Safety and Clinical Response to Combined Immunotherapy with Autologous iNKT Cells and PD-1+CD8+ T Cells in Patients Failing First-line Chemotherapy in Stage IV Pancreatic Cancer.

Purpose: A phase I clinical trial was conducted to assess the safety and feasibility of invariant natural killer T (iNKT) cells combined with PD-1+CD8+ T cells in patients with advanced pancreatic cancer and failing the first-line chemotherapy. Patients and Methods: Fifteen eligible patients were enrolled, of whom 9 received at least three cycles of treatment each. In total, 59 courses were administered. Results: Fever was the most common adverse event, peaking at about 2-4 hours after cell infusion and reverting within 24 hours without treatment in all patients. Influenza-like reactions such as headache, myalgia, and arthralgia were also observed in 4, 4, and 3 of the patients, respectively. In addition, vomiting and dizziness were prevalent, while abdominal pain, chest pain, rash, and stuffy nose were rare adverse events, each reported in 1 patient. Side effects above grade 2 were not observed. Two patients achieved partial regression, while 1 patient experienced disease progression assessed 4 weeks after the third course. Three patients are still alive at the time of writing and have progression-free survival longer than 12 months. The overall survival time has been extended to over 12 months in 6 of the 9 patients. No constant changes of CD4+ T, B, and NK cells were recorded except for elevated CD8+ T cells after the first course. Conclusions: The combination of autologous iNKT cells and PD-1+CD8+ T cells was a safe therapeutic strategy against advanced pancreatic cancer. The patients exhibited a potentially promising prolonged survival time. Further study appears warranted to evaluate the efficacy of these combined cell infusions in pancreatic cancer. Trial registration: This trial was included in the clinical trial which was registered in ClinicalTrials.gov (ID:NCT03093688) on March 15, 2017. Significance: There is an unmet need for novel, more effective, and tolerable therapies for pancreatic cancer. Here we present a phase I clinical trial employing iNKT cells combined with PD-1+CD8+ T cells in 9 patients with advanced pancreatic cancer and failing the first-line chemotherapy. The combined immunotherapy was shown to be feasible in the enrolled patients with limited side effects and optimistic clinical responses, which could bring opportunity of therapeutic advancement.

Improving the ex vivo expansion of human tumor-reactive CD8 + T cells by targeting toll-like receptors.

Toll-like receptors (TLRs) are important pattern recognition receptor(s) known to mediate the sensing of invading pathogens and subsequent immune responses. In this study, we investigate whether TLRs could be explored for the preparation of human CD8+ T cell products used in adoptive cell therapy (ACT). Following characterization of TLRs expression on human CD8+ T cells, we screened TLR-specific agonists for their ability to act in concert with anti-CD3 to stimulate the proliferation of these cells and corroborated the observed co-stimulatory effect by transcriptional profiling analyses. Consequently, we developed an optimal formulation for human CD8+ T cell amplification by combining CD3/CD28 antibody, interleukin 7 (IL-7), interleukin 15 (IL-15), and three agonists respectively targeting TLR1/2, TLR2/6, and TLR5. This new formulation performed better in amplifying PD-1+CD8+ T cells, a potential repertoire of tumor-reactive CD8+ T cells, from tumor patients than the conventional formulation. Importantly, the expanded CD8+ T cells showed restored functionality and consequently a robust anti-tumor activity in an in vitro co-culturing system. Together, our study established the utility of TLR agonists in ex vivo expansion of tumor-targeting CD8+ T cells, thus providing a new avenue toward a more effective ACT.

Feasibility of iNKT cell and PD-1+CD8+ T cell-based immunotherapy in patients with lung adenocarcinoma: Preliminary results of a phase I/II clinical trial.

We performed a single-arm exploratory clinical trial that is ongoing and registered at ClinicalTrials.gov (NCT03093688). Patients were infused with autologous iNKT cells, PD-1 + CD8+ T cells, and dendritic cells every 3-5 weeks, which was considered 1 cycle. The primary endpoints were safety and objective tumor response. The preliminary results from the first three patients are reported here. The first patient received 16 cycles. Computed tomography (CT) examination revealed a stable disease (SD) response after 4 cycles and progressive disease (PD) response after 11 cycles. For the second patient that received 10 cycles, CT examination revealed an SD response after 4 cycles and a PD response after 9 cycles. For the third patient who was treated with 6 cycles, CT examination revealed an SD response after 4 cycles. The patients suffered from only grade 1-2 adverse events. iNKT cell and PD-1 + CD8+ T cell-based immunotherapy showed a manageable tolerability profile.

Prevalence of pediatric Kashin-Beck disease in Tibet.

INTRODUCTION: To estimate the prevalence of Kashin-Beck disease (KBD) among children in 2017 in Changdu of Tibet. METHODS: We adopted a four-step recruitment to include children aged 7-12 years from seven identified historically endemic counties in Changdu. Posterior-anterior radiographs of right hand and wrist were taken and were graded at four sites (metaphysis, epiphysis, and bony end of phalanges and metacarpal and carpal bones). Two trained researchers independently read the films. Inter-rater reliability was assessed using weighted Kappa and percentage agreement. We fitted logistic regression model to examine the association of age, sex, and altitude of residential village with prevalence of KBD. We examined association between site involvement and severity of KBD using chi-square test. RESULTS: We recruited 13,573 children (mean age = 9.3 years, 48.40% girls) with a response rate of 95.81%. The overall prevalence of radiographic KBD was 0.26%. Luolong County had the highest prevalence (0.69%), followed by Bianba (0.26%), Basu (0.24%), Mangkang (0.14%), Zuogong (0.14%), Dingqing (0.07%), and Chaya (0.00%). A higher risk of radiographic KBD was associated with older age (P for trend <0.001) and girls (OR=1.86, 95% CI: 0.94, 3.70), but not the altitude of residential village (P for trend=0.957). Metaphysis was involved in all cases of KBD while lesions in epiphysis and bony end of phalanges and metacarpals were only observed in severe cases. CONCLUSIONS: The prevalence of radiographic KBD among children aged 7-12 years was low in Changdu compared with previous census data, suggesting the effectiveness of preventative measures. Key Points • In this study, 13,573 Tibetan children were taken X-ray films of their hands and wrists. • The prevalence of radiographic KBD among children aged 7-12 years was low in Changdu of Tibet. • The preventative measures against KBD launched by Chinese government were effective in decreasing new onsets of KBD among Tibetan children.

Correlation Between Early Plasma Interleukin 37 Responses With Low Inflammatory Cytokine Levels and Benign Clinical Outcomes in Severe Acute Respiratory Syndrome Coronavirus 2 Infection.

BACKGROUND: The immune protective mechanisms during severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection remain to be deciphered for the development of an effective intervention approach. METHODS: We examined early responses of interleukin 37 (IL-37), a powerful anti-inflammatory cytokine, in 254 SARS-CoV-2-infected patients before any clinical intervention and determined its correlation with clinical prognosis. RESULTS: Our results demonstrated that SARS-CoV-2 infection causes elevation of plasma IL-37. Higher early IL-37 responses were correlated with earlier viral RNA negative conversion, chest computed tomographic improvement, and cough relief, consequently resulted in earlier hospital discharge. Further assays showed that higher IL-37 was associated with lower interleukin 6 and interleukin 8 (IL-8) and higher interferon α responses and facilitated biochemical homeostasis. Low IL-37 responses predicted severe clinical prognosis in combination with IL-8 and C-reactive protein. In addition, we observed that IL-37 administration was able to attenuate lung inflammation and alleviate respiratory tissue damage in human angiotensin-converting enzyme 2-transgenic mice infected with SARS-CoV-2. CONCLUSIONS: Overall, we found that IL-37 plays a protective role by antagonizing inflammatory responses while retaining type I interferon, thereby maintaining the functionalities of vital organs. IL-37, IL-8, and C-reactive protein might be formulated as a precise prediction model for screening severe clinical cases and have good value in clinical practice.

