A mixed treatment comparison of toxicity of gemcitabine combined with different targeted drugs in the treatment of advanced or metastatic pancreatic cancer

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.

A Retrospective Look at Anti-EGFR Agents in Pancreatic Cancer Therapy

Background:

The introduction of Monoclonal Antibodies (mAbs) and small-molecule Tyrosine Kinase Inhibitors (TKIs) that target the Epidermal Growth Factor Receptor (EGFR), marks a huge step forward in the Pancreatic Cancer (PC) therapy. However, anti-EGFR therapy is found to be successful only in a fraction of patients. Although anti-EGFR agents have shown considerable clinical promise, a serious adverse event associated with anti- EGFR therapy has been challenging. At this juncture, there is still more to be done in the search for effective predictive markers with therapeutic applicability.

Methods:

A focused literature search was conducted to summarize the existing evidence on anti-EGFR agents in pancreatic cancer therapy.

Results:

This review discusses various anti-EGFR agents currently in use for PC therapy and potential adverse effects associated with it. Existing evidence on EGFR TKIs demonstrated better tolerant effects and outcomes with multiple toxic regimens. Anti-EGFR therapy in combination with chemotherapy is necessary to achieve the best clinical outcomes.

Conclusion:

Future prospective studies on the identification of additional biological agents and novel anti-EGFR agents are warranted.

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.

EIF5A regulates proliferation and chemoresistance in pancreatic cancer through the sHH signalling pathway

BACKGROUND

Pancreatic cancer (PC) has a very poor prognosis and comparatively short survival. Eukaryotic translation initiation factor 5A (EIF5A) promotes cancer metastasis. Here, we exploited the biological role of EIF5A in PC chemoresistance.

METHODS

Expression of EIF5A was analysed in PC cells and tissues by real-time PCR, Western blotting, immunohistochemistry and immunofluorescent. EIF5A expression was specifically suppressed by transfection, and subsequently the alterations of growth behaviour and resistance to anticancer treatment were tested in an orthotopic tumour model.

RESULTS

The results showed EIF5A was increased in human PC tissues and PC cells. We found EIF5A knockdown reduced the PC proliferation ability in vivo and in vitro. In addition, sonic hedgehog (sHH) signalling pathway may be a downstream of EIF5A in PC cells. Inhibition of EIF5A and sHH signalling pathway could suppress PC cells proliferation and tumour growth. Importantly, EIF5A played an important role in gemcitabine sensitivity for PC.

CONCLUSION

Taken together, our results revealed that EIF5A regulated the proliferation of PC through the sHH signalling pathway and decreased the Gem sensitivity in PC, which provided a novel therapeutic strategy for PC patients.