Richard Sleightholm

Emerging roles of the CXCL12/CXCR4 axis in pancreatic cancer progression and therapy

ABSTRACT Chemokine networks regulate a variety of cellular, physiological, and immune processes. These normal functions can become appropriated by cancer cells to facilitate a more hospitable niche for aberrant cells by enhancing growth, proliferation, and metastasis. This is especially true in pancreatic cancer, where chemokine signaling is a vital component in the development of the supportive tumor microenvironment and the signaling between the cancer cells and surrounding stromal cells. Although expression patterns vary among cancer types, the chemokine receptor CXCR4 has been implicated in nearly every major malignancy and plays a prominent role in pancreatic cancer development and progression. This receptor, in conjunction with its primary chemokine ligand CXCL12, promotes pancreatic cancer development, invasion, and metastasis through the management of the tumor microenvironment via complex crosstalk with other pathways. Thus, CXCR4 likely contributes to the poor prognoses observed in patients afflicted with this malignancy. Recent exploration of combination therapies with CXCR4 antagonists have demonstrated improved outcomes, and abolishing the contribution of this pathway may prove crucial to effectively treat pancreatic cancer at both the primary tumor and metastases.

Polymeric chloroquine as an inhibitor of cancer cell migration and experimental lung metastasis.

Chloroquine (CQ) is a widely used antimalarial drug with emerging potential in anticancer therapies due to its apparent inhibitory effects on CXCR4 chemokine receptor, autophagy, and cholesterol metabolism. This study reports on polymeric CQ (pCQ) as a macromolecular drug with antimetastatic activity. The pCQ polymers were synthesized by copolymerization of methacryloylated hydroxy-CQ (HCQ) and N-(2-hydroxypropyl)methacrylamide (HPMA). The results show that pCQ is significantly more effective in inhibiting cancer cell migration and invasion when compared with the parent HCQ. The proposed mechanism of action at least partially relies on the ability of pCQ to inhibit cell migration mediated by the CXCR4/CXCL12 pathway. The pCQ also demonstrates superior inhibitory activity over HCQ when tested in a mouse model of experimental lung metastasis. Lastly, pCQ shows the ability to efficiently translocate to the cytoplasm while exhibiting lower cytotoxicity than HCQ. Overall, this study supports pCQ as a promising polymeric drug platform suitable for use in combination antimetastatic strategies and potential use in cytoplasmic drug delivery.

The American Society of Peritoneal Surface Malignancies Multi-Institution evaluation of 1,051 advanced ovarian cancer patients undergoing cytoreductive surgery and HIPEC: An introduction of the peritoneal surface disease severity score

Standard treatment for ovarian epithelial cancer (OEC) consists of cytoreductive surgery (CRS) and a platinum–taxane chemotherapy combination. There is increasing interest in evaluating hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with stage IIIC/IV disease. The peritoneal surface disease severity score (PSDSS) was introduced as a basis to improve patient selection for this therapy in OEC.

Chloroquine-Modified Hydroxyethyl Starch as a Polymeric Drug for Cancer Therapy

Hydroxyethyl starch (HES) is a clinically used polysaccharide colloidal plasma volume expander. The goal of this study was to synthesize HES modified with hydroxychloroquine (HCQ) as a novel polymeric drug with the ability to inhibit the invasive character of pancreatic cancer (PC) cells. HES was conjugated with HCQ using a simple carbonyldiimidazole coupling to prepare Chloroquine-modified HES (CQ-HES). CQ-HES with various degrees of HCQ substitution were synthesized and characterized. Atomic force microscopy was used to demonstrate a pH-dependent assembly of CQ-HES into well-defined nanoparticles. In vitro studies in multiple PC cell lines showed CQ-HES to have a similar toxicity profile as HCQ. Confocal microscopy revealed the propensity of CQ-HES to localize to lysosomes and mechanistic studies confirmed the ability of CQ-HES to inhibit autophagy in PC cells. Further studies demonstrated a greatly enhanced ability of CQ-HES to inhibit the migration and invasion of PC cells when compared with HCQ. The enhanced inhibitory actions of CQ-HES compared to HCQ appeared to arise in part from the increased inhibition of ERK and Akt phosphorylation. We found no significant HCQ release from CQ-HES, which confirmed that the observed activity was due to the action of CQ-HES as a polymeric drug. Due to its promising ability to block cancer cell invasion and the ability to form nanoparticles, CQ-HES has the potential as a drug delivery platform suitable for future development with chemotherapeutics to establish novel antimetastatic treatments.

Massive adrenal vein aneurysm mimicking an adrenal tumor in a patient with hemophilia A: a case report and review of the literature

BackgroundVisceral venous aneurysms are exceedingly rare, and until now, there have been no reports of this phenomenon in the adrenal vasculature. This report details the first adrenal venous aneurysm reported in the literature. The aneurysm presented as an 18-cm mass that was initially suspected to be a hematoma or tumor on the basis of the complex medical history of the patient, which included hemophilia A and testicular cancer. After surgical excision, pathologic examination confirmed this mass to be a 15.9-cm adrenal vein aneurysm, the largest aneurysm of any type or location recorded in the medical literature.Case presentationA 58-year-old caucasian male with hemophilia A presented to the emergency room of another institution with abdominal pain, blood in the stool, and a history of diverticulosis and symptomatic hemorrhoids. A large, left-sided adrenal mass was detected by computed tomography, and because of the patient’s hemophilia A and imaging consistent with a hemorrhagic mass, a hematoma was initially suspected. The patient was transferred to our institution, monitored for further bleeding with a stable hospital course, and discharged from the hospital under close monitoring. After 7–8 weeks with no change in the size of the mass, concerns grew regarding increasing symptoms of both satiety and mass effects from the large anomaly, as well as about the patient’s complicated medical history, which also included cancer. Surgical excision was recommended because of the concerns about increasing symptoms and the possibility of a malignancy. Correction and maintenance of factor VIII levels were incorporated pre-, intra-, and postoperatively, and en bloc surgical resection was performed to minimize bleeding and provide oncologic extirpation of the mass. A bowling ball-sized mass was removed, and careful pathologic examination revealed the mass to be a venous adrenal aneurysm. After a brief hospital stay, the patient made a full recovery. Extensive review of the literature revealed 11 reports of adrenal artery aneurysms but no reported case of an adrenal aneurysm arising from the venous system.ConclusionsSeveral case reports suggest a correlation between hemophilia and aneurysms. In patients with inherited clotting disorders such as hemophilia A, aneurysms may present in atypical fashions and should be carefully ruled out.

Incidence and patterns of locoregional failure after stereotactic body radiation therapy for pancreatic adenocarcinoma

PURPOSE Stereotactic body radiation therapy (SBRT) is increasingly utilized in the neoadjuvant and definitive settings for pancreatic adenocarcinoma. The risk of local and regional recurrence after this treatment remains largely unknown. Because of the lack of elective nodal treatment and high fractional dose, we hypothesized that the incidence of regional out-of-field recurrence would predominate after SBRT. METHODS AND MATERIALS Electronic medical records of all patients treated in our department with SBRT for pancreatic adenocarcinoma were retrospectively reviewed. Patients were separated into those who converted or did not convert to surgical resectability. Demographic, treatment, and outcome data were collected and analyzed. Recurrence was assessed based on the Response Evaluation Criteria In Solid Tumors version 1.1. Treatment plans were reviewed to determine the locations of failure with respect to treatment volume. Statistical comparisons were made using Mann-Whitney U testing for continuous variables and χ2 testing for dichotomous variables. RESULTS Data on 69 patients was available for analysis. After treatment, 18 patients (26.1%) suffered in-field recurrence and 11 patients (15.9%) recurred regionally out of field. The median time to in-field and out-of-field failures were similar at 120.5 and 108.0 days, respectively (P = .65). Of those who failed out-of-field, 4 of 11 patients (36.4%) were without in-field failure prior to death. In-field failure rates were less in patients who subsequently underwent surgical resection compared with those who did not (2 of 22 patients [9.1%] vs 16 of 47 patients [34.0%]; P = .028), but out-of-field recurrence was unaffected by subsequent surgical resection (3 of 22 patients [13.6%] vs 8 of 47 patients [17.0%]; P = .720). All out-of-field failures occurred in areas that received <2600 cGy. CONCLUSIONS The incidence of out-of-field failure remains acceptable after SBRT for pancreatic adenocarcinoma. Despite the high biological equivalent dose allowed by SBRT, in-field control remains problematic and continues to signal relative radiation resistance that is associated with bulky disease.

Simultaneous quantitation of hydroxychloroquine and its metabolites in mouse blood and tissues using LC–ESI–MS/MS: An application for pharmacokinetic studies

Hydroxychloroquine (HCQ) has been shown to disrupt autophagy and sensitize cancer cells to radiation and chemotherapeutic agents. However, the optimal delivery method, dose, and tumor concentrations required for these effects are not known. This is in part due to a lack of sensitive and reproducible analytical methods for HCQ quantitation in small animals. As such, we developed and validated a selective and sensitive liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method for simultaneous quantitation of hydroxychloroquine and its metabolites in mouse blood and tissues. The chromatographic separation and detection of analytes were achieved on a reversed phase Thermo Aquasil C18 (50×4.6mm, 3μ) column, with gradient elution using 0.2% formic acid and 0.1% formic acid in methanol as mobile phase at a flow rate of 0.5mL/min. Simple protein precipitation was utilized for extraction of analytes from the desired matrix. Analytes were separated and quantitated using MS/MS with an electrospray ionization source in positive multiple reaction monitoring (MRM) mode. The MS/MS response was linear over the concentration range from 1 to 2000ng/mL for all analytes with a correlation coefficient (R2) of 0.998 or better. The within- and between-day precision (relative standard deviation, % RSD) and accuracy were within the acceptable limits per FDA guidelines. The validated method was successfully applied to a preclinical pharmacokinetic mouse study involving low volume blood and tissue samples for hydroxychloroquine and metabolites.

WDR5 supports colon cancer cells by promoting methylation of H3K4 and suppressing DNA damage

BackgroundKMT2/MLL proteins are commonly overexpressed or mutated in cancer and have been shown to support cancer maintenance. These proteins are responsible for methylating histone 3 at lysine 4 and promoting transcription and DNA synthesis; however, they are inactive outside of a multi-protein complex that requires WDR5. WDR5 has been implicated in cancer for its role in the COMPASS complex and its interaction with Myc; however, the role of WDR5 in colon cancer has not yet been elucidated.MethodsWDR5 expression was evaluated using RT-qPCR and western blot analysis. Cell viability and colony forming assays were utilized to evaluate the effects of WDR5 depletion or inhibition in colon cancer cells. Downstream effects of WDR5 depletion and inhibition were observed by western blot.ResultsWDR5 is overexpressed in colon tumors and colon cancer cell lines at the mRNA and protein level. WDR5 depletion reduces cell viability in HCT116, LoVo, RKO, HCT15, SW480, SW620, and T84 colon cancer cells. Inhibition of the WDR5:KMT2/MLL interaction using OICR-9429 reduces cell viability in the same panel of cell lines albeit not to the same extent as RNAi-mediated WDR5 depletion. WDR5 depletion reduced H3K4Me3 and increased phosphorylation of H2AX in HCT116, SW620, and RKO colon cancer cells; however, OICR-9429 treatment did not recapitulate these effects in all cell lines potentially explaining the reduced toxicity of OICR-9429 treatment as compared to WDR5 depletion. WDR5 depletion also sensitized colon cancer cells to radiation-induced DNA damage.ConclusionsThese data demonstrate a clear role for WDR5 in colon cancer and future studies should examine its potential to serve as a therapeutic target in cancer. Additional studies are needed to fully elucidate if the requirement for WDR5 is independent of or consistent with its role within the COMPASS complex. OICR-9429 treatment was particularly toxic to SW620 and T84 colon cancer cells, two cell lines without mutations in WDR5 and KMT2/MLL proteins suggesting COMPASS complex inhibition may be particularly effective in tumors lacking KMT2 mutations. Additionally, the ability of WDR5 depletion to amplify the toxic effects of radiation presents the possibility of targeting WDR5 to sensitize cells to DNA-damaging therapies.

Pharmacokinetics and efficacy of orally administered polymeric chloroquine as macromolecular drug in the treatment of inflammatory bowel disease

Inflammatory bowel disease is a chronic inflammation of the gastrointestinal tract with poor understanding of its pathogenesis and no effective cure. The goal of this study was to evaluate the feasibility of orally administered non-degradable polymeric chloroquine (pCQ) to locally reduce colon inflammation. The pCQ was synthesized by radical copolymerization of N-(2-hydroxypropyl)methacrylamide with methacryloylated hydroxychloroquine (HCQ). The anti-inflammatory activity of orally administered pCQ versus HCQ was tested in a mouse model of colitis induced by Citrobacter rodentium (C. rodentium). Single-dose pharmacokinetic and biodistribution studies performed in the colitis model indicated negligible systemic absorption (p ≤ 0.001) and localization of pCQ in the gastrointestinal tract. A multi-dose therapeutic study demonstrated that the localized pCQ treatment resulted in significant reduction in the colon inflammation (p ≤ 0.05). Enhanced suppression of pro-inflammatory cytokines IL-6 (p ≤ 0.01) and IL1-β and opposing upregulation of IL-2 (p ≤ 0.05) recently reported to be involved in downstream anti-inflammatory events suggested that the anti-inflammatory effects of the pCQ are mediated by altering mucosal immune homeostasis. Overall, the reported findings demonstrate a potential of pCQ as a novel polymer therapeutic option in inflammatory bowel disease with the potential of local effects and minimized systemic toxicity.

Re: The American Society of Peritoneal Surface Malignancies Multi-Institution Evaluation of 1,051 Advanced Ovarian Cancer Patients Undergoing Cytoreductive Surgery and HIPEC: An Introduction of the Peritoneal Surface Disease Severity Score. Journal of Surgical Oncology 2016;114(7):779–784.

1Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska 2Department of Gastrointestinal Surgery, Ghent University Hospital Belgium, Gent, Belgium 3National Cancer Institute of Milan, Milan, Italy 4Department of Gynecologic Oncology, Aegean Obstetrics and Gynecology Education and Research Hospital, Izmir, Turkey 5Department of Surgery, Wake Forest University Baptist Medical Center, Winston Salem, North Carolina 6Unit of Oncological and Pancreatic Surgery, Department of General and Digestive Surgery, University Hospital Reina Sofia, Cordoba, Spain 7 Service de Chirurgie Générale et Oncologique, Centre Hospitalier Lyon-Sud, Pierre-Bénite, France 8Department of Surgical Oncology, St. Agnes Hospital, Baltimore, Maryland