment.

A quantitative alternative to the Goutallier classification system using Lava Flex and Ideal MRI techniques: volumetric intramuscular fatty infiltration of the supraspinatus muscle, a cadaveric study.

OBJECTIVE: The Goutallier classification system is the most commonly used method for grading intramuscular fatty infiltration in rotator cuff tears. This grading system presents low inter-observer reliability and an inability to provide quantitative and repeatable outcomes for intramuscular fat. We determined the correlation and reliability of two methods, the Lava Flex and Ideal IQ MRI techniques, in quantifying volumetric intramuscular fat, while also comparing to the Goutallier method. MATERIALS AND METHODS: The supraspinatus muscles of seventeen cadaveric shoulders were scanned using the Lava Flex and Ideal IQ MRI imaging protocols. Histological analysis was performed on the same muscles. Agreement, reliability, and correlation analyses were performed to compare all outcomes. RESULTS: The Lava Flex protocol took an average of ~ 4 min, while the Ideal IQ required about ~ 11 min to complete. Bland-Altman analysis showed good agreement between the Lava Flex and Ideal IQ [LOA (- 0.10 and 0.05)], and ICC analyses showed excellent reliability (ICC (1,1) 0.948; ICC (2,1) 0.947). There was a 91% correlation between the Lava Flex and Ideal IQ MR protocols. Weighted Kappa analysis between histology and the Goutallier classification showed fair-to-moderate agreement. DISCUSSION: The Lava Flex technique, taking about 30% of the acquisition time, may prevent motion artifacts in outcomes associated with the longer Ideal IQ technique. However, potential magnetic field inhomogeneities should be considered. The Lava Flex technique may be a faster and valid alternative to the Goutallier classification system.

The Microbiota and Cancer Cachexia.

Cancer cachexia is a multifactorial syndrome defined by weight loss, muscle wasting, and systemic inflammation. It affects the majority of patients with advanced cancer and is associated with poor treatment response, early mortality and decreased quality of life. The microbiota has been implicated in cancer cachexia through pathways of systemic inflammation, gut barrier dysfunction and muscle wasting. The imbalance of the microbiota, known as dysbiosis, has been shown to influence cancer cachexia. Bacteria that play beneficial and detrimental roles in the disease pathogenesis have been identified. The phenotype of cancer cachexia is associated with decreased levels of Lactobacillales and increased levels of Enterobacteriaceae and Parabacteroides. Currently, there are no treatment options that demonstrate increased survival or the quality of life in patients suffering from cancer cachexia. Through the manipulation of beneficial bacteria in the gut microbiota, different treatment options have been explored. Prebiotics and probiotics have been shown to improve outcomes in animal models of cachexia. Expounding on this mechanism, fecal microbiota transplant (FMT) holds promise for a future treatment of cancer cachexia. Further research is necessary to address this detrimental disease process and improve the lives of patients suffering from cancer cachexia.

Aberrant expression of PDZ-binding kinase/T-LAK cell-originated protein kinase modulates the invasive ability of human pancreatic cancer cells via the stabilization of oncoprotein c-MYC.

High frequency of mortality in patients with pancreatic ductal adenocarcinoma (PDAC) is vastly associated with the invasive and metastatic nature of these cancer cells. Little is known about the factors involved in this invasive/metastatic process. The current challenge in the treatment of these patients is the lack of viable options besides gemcitabine. The aim of this study was to evaluate the role of PDZ-binding kinase (PBK)/T-LAK cell-originated protein kinase (TOPK) in invasive PDAC cells and to determine whether PBK/TOPK expression drives invasiveness in PDAC. Using gain-of-function and loss-of-function studies in established and patient-derived xenograft-PDAC cell lines, and examining patient-derived archival tissue samples, we demonstrate for the first time that PBK/TOPK is upregulated in pancreatic cancer and expression levels are closely associated with the invasive property of pancreatic cancer cells. Modulation of PBK/TOPK causally regulates the invasive ability of PDAC cells. We also demonstrate that two key players in metastatic invasion, matrix metalloproteinases-2 (MMP-2) and MMP-9 gelatinase activity and gene promoter activities, are regulated by PBK/TOPK. Moreover, we demonstrate for the first time that PBK/TOPK provides stability of an oncoprotein, c-MYC, which transcriptionally regulates MMP-2 and MMP-9 in these invasive PDAC cells. Our in vitro and in situ data corroborate that PBK/TOPK is closely associated with the invasive nature of PDAC and reveal a novel mechanism by which the metastatic behavior of human pancreatic cancer cells is regulated. These findings provide a rationale for targeting PBK/TOPK for the therapeutic intervention of invasive/metastatic pancreatic cancer in human.

Intestinal microbiota enhances pancreatic carcinogenesis in preclinical models.

Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer death in the United States yet data are scant regarding host factors influencing pancreatic carcinogenesis. Increasing evidence support the role of the host microbiota in carcinogenesis but its role in PDAC is not well established. Herein, we report that antibiotic-mediated microbial depletion of KrasG12D/PTENlox/+ mice showed a decreased proportion of poorly differentiated tumors compared to microbiota-intact KrasG12D/PTENlox/+ mice. Subsequent 16S rRNA PCR showed that ~50% of KrasG12D/PTENlox/+ mice with PDAC harbored intrapancreatic bacteria. To determine if a similar observation in humans correlates with presence of PDAC, benign and malignant human pancreatic surgical specimens demonstrated a microbiota by 16S bacterial sequencing and culture confirmation. However, the microbial composition did not differentiate PDAC from non-PDAC tissue. Furthermore, murine pancreas did not naturally acquire a pancreatic microbiota, as germ-free mice transferred to specific pathogen-free housing failed to acquire intrapancreatic bacteria over time, which was not augmented by a murine model of colitis. Finally, antibiotic-mediated microbial depletion of Nod-SCID mice, compared to microbiota-intact, showed increased time to PDAC xenograft formation, smaller tumors, and attenuated growth. Interestingly, both xenograft cohorts were devoid of intratumoral bacteria by 16S rRNA PCR, suggesting that intrapancreatic/intratumoral microbiota is not the sole driver of PDAC acceleration. Xenografts from microbiota-intact mice demonstrated innate immune suppression by immunohistochemistry and differential regulation of oncogenic pathways as determined by RNA sequencing. Our work supports a long-distance role of the intestinal microbiota on PDAC progression and opens new research avenues regarding pancreatic carcinogenesis.