Nanomedicine to Overcome Multidrug Resistance Mechanisms in Colon and Pancreatic Cancer: Recent Progress

Nano-drug delivery systems integrated with low radiation doses for enhanced therapeutic efficacy in cancer treatment

BACKGROUND

Precision medicine is an emerging field that includes tumor-targeted delivery and tumor microenvironment. This review explores the synergistic potential of combining nano-drug delivery systems with low radiation doses to achieve optimized therapeutic outcomes, particularly in the context of cancer treatment. Nanoparticle-based drug carriers offer precise and targeted delivery, enhancing the therapeutic index of anticancer agents. The use of lower radiation doses has become a focus in radiation oncology to minimize off-target effects on healthy tissues in palliation treatment with high-target volume lesions.

AIM

To conduct a bibliometric review of nanomedicine and glioblastoma (GBM), all relevant studies from the last two decades were included.

METHODS

The search strategy comprised the keywords ”nanomedicine “and “glioblastoma” in the title and/or abstract. All English-language documents from 1 January 2000 to 31 December 2023 were considered for the analysis. R code (version 4.2.0) with R Studio (version 2022.12.0-353) and the Bibliometrix package (version 4.0.1) were used for the analysis. A total of 680 documents were collected.

RESULTS

We analyzed the bibliometric features of nanomedicine in glioma. With the limitations of the research, our analysis aims to highlight the increasing interest of researchers in the precision medicine field in GBM treatment and lead us to suggest further studies focusing on the association between nanomedicine and radiotherapy.

CONCLUSION

Due to the poor prognosis associated with GBM, new therapeutic approaches are necessary. There is an increasing interest in precision medicine, which includes nanomedicine and radiotherapy, for GBM treatment. This integration enhances the efficacy of targeted treatments and provides a promising avenue for reducing adverse effects, signifying a notable advancement in precision oncology.

Comprehensive review of drug resistance in mammalian cancer stem cells: implications for cancer therapy

Cancer remains a significant global challenge, and despite the numerous strategies developed to advance cancer therapy, an effective cure for metastatic cancer remains elusive. A major hurdle in treatment success is the ability of cancer cells, particularly cancer stem cells (CSCs), to resist therapy. These CSCs possess unique abilities, including self-renewal, differentiation, and repair, which drive tumor progression and chemotherapy resistance. The resilience of CSCs is linked to certain signaling pathways. Tumors with pathway-dependent CSCs often develop genetic resistance, whereas those with pathway-independent CSCs undergo epigenetic changes that affect gene regulation. CSCs can evade cytotoxic drugs, radiation, and apoptosis by increasing drug efflux transporter activity and activating survival mechanisms. Future research should prioritize the identification of new biomarkers and signaling molecules to better understand drug resistance. The use of cutting-edge approaches, such as bioinformatics, genomics, proteomics, and nanotechnology, offers potential solutions to this challenge. Key strategies include developing targeted therapies, employing nanocarriers for precise drug delivery, and focusing on CSC-targeted pathways such as the Wnt, Notch, and Hedgehog pathways. Additionally, investigating multitarget inhibitors, immunotherