Bisphosphonates inhibit stellate cell activity and enhance antitumor effects of nanoparticle albumin-bound paclitaxel in pancreatic ductal adenocarcinoma

The role of vitamin C in the prevention of pancreatic cancer: a systematic-review

Introduction and aim

The aim of this systematic review was to assess the role of vitamin C in the prevention of pancreatic cancer (PC).

Methods

A comprehensive literature search was performed in PubMed, Embase and Web of Science up to August 2023, to identify randomized controlled trials (RCT), cohort studies and mendelian randomization studies based on prospective databases assessing the role of vitamin C in PC prevention.

Results

A total of twelve studies including European and North-American participants were included: two RCT, three mendelian randomization (MR) studies and seven cohort studies. Both RCT showed high quality in Cochrane risk of bias tool. Only one cohort study had <7 points in Newcastle Ottawa Scale. Both RCT found no association between the intake of 500 mg/day of vitamin C and the incidence of PC. Only one prospective cohort study found an association between vitamin C serum levels and a lower incidence of PC. The remaining cohort studies and MR studies found no association between dietary/supplements intake of vitamin C or circulating vitamin C levels and the incidence of PC.

Conclusion

There is no supporting evidence that vitamin C prevents PC development. Future prospective quality studies including high-risk populations are needed.

Sequentially Released Liposomes Enhance Anti-Liver Cancer Efficacy of Tetrandrine and Celastrol-Loaded Coix Seed Oil

Background

A sequential release co-delivery system is an effective strategy to improve anti-cancer efficacy. Herein, multicomponent-based liposomes (TET-CTM/L) loaded with tetrandrine (TET) and celastrol (CEL)-loaded coix seed oil microemulsion (CTM) were fabricated, which showed synergistic anti-liver cancer activities. By virtue of Enhanced Permeability and Retention (EPR) effect, TET-CTM/L can achieve efficient accumulation at the tumor site. TET was released initially to repair abnormal vessels and decrease the fibroblasts, and CTM was released subsequently for eradication of tumor tissue.

Methods

TEM (transmission electron microscopy) and DLS (dynamic light scattering) were adopted to characterize the TET-CTM/L. Flow cytometry was adopted to examine the cellular uptake and cytotoxicity of HepG2 cells. The HepG2 xenograft nude mice were adopted to evaluate the anti-tumor efficacy and systemic safety of TET-CTM/L.

Results

TEM images of TET-CTM/L showed the structure of small particle size of CTM within large-size liposomes, indicating that CTM can be encapsulated in liposomes by film dispersion method. In in vitro studies, TET-CTM/L induced massive apoptosis toward HepG2 cells, indicating synergistic cytotoxicity against HepG2 cells. In in vivo studies, TET-CTM/L displayed diminished systemic toxicity compared to celastrol or TET used alone. TET-CTM/L showed the excellent potential for tumor-targeting ability in a biodistribution study.

Conclusion

Our study provides a new strategy for combining anti-cancer therapy that has good potential not only in the treatment of liver cancer but also can be applied to the treatment of other solid tumors.

Zoledronic Acid Abrogates Restraint Stress-Induced Macrophage Infiltration, PDGF-AA Expression, and Ovarian Cancer Growth

Simple Summary

Biobehavioral disorders can negatively impact patients with ovarian cancer. Growing evidence suggests that chronic stress can promote tumor progression, the release of inflammatory mediators, and macrophage infiltration into the tumor. However, the role of stress hormones in regulating cancer cell/macrophage crosstalk remains unclear. This study aimed to assess the role of stress hormone-stimulated macrophages in modulating inflammatory networks and ovarian cancer biology. Our data show that stress hormones induced secretion of inflammatory proteins in ovarian cancer cell/macrophage co-cultures. Furthermore, we show that restraint stress leads to cancer growth, macrophage infiltration, and PDGF-AA protein expression in animal models of ovarian cancer. Conversely, zoledronic acid was able to prevent the effects of restraint stress on ovarian cancer growth. Overall, our data suggest a role for stress hormone-stimulated macrophages in ovarian cancer progression and suggest the involvement of PDGF-AA as a key mediator of this process.

Abstract

Multiple studies suggest that chronic stress accelerates the growth of existing tumors by activating the sympathetic nervous system. Data suggest that sustained adrenergic signaling can induce tumor growth, secretion of pro-inflammatory cytokines, and macrophage infiltration. Our goal was to study the role of adrenergic-stimulated macrophages in ovarian cancer biology. Cytokine arrays were used to assess the effect of adrenergic stimulation in pro-tumoral cytokine networks. An orthotopic model of ovarian cancer was used to assess the in vivo effect of daily restraint stress on tumor growth and adrenergic-induced macrophages. Cytokine analyses showed that adrenergic stimulation modulated pro-inflammatory cytokine secretion in a SKOV3ip1 ovarian cancer cell/U937 macrophage co-culture system. Among these, platelet-derived growth factor AA (PDGF-AA), epithelial cell-derived neutrophil-activating peptide (ENA-78), Angiogenin, vascular endothelial growth factor (VEGF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-5 (IL-5), Lipocalin-2, macrophage migration inhibitory factor (MIF), and transferrin receptor (TfR) were upregulated. Enriched biological processes included cytokine-mediated signaling pathways and positive regulation of cell proliferation. In addition, daily restraint stress increased ovarian cancer growth, infiltration of CD68+ macrophages, and expression of PDGF-AA in orthotopic models of ovarian cancer (SKOV3ip1 and HeyT30), while zoledronic acid, a macrophage-depleting agent, abrogated this effect. Furthermore, in ovarian cancer patients, high PDGFA expression correlated with worse outcomes. Here, it is shown that the adrenergic regulation of macrophages and PDGFA might play a role in ovarian cancer progression.

Nanotechnology for angiogenesis: opportunities and challenges

Angiogenesis plays a critical role within the human body, from the early stages of life (i.e., embryonic development) to life-threatening diseases (e.g., cancer, heart attack, stroke, wound healing). Many pharmaceutical companies have expended huge efforts on both stimulation and inhibition of angiogenesis. During the last decade, the nanotechnology revolution has made a great impact in medicine, and regulatory approvals are starting to be achieved for nanomedicines to treat a wide range of diseases. Angiogenesis therapies involve the inhibition of angiogenesis in oncology and ophthalmology, and stimulation of angiogenesis in wound healing and tissue engineering. This review aims to summarize nanotechnology-based strategies that have been explored in the broad area of angiogenesis. Lipid-based, carbon-based and polymeric nanoparticles, and a wide range of inorganic and metallic nanoparticles are covered in detail. Theranostic and imaging approaches can be facilitated by nanoparticles. Many preparations have been reported to have a bimodal effect where they stimulate angiogenesis at low dose and inhibit it at higher doses.

Stellate Cells in the Tumor Microenvironment

As tumor microenvironments share many of the same qualities as chronic wounds, attention is turning to the wound-repair cells that support the growth of cancerous cells. Stellate cells are star-shaped cells that were first discovered in the perisinusoidal spaces in the liver and have been found to support wound healing by the secretion of growth factors and extracellular matrix. They have since been also found to serve a similar function in the pancreas. In both organs, the wound-healing process may become dysregulated and lead to pathological fibrosis (also known as cirrhosis in the liver). In recent years there has been increasing attention paid to the role of these cells in tumor formation and progression. They may be a factor in initiating the first steps of carcinogenesis such as with liver cirrhosis and hepatocellular carcinoma and also contribute to continued tumor growth, invasion, metastasis, evasion of the immune system, and resistance to chemotherapy, in cancers of both the liver and pancreas. In this chapter we aim to review the structure and function of hepatic and pancreatic stellate cells and their contributions to the tumor microenvironment in their respective cancers and also discuss potential new targets for cancer therapy based on our new understanding of these vital components of the tumor stroma.

Pancreatic stellate cells: Aiding and abetting pancreatic cancer progression

Tumour-stromal interactions have now been acknowledged to play a major role in pancreatic cancer (PC) progression. The abundant collagenous stroma is produced by a specific cell type in the pancreas-the pancreatic stellate cell (PSC). Pancreatic stellate cells (PSCs) are a unique resident cell type of pancreas and with a critical role in both healthy and diseased pancreas. Accumulating evidence indicates that PSCs interact closely with cancer cells as well as with other cell types of the stroma such as immune cells, endothelial cells and neuronal cells, to set up a growth permissive microenvironment for pancreatic tumours, which facilitates local tumour growth as well as distant metastasis. Consequently, recent work in the field has focused on the development of novel therapeutic approaches targeting the stroma to inhibit PC progression. Such a multi-pronged approach targeting both tumour and stromal elements of PC has been successfully applied in pre-clinical settings. The challenge now is to translate the pre-clinical findings into the clinical setting to achieve better outcomes for pancreatic cancer patients.

Pancreatic Stellate Cells: The Key Orchestrator of The Pancreatic Tumor Microenvironment

Pancreatic cancer is one of the most challenging adenocarcinomas due to its hostile molecular behavior and complex tumor microenvironment. It has been recently postulated that pancreatic stellate cells (PSCs), the resident lipid-storing cells of the pancreas, are important components of the tumor microenvironment as they can transdifferentiate into highly proliferative myofibroblasts in the context of tissue injury. Targeting tumor-stromal crosstalk in the tumor microenvironment has emerged as a promising therapeutic strategy against pancreatic cancer progression and metastasis. This chapter brings a broad view on the biological and pathological role of PSCs in the pancreas, activated stellate cells in the onset of tissue fibrosis, and tumor progression with particular emphasis on the bidirectional interactions between tumor cells and PSCs. Further, potential therapeutic regimens targeting activated PSCs in the pre-clinical and clinical trials are discussed.

Bisphosphonates Zometa and Fosamax Synergize with Metformin to Prevent AOM-Induced Colon Cancer in F344 Rat Model

Recent observational studies suggest that bisphosphonates (BP) and antidiabetic drugs are associated with colorectal cancer risk reduction. Hence, we evaluated the colorectal cancer preventive effects of BPs (zometa and fosamax), individually and when combined with metformin, in azoxymethane-induced rat colon cancer model. Rat (30/group) were randomized and treated subcutaneously with azoxymethane to induce colorectal cancer. Dietary intervention with zometa or fosamax (0, 20, or 100 ppm) or metformin (1,000 ppm) or the combinations (zometa/fosamax 20 ppm plus metformin 1,000 ppm) began 4 weeks after azoxymethane treatment, at premalignant lesions stage. Rats were killed 40 weeks post drug intervention to assess colorectal cancer preventive efficacy. Dietary zometa (20 ppm) inhibited noninvasive adenocarcinomas multiplicity by 37% (P < 0.03) when compared with control diet fed group. Fosamax at 20 ppm and 100 ppm significantly reduced adenocarcinoma incidence (P < 0.005) and inhibited the noninvasive adenocarcinoma multiplicities by 43.8% (P < 0.009) and 60.8% (P < 0.004), respectively, compared with the group fed control diet. At 1,000 ppm dose, metformin failed to suppress colon adenocarcinoma formation. However, the lower dose combinations of zometa or fosamax with metformin resulted in significant inhibition of noninvasive adenocarcinoma by 48% (P < 0.006) and 64% (P < 0.0002), and invasive adenocarcinoma by 49% (P < 0.0005) and 38% (P < 0.006), respectively. Biomarker analysis of combination drug-treated tumors showed a decrease in cell proliferation with increased apoptosis when compared with untreated tumors. Overall, our results suggest that the combination of low doses of zometa or fosamax with metformin showed synergistic effect and significantly inhibited colon adenocarcinoma incidence and multiplicity.

Bone metastasis as primary presentation of pancreatic ductal adenocarcinoma: A case report and literature review

PDAC bone metastases represent a clinical challenge characterized by multifaceted biological entity.

Angiogenesis in Pancreatic Cancer: Pre-Clinical and Clinical Studies

Angiogenesis is a crucial event in tumor development and progression, occurring by different mechanisms and it is driven by pro- and anti-angiogenic molecules. Pancreatic cancer vascularization is characterized by a high microvascular density, impaired microvessel integrity and poor perfused vessels with heterogeneous distribution. In this review article, after a brief introduction on pancreatic cancer classification and on angiogenesis mechanisms involved in its progression, the pre-clinical and clinical trials conducted in pancreatic cancer treatment using anti-angiogenic inhibitors will be described. Finally, we will discuss the anti-angiogenic therapy paradox between the advantage to abolish vessel supply to block tumor growth and the disadvantage due to reduction of drug delivery at the same time. The purpose is to identify new anti-angiogenic molecules that may enhance treatment regimen.

MSC-Delivered Soluble TRAIL and Paclitaxel as Novel Combinatory Treatment for Pancreatic Adenocarcinoma

Pancreatic cancer is the fourth leading cause of cancer death in western countries with more than 100,000 new cases per year in Europe and a mortality rate higher than 90%. In this scenario, advanced therapies based on gene therapies are emerging, thanks to a better understanding of tumour architecture and cancer cell alterations. We have demonstrated the efficacy of an innovative approach for pancreatic cancer based on mesenchymal stromal cells (MSC) genetically engineered to produce TNF-related Apoptosis Inducing Ligand (TRAIL). Here we investigated the combination of this MSC-based approach with the administration of a paclitaxel (PTX)-based chemotherapy to improve the potential of the treatment, also accounting for a possible resistance onset.

Methods: Starting from the BXPC3 cell line, we generated and profiled a TRAIL-resistant model of pancreatic cancer, testing the impact of the combined treatment in vitro with specific cytotoxicity and metabolic assays. We then challenged the rationale in a subcutaneous mouse model of pancreatic cancer, assessing its effect on tumour size accounting stromal and parenchymal organization.

Results: PTX was able to restore pancreatic cancer sensitivity to MSC-delivered TRAIL by reverting its pro-survival gene expression profile. The two compounds cooperate both in vitro and in vivo and the combined treatment resulted in an improved cytotoxicity on tumour cells.

Conclusion: In summary, this study uncovers the potential of a combinatory approach between MSC-delivered TRAIL and PTX, supporting the combination of cell-based products and conventional chemotherapeutics as a tool to improve the efficacy of the treatments, also addressing possible mechanisms of resistance.

The Modulatory Role of MicroRNA-873 in the Progression of KRAS-Driven Cancers

KRAS is one of the most frequently mutated proto-oncogenes in pancreatic ductal adenocarcinoma (PDAC) and aberrantly activated in triple-negative breast cancer (TNBC). A profound role of microRNAs (miRNAs) in the pathogenesis of human cancer is being uncovered, including in cancer therapy. Using in silico prediction algorithms, we identified miR-873 as a potential regulator of KRAS, and we investigated its role in PDAC and TNBC. We found that reduced miR-873 expression is associated with shorter patient survival in both cancers. miR-873 expression is significantly repressed in PDAC and TNBC cell lines and inversely correlated with KRAS levels. We demonstrate that miR-873 directly bound to the 3′ UTR of KRAS mRNA and suppressed its expression. Notably, restoring miR-873 expression induced apoptosis; recapitulated the effects of KRAS inhibition on cell proliferation, colony formation, and invasion; and suppressed the activity of ERK and PI3K/AKT, while overexpression of KRAS rescued the effects mediated by miR-873. Moreover, in vivo delivery of miR-873 nanoparticles inhibited KRAS expression and tumor growth in PDAC and TNBC tumor models. In conclusion, we provide the first evidence that miR-873 acts as a tumor suppressor by targeting KRAS and that miR-873-based gene therapy may be a therapeutic strategy in PDAC and TNBC.

Nano albumin bound-paclitaxel in pancreatic cancer: Current evidences and future directions

Pancreatic cancer (PDAC) is an aggressive and chemoresistant disease, representing the fourth cause of cancer related deaths in western countries. Majority of patients have unresectable, locally advanced or metastatic disease at time of diagnosis and the 5-year survival rate in these conditions is extremely low. For more than a decade gemcitabine has been the cornerstone of metastatic PDAC treatment, although survival benefit was very poor. PDAC cells are surrounded by an intense desmoplastic reaction that may create a barrier to the drugs penetration within the tumor. Recently PDAC stroma has been addressed as a potential therapeutic target. Nano albumin bound (Nab)-paclitaxel is an innovative molecule depleting tumor stroma, through interaction between albumin and secreted protein acidic and rich in cysteine. Addition of nab-paclitaxel to gemcitabine has showed activity and efficacy in metastatic PDAC first-line treatment improving survival and overall response rate vs gemcitabine alone in the MPACT phase III study. This combination represents one of the standards of care in advanced PDAC therapy and is suitable to a broader spectrum of patients compared to other schedules. Nab-paclitaxel is under investigation as a backbone of chemotherapy in novel combinations with target agents or immunotherapy in locally advanced or metastatic PDAC. In this article, we provide an updated and critical overview about the role of nab-paclitaxel in PDAC treatment based on the latest advances in preclinical and clinical research. Furthermore, we focus on the use of nab-paclitaxel within the context of metastatic PDAC treatment landscape and we discuss about future implications in the light of current clinical ongoing trials.

Exosomal miR-940 maintains SRC-mediated oncogenic activity in cancer cells: a possible role for exosomal disposal of tumor suppressor miRNAs

Exosomes have emerged as important mediators of diverse biological functions including tumor suppression, tumor progression, invasion, immune escape and cell-to-cell communication, through the release of molecules such as mRNAs, miRNAs, and proteins. Here, we identified differentially expressed exosomal miRNAs between normal epithelial ovarian cell line and both resistant and sensitive ovarian cancer (OC) cell lines. We found miR-940 as abundant in exosomes from SKOV3-IP1, HeyA8, and HeyA8-MDR cells. The high expression of miR-940 is associated with better survival in patients with ovarian serous cystadenocarcinoma. Ectopic expression of miR-940 inhibited proliferation, colony formation, invasion, and migration and triggered G0/G1 cell cycle arrest and apoptosis in OC cells. Overexpression of miR-940 also inhibited tumor cell growth in vivo. We showed that proto-oncogene tyrosine-protein kinase (SRC) is directly targeted by miR-940 and that miR-940 inhibited SRC expression at mRNA and protein levels. Following this inhibition, the expression of proteins downstream of SRC, such as FAK, paxillin and Akt was also reduced. Collectively, our results suggest that OC cells secrete the tumor-suppressive miR-940 into the extracellular environment via exosomes, to maintain their invasiveness and tumorigenic phenotype.

Targeting pancreatic cancer using a combination of gemcitabine with the omega-3 polyunsaturated fatty acid emulsion, Lipidem™

SCOPE

Pancreatic cancer remains a disease of poor prognosis, with alternate strategies being sought to improve therapeutic efficacy. Omega-3 fatty acids have shown clinical benefit, and mechanisms of action are under investigation.

METHODS AND RESULTS

Proliferation assays, flow cytometry, invasion assays, ELISA and western blotting were used to investigate efficacy of omega-3 fatty acids alone and in combination with gemcitabine. The docosahexanoic acid (DHA)/eicosapentanoic acid (EPA) combination, Lipidem™, in combination with gemcitabine inhibited growth in pancreatic cancer and pancreatic stellate cell (PSC) lines, with PSCs exhibiting greatest sensitivity to this combination. Invasion of pancreatic cancer cells and PSCs in a 3D spheroid model, was inhibited by combination of gemcitabine with Lipidem™. PSCs were required for cancer cell invasion in an organotypic co-culture model, with invasive capacity reduced by Lipidem™ alone. Platelet-derived growth factor (PDGF) is a key cytokine in pro-proliferative and invasion signalling, and thus a critical regulator of interactions between pancreatic cancer cells and adjacent stroma. Platelet-derived growth factor (PDGF-BB) secretion was completely inhibited by the combination of Lipidem™ with gemcitabine in cancer cells and PSCs.

CONCLUSION

Lipidem™ in combination with gemcitabine, has anti-proliferative and anti-invasive efficacy in vitro, with pancreatic stellate cells exhibiting the greatest sensitivity to this combination.

Pancreatic stellate cells: A dynamic player of the intercellular communication in pancreatic cancer

There is accumulating evidence that activated pancreatic stellate cells (PSCs) play a pivotal role in the development of pancreatic fibrosis within the pancreatic cancer tissue. Not only do they produce extracellular matrix components, PSCs dynamically interact with other cell types to constitute the cancer-conditioned microenvironment. There exist bidirectional interactions between PSCs and pancreatic cancer cells. Pancreatic cancer cells promote the proliferation, migration, extracellular matrix production and degradation, and angiogenetic responses in PSCs. In turn, PSCs promote the proliferation and migration, and inhibit the apoptosis of pancreatic cancer cells. PSCs also induce epithelial-mesenchymal transition and stem cell like phenotypes in pancreatic cancer cells, resulting in resistance to conventional therapies, distant metastasis, and recurrence. PSCs interact with endothelial cells, neural cells and β-cells, leading to angiogenesis, neurogenesis and β-cell dysfunction and apoptosis. PSCs cause impaired immune responses and help pancreatic cancer cells escape from host immune-surveillance. PSCs induce the differentiation of myeloid-derived suppressor cells, induce the apoptosis of T cells, inhibit the infiltration of T cells, and induce the activation of mast cells. Overall, these interactions appear to promote the progression of pancreatic cancer, and anti-stroma therapies targeting PSCs are under intense investigation. Further elucidation of these interactions could lead to the identification of novel therapeutic targets in pancreatic cancer.

Rac1/Pak1/p38/MMP-2 Axis Regulates Angiogenesis in Ovarian Cancer

PURPOSE

Zoledronic acid is being increasingly recognized for its antitumor properties, but the underlying functions are not well understood. In this study, we hypothesized that zoledronic acid inhibits ovarian cancer angiogenesis preventing Rac1 activation.

EXPERIMENTAL DESIGN

The biologic effects of zoledronic acid were examined using a series of in vitro [cell invasion, cytokine production, Rac1 activation, reverse-phase protein array, and in vivo (orthotopic mouse models)] experiments.

RESULTS

There was significant inhibition of ovarian cancer (HeyA8-MDR and OVCAR-5) cell invasion as well as reduced production of proangiogenic cytokines in response to zoledronic acid treatment. Furthermore, zoledronic acid inactivated Rac1 and decreased the levels of Pak1/p38/matrix metalloproteinase-2 in ovarian cancer cells. In vivo, zoledronic acid reduced tumor growth, angiogenesis, and cell proliferation and inactivated Rac1 in both HeyA8-MDR and OVCAR-5 models. These in vivo antitumor effects were enhanced in both models when zoledronic acid was combined with nab-paclitaxel.

CONCLUSIONS

Zoledronic acid has robust antitumor and antiangiogenic activity and merits further clinical development as ovarian cancer treatment.