An open-label, randomized trial of the combination of IFN-κ plus TFF2 with standard care in the treatment of patients with moderate COVID-19.

BACKGROUND: Epidemic outbreaks caused by SARS-CoV-2 are worsening around the world, and there are no target drugs to treat COVID-19. IFN-κ inhibits the replication of SARS-CoV-2; and TFF2 is a small secreted polypeptide that promotes the repair of mucosal injury and reduces the inflammatory responses. We used the synergistic effect of both proteins to treat COVID-19. METHODS: We conducted an open-label, randomized, clinical trial involving patients with moderate COVID-19. Patients were assigned in a 1:1 ratio to receive either aerosol inhalation treatment with IFN-κ and TFF2 every 24 h for six consecutive dosages in addition to standard care (experimental group) or standard care alone (control group). The primary endpoint was the time until a viral RNA negative conversion for SARS-CoV-2 in all clinical samples. The secondary clinical endpoint was the time of CT imaging improvement. Data analysis was performed per protocol. This study was registered with chictr.org.cn, ChiCTR2000030262. FINDINGS: Between March 23 and May 23 of 2020, 86 COVID-19 patients with symptoms of moderate illness were recruited, and 6 patients were excluded due to not matching the inclusion criteria (patients with pneumonia through chest radiography). Among the remaining 80 patients, 40 patients were assigned to experimental group, and the others were assigned to control group to only receive standard care. Efficacy and safety were evaluated for both groups. The time of viral RNA negative conversion in experimental group (Mean, 3·80 days, 95% CI 2·07-5·53), was significantly shorter than that in control group (7·40 days, 95% CI 4·57 to 10·23) (p = 0.031), and difference between means was 3·60 days. The percentage of patients in experimental group with reversion to negative viral RNA was significantly increased compared with control group on all sampling days (every day during the 12-day observation period) (p = 0·037). For the secondary endpoint, the experimental group had a significantly shorter time until improvement was seen by CT (Mean 6·21 days, N = 38/40, 95% CI 5·11-7·31) than that in control group (8·76 days, N = 34/40, 95% CI 7·57-9·96) (p = 0.002), and difference between means was 2·55 days. No discomfort or complications during aerosol inhalation were reported to the nurses by any experimental patients. INTERPRETATION: In conclusion, we found that aerosol inhalation of IFN-κ plus TFF2 in combination with standard care is safe and superior to standard care alone in shortening the time up to viral RNA negative conversion in all clinical samples. In addition, the patients in experimental group had a significantly shortened CT imaging improvement time than those in control group. This study suggested that this combination treatment is able to facilitate clinical improvement (negative for virus, improvement by CT, reduced hospitalization stay) and thereby result in an early release from the hospital. These data support the need for exploration with a large-scale trial of IFN-κ plus TFF2 to treat COVID-19. FUNDING: Funding was provided by the National Natural Science Foundation of China, National Major Project for Control and Prevention of Infectious Disease in China, Shanghai Science and Technology Commission, Shanghai Municipal Health Commission.

Negative regulation between the expression levels of receptor for hyaluronic acid-mediated motility and hyaluronan leads to cell migration in pancreatic cancer.

Receptor for hyaluronic acid (HA)-mediated motility (RHAMM) expression is upregulated in pancreatic ductal adenocarcinoma (PDAC). In the present study, small interfering RNA knockdown was used to investigate the regulatory mechanism and function of RHAMM in PDAC cells. Reverse transcription-quantitative PCR was used to measure the mRNA expression levels of RHAMM, hyaluronan synthases (HAS1, HAS2 and HAS3) and hyaluronidases (HYAL1, HYAL2 and HYAL3) in eight PDAC cell lines. Cell migration was assessed using a Transwell assay, while HA concentration was measured using an ELISA. The results revealed that RHAMM-knockdown significantly increased migration in two PDAC cell lines, significantly decreased migration in one cell line and did not affect migration in the other cell lines, and was positively associated with changes in HA production. There was a linear negative correlation between RHAMM mRNA expression and HA concentration in PDAC cells and tissues. The negative correlation between RHAMM mRNA expression and HA concentration was demonstrated in other models, including SUIT2 cells treated with an HA inhibitor or stimulator and a system involving co-culture of SUIT2 cells and stromal fibroblasts. The present findings demonstrated a negative correlation between RHAMM mRNA expression and HA production in a subset of PDAC cell lines. The efficacy of a therapeutic strategy targeting RHAMM should be carefully evaluated in future studies.

A clinical pilot study on the safety and efficacy of aerosol inhalation treatment of IFN-κ plus TFF2 in patients with moderate COVID-19.

BACKGROUND: The outbreak of a new coronavirus (SARS-CoV-2) poses a great challenge to global public health. New and effective intervention strategies are urgently needed to combat the disease. METHODS: We conducted an open-label, non-randomized, clinical trial involving moderate COVID-19 patients according to study protocol. Patients were assigned in a 1:2 ratio to receive either aerosol inhalation treatment with IFN-κ and TFF2, every 48 h for three consecutive dosages, in addition to standard treatment (experimental group), or standard treatment alone (control group). The end point was the time to discharge from the hospital. This study is registered with chictr.org.cn, ChiCTR2000030262. FINDINGS: A total of thirty-three eligible COVID-19 patients were enrolled from February 1, 2020 to April 6, 2020, eleven were assigned to the IFN-κ plus TFF2 group, and twenty-two to the control group. Safety and efficacy were evaluated for both groups. No treatment-associated severe adverse effects (SAE) were observed in the group treated with aerosol inhalation of IFN-κ plus TFF2, and no significant differences in the safety evaluations were observed between experimental and control groups. CT imaging was performed in all patients with the median improvement time of 5.0 days (IQR 3.0-9.0) in the experimental group versus 8.5 days (IQR 3.0-17.0) in the control group (p<0.05). In addition, the experimental group had a significant shorten median time in cough relief (4.5 days [IQR 2.0-7.0]) than the control group did (10.0 days [IQR 6.0-21.0])(p<0.005), in viral RNA reversion of 6.0 days (IQR 2.0-13.0) in the experimental group vs 9.5 days (IQR 3.0-23.0) in the control group (p < 0.05), and in the median hospitalization stays of 12.0 days (IQR 7.0-20.0) in the experimental group vs 15.0 days (IQR 10.0-25.0) in the control group (p<0.001), respectively. INTERPRETATION: Aerosol inhalation of IFN-κ plus TFF2 is a safe treatment and is likely to significantly facilitate clinical improvement, including cough relief, CT imaging improvement, and viral RNA reversion, thereby achieves an early release from hospitalization. These data support to explore a scale-up trial with IFN-κ plus TFF2. FUNDING: National Major Project for Control and Prevention of Infectious Disease in China, Shanghai Science and Technology Commission, Shanghai Municipal Health Commission.

Pure nongestational uterine choriocarcinoma in postmenopausal women: a case report with literature review.

Nongestational choriocarcinoma is rare, especially in postmenopausal women. It may be derived from the transformation of germ cells or dedifferentiation of other tumor tissue cells. It is usually found in the ovaries but rarely in the uterus. Pure nongestational uterine choriocarcinoma in postmenopausal women is exceptional. Thirty-four cases of choriocarcinoma have been found during the past 25 y at the Tianjin Medical University General Hospital. We retrospectively reviewed the medical records of these 34 cases and found only two cases of nongestational uterine choriocarcinoma, both of which were postmenopausal women. We also reviewed 19 other cases previously reported during the past 50 y (from 1970 to 2018) that were identified as uterine choriocarcinoma in postmenopausal women. Analysis of these combined data indicates that nongestational choriocarcinoma is a rare neoplasm in postmenopausal patients. It genetically originates entirely in the patient, and short tandem repeat (STR) analyses are usually required to differentiate gestational and nongestational choriocarcinoma. Although nongestational choriocarcinoma shows some response to chemotherapy, sensitivity is much poorer than that in gestational choriocarcinoma. The prognosis for nongestational choriocarcinoma is poor and the long-term survival rate is low.

Enhanced Opsonization-Independent Phagocytosis and High Response Ability to Opsonized Antigen-Antibody Complexes: A New Role of Kupffer Cells in the Accelerated Blood Clearance Phenomenon upon Repeated Injection of PEGylated Emulsions.

The accelerated blood clearance (ABC) phenomenon is an immune response against the first injection of PEGylated colloidal drug delivery systems (CDDSs), which causes the accelerated clearance of the second dose. The enhanced complement-mediated phagocytic activity of Kupffer cells is responsible for accelerated second-dose clearance. Nevertheless, few studies have focused on the role of Kupffer cells in the induction phase of the ABC phenomenon. In this study, the intrinsic phagocytic activity of Kupffer cells was significantly enhanced at 6 days after the initial injected PEGylated emulsions (PEs) using the carbon clearance test and single-pass liver perfusion experiment. Furthermore, PE could stimulate Kupffer cells activation, leading to enhanced cell viability of Kupffer cells and opsonization-independent cellular uptake. It was also found that the response ability of Kupffer cells to the antigen-antibody complexes was augmented by the first injection of PE. Conclusively, we proposed that, besides anti-PEG IgM and complement activation-mediated hepatic uptake, enhanced opsonization-independent phagocytosis of Kupffer cells and the high response ability to opsonized antigen-antibody complexes contribute to the accelerated clearance of the second administration. The results indicated that Kupffer cells play an indispensable role in the ABC phenomenon and provided novel insights into the current view on the mechanism of the ABC effect.

4-Methylumbelliferone inhibits enhanced hyaluronan synthesis and cell migration in pancreatic cancer cells in response to tumor-stromal interactions.

Hyaluronic acid (HA) in tumor stroma promotes tumor invasion and progression. 4-Methylumbelliferone (4-MU) is a potent HA synthesis inhibitor. In the present study, the effects of 4-MU on enhanced HA synthesis and cell migration in pancreatic ductal adenocarcinoma (PDAC) cells, in response to co-culture with stromal fibroblasts, was investigated. The HA concentration was determined using ELISA and a Transwell migration assay was used to analyze cell migratory capability. The mRNA expression levels of hyaluronan synthases (HAS1, HAS2 and HAS3) were determined using the quantitative polymerase chain reaction. Co-culture between Panc-1 cells and stromal fibroblasts markedly increased cell migration in association with increasing HA production, which was markedly associated with an increase in HAS3 mRNA expression. Treatment with 4-MU markedly decreased the HA production and cell migration of Panc-1 cells in the co-culture system. The results of the present study suggested that interactions between PDAC cells and stromal fibroblasts increased HA production, resulting in a marked increase in migration of PDAC cells, and 4-MU may be used as a chemotherapeutic agent to inhibit the enhanced migration of PDAC cells in response to tumor-stromal interactions.

Neutrophil-mediated delivery of pixantrone-loaded liposomes decorated with poly(sialic acid)-octadecylamine conjugate for lung cancer treatment.

Poly(sialic acid) (PSA) is a natural hydrophilic biodegradable and non-immunogenic biopolymer, receptors for its monomer are expressed on peripheral blood neutrophils (PBNs), which plays important roles in the progression and invasion of tumors. A poly(sialic acid)-octadecylamine conjugate (PSA-ODA) was synthesized and then anchor it on the surface of liposomal pixantrone (Pix-PSL), to achieve an improved anticancer effect. The liposomes were prepared using a remote loading method via a pH gradient, and then assessed for particle size, zeta potential encapsulation efficiency, in vitro release, and in vitro cytotoxicity. Simultaneously, in vitro and in vivo cellular uptake studies confirmed that PSA-decorated liposomes provided an enhanced accumulation of liposomes in PBNs. An in vivo study presented that the anti-tumor activity of Pix-PSL was superior to that of other Pix formulations, probably due to the efficient targeting of PBNs by Pix-PSL, after which PBN containing Pix-PSL (Pix-PSL/PBNs) in the blood circulation are recruited by the tumor microenvironment. These findings suggest that PSA-decorated liposomal Pix may provide a neutrophil-mediated drug delivery system (DDS) for the eradication of tumors, which represents a promising approach for the tumor targeting of chemotherapeutic treatments.

KIAA1199/CEMIP/HYBID overexpression predicts poor prognosis in pancreatic ductal adenocarcinoma.

BACKGROUND: KIAA1199 (also known as CEMIP or HYBID), a newly identified protein involved in hyaluronan degradation, has been suggested to play a critical role in cancer progression. The aim of this study was to investigate the expression and functional significance of KIAA1199 in pancreatic ductal adenocarcinoma (PDAC). METHODS: Using quantitative real-time RT-PCR, we analyzed KIAA1199 mRNA expression in 6 PDAC cell lines and frozen tissues from 14 patients with PDAC. We also used immunohistochemistry to analyze KIAA1199 protein expression in formalin-fixed, paraffin-embedded tissues from 98 patients with PDAC. The KIAA1199 expression pattern was then correlated with clinicopathological variables and patient outcome. The effect of KIAA1199 on migratory ability of PDAC cells was determined by KIAA1199 knockdown with small-interfering RNA (siRNA). RESULTS: The KIAA1199 mRNA expression was significantly higher in PDAC tissues than in the corresponding non-tumor tissues (P < 0.0001). Immunohistochemical analysis revealed high expression of KIAA1199 in 26 (26.5%) of 98 PDAC tissues. The overall survival was significantly shorter in patients with high KIAA1199 expression than in patients with low KIAA1199 expression (P = 0.0001). In multivariate analysis, high KIAA1199 expression (P = 0.003) and UICC stage (P = 0.003) were independent factors predicting poor prognosis. Furthermore, the KIAA1199 mRNA expression was higher in most PDAC cell lines and siRNA knockdown of KIAA1199 resulted in decreased migration. CONCLUSION: These findings suggest that overexpression of KIAA1199 may contribute to increased migration of PDAC cells and predict shorter survival after surgical resection.

Increased Expression of HYAL1 in Pancreatic Ductal Adenocarcinoma.

OBJECTIVES: Increased production and processing (degradation) of hyaluronan (HA) is critical for cancer invasion and metastasis. Although HA is known to be overexpressed in pancreatic ductal adenocarcinoma (PDAC), little is known about the expression and biological significance of HA-degrading enzymes, hyaluronidases (HYALs), in PDAC. METHODS: Expression of HYALs mRNA was examined in PDAC cells by quantitative real-time RT-PCR. HYAL1 protein expression was examined in primary PDAC tumors by enzyme-linked immuno-sorbent assay. The migratory ability of PDAC cells was determined by a transwell cell migration assay. RESULTS: Screening of mRNA expression of three major HYAL genes (HYAL1, 2, and 3) identified HYAL1 as a gene overexpressed in PDAC cells. Treatment of PDAC cells with 5-aza-2'-deoxycytidine and/or trichostatin A further increased the HYAL1 expression, suggesting a possible involvement of epigenetic mechanisms in the transcriptional regulation of this gene. HYAL1 protein concentrations were significantly higher in primary PDAC tissues as compared with nontumor pancreatic tissues (P = 0.049). Importantly, inhibition of HYAL activity by dextran sulfate significantly inhibited the migration of PDAC cells showing strong HYAL1 expression (P = 0.002). CONCLUSIONS: These findings suggest that overexpression of HYAL1 is a common mechanism that may contribute to the aggressive phenotype of PDAC.

The 12-3-12 cationic gemini surfactant as a novel gastrointestinal bioadhesive material for improving the oral bioavailability of coenzyme Q10 naked nanocrystals.

To improve the oral bioavailability of nanocrystalline drug preparations, the cationic 12-3-12 quaternary ammonium surfactant gemini was introduced into nanocrystals as a novel gastrointestinal bioadhesive material. Coenzyme Q10 (CoQ10), a typical Biopharmaceutics Classification System (BCS) class II drug, was used as a model drug. The 12-3-12 gemini surfactant was added to the preparation at a low concentration and imbued the particles with abundant positive charges. In vitro and in vivo gastrointestinal adhesion tests confirmed that the gemini-modified nanocrystals were prone to adhere to the upper gastrointestinal tract (GIT), thereby prolonging retention time in the GIT and enhancing absorption. In the distribution study in rats, the use of nanocrystals modified with gemini led to greater drug distribution to the heart and the liver than that achieved with the naked nanocrystals. A pharmacokinetic study in beagle dogs showed that the gemini-modified CoQ10 nanocrystals improved the oral bioavailability of CoQ10 in a dose-dependent manner, and the smaller size produced a much better effect with the same gemini modification. These results demonstrate that the cationic surfactant gemini is a promising oral bioadhesive material with applications in nanoscale drug delivery systems.

Targeting hyaluronan for the treatment of pancreatic ductal adenocarcinoma.

Progression of cancer is often associated with interactions between cancer cells and extracellular matrix (ECM) surrounding them. Increasing evidence has suggested that accumulation of hyaluronan (HA), a major component of ECM, provides a favorable microenvironment for cancer progression. Pancreatic ductal adenocarcinoma (PDAC) is characterized typically by a dense desmoplastic stroma with a large amount of HA, making this molecule as an attractive target for therapy. Several studies have shown efficacy of inhibitors of HA synthesis or signaling for the treatment of PDAC. Recent studies have also demonstrated substantial improvements in the effects of chemotherapy by a targeted depletion of stromal HA in PDAC using an enzymatic agent. Thus, targeting HA has been recognized as a promising therapeutic strategy to treat this highly aggressive neoplasm. In this review article, we summarize our current understanding of the role of HA in the progression of PDAC and discuss possible therapeutic approaches targeting HA.

A novel epigenetic mechanism regulating hyaluronan production in pancreatic cancer cells.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by an abundant stroma enriched with hyaluronan (HA), a major component of extracellular matrix known to play a critical role in tumor progression. The mechanisms that regulate HA synthesis in PDAC are poorly understood. To investigate whether DNA methylation and HA production from PDAC cells are associated, we studied the effect of 5-aza-2'-deoxycitidine (5-aza-dC), an inhibitor of DNA methylation, or DNA methyltransferase 1 (DNMT1) knockdown by small interfering RNA, on the HA production from PDAC cells. HA production into the conditioned medium was evaluated in PDAC cells treated with 5-aza-dC or DNMT1 knockdown. mRNA expression of HA synthase (HAS) genes was investigated by real-time RT-PCR. Treatment of PDAC cells with 5-aza-dC led to a significant increase in the HA production (up to 2.5-fold increase) in all 4 cell lines tested. This enhanced HA production by 5-aza-dC treatment was accompanied by increased mRNA expression of HAS2 and HAS3. Furthermore, increased HA production and HAS2/HAS3 mRNA expression was also observed in PDAC cells by knockdown of DNMT1. These findings provide evidence, for the first time, that epigenetic mechanism is involved in the regulation of HA synthesis in PDAC cells.

Hyaluronan stimulates pancreatic cancer cell motility.

Hyaluronan (HA) accumulates in pancreatic ductal adenocarcinoma (PDAC), but functional significance of HA in the aggressive phenotype remains unknown. We used different models to investigate the effect of HA on PDAC cell motility by wound healing and transwell migration assay. Changes in cell motility were examined in 8 PDAC cell lines in response to inhibition of HA production by treatment with 4-methylumbelliferone (4-MU) and to promotion by treatment with 12-O-tetradecanoyl-phorbol-13-acetate (TPA) or by co-culture with tumor-derived stromal fibroblasts. We also investigated changes in cell motility by adding exogenous HA. Additionally, mRNA expressions of hyaluronan synthases and hyaluronidases were examined using real time RT-PCR. Inhibition of HA by 4-MU significantly decreased the migration, whereas promotion of HA by TPA or co-culture with tumor-derived fibroblasts significantly increased the migration of PDAC cells. The changes in HA production by these treatments tended to be associated with changes in HAS3 mRNA expression. Furthermore, addition of exogenous HA, especially low-molecular-weight HA, significantly increased the migration of PDAC cells. These findings suggest that HA stimulates PDAC cell migration and thus represents an ideal therapeutic target to prevent invasion and metastasis.

Receptor for Hyaluronic Acid-Mediated Motility is Associated with Poor Survival in Pancreatic Ductal Adenocarcinoma.

Receptor for hyaluronic acid (HA)-mediated motility (RHAMM) is a nonintegral cell surface receptor involved in the aggressive phenotype in a wide spectrum of human malignancies, but the significance of RHAMM in pancreatic ductal adenocarcinoma (PDAC) remains unknown. In this study, we investigated the expression of RHAMM and its clinical relevance in PDAC. RHAMM mRNA expression was examined in 8 PDAC cell lines and in primary pancreatic cancer and adjacent non-tumor tissues from 14 patients using real-time RT-PCR. Western blotting was carried out to analyze the expression of RHAMM protein in PDAC cell lines. We also investigated the expression patterns of RHAMM protein in tissue samples from 70 PDAC patients using immunohistochemistry. The RHAMM mRNA expression was increased in some PDAC cell lines as compared to a non-tumorous pancreatic epithelial cell line HPDE. The RHAMM mRNA expression was significantly higher in PDAC tissues as compared to corresponding non-tumorous pancreatic tissues (P < 0.0001). The RHAMM protein expression was higher in the vast majority of PDAC cell lines relative to the expression in HPDE. The immunohistochemical analysis revealed strong expression of RHAMM in 52 (74%) PDAC tissues. Strong expression of RHAMM was significantly associated with a shorter survival time (P = 0.038). In multivariate analysis, tumor stage (P = 0.039), residual tumor (P = 0.015), and strong RHAMM expression (P = 0.034) were independent factors predicting poor survival. Strong expression of RHAMM may predict poor survival in PDAC patients and may provide prognostic and, possibly, therapeutic value.

Accelerated blood clearance phenomenon upon cross-administration of PEGylated nanocarriers in beagle dogs.

The cross-administration of nanocarriers modified by poly(ethylene glycol) (PEG), named PEGylated nanocarriers, a type of combination therapy, is becoming an increasingly important method of long-term drug delivery, to decrease side effects, avoid multidrug resistance, and increase therapeutic efficacy. However, repeated injections of PEGylated nanocarriers induces the accelerated blood clearance (ABC) phenomenon, prevents long circulation, and can cause adverse effects owing to alterations in the biodistribution of the drug. Although the nature of the ABC phenomenon that is induced by repeated injections of PEGylated nanocarriers has already been studied in detail, there are few reports on the immune response elicited by the cross-administration of PEGylated nanocarriers. In this study, we investigated the ABC phenomenon induced by the intravenous cross-administration of various PEGylated nanocarriers, including PEGylated liposomes (PL), PEG micelles (PM), PEGylated solid lipid nanoparticles (PSLN), and PEGylated emulsions (PE), in beagle dogs. The results indicated that the magnitude of the immune response elicited by the cross-administration was in the following order (from the strongest to the weakest): PL, PE, PSLN, PM. It is specifically PEG in the brush structure that elicits a significant immune response, in both the induction phase and the effectuation phase. Furthermore, the present study suggests that there is a considerable difference between the effect of repeated injections and cross-administration, depending on the colloidal structure. This work is a preliminary investigation into the cross-administration of PEGylated nanocarriers, and our observations can have serious implications for the design of combination therapies that use PEGylated vectors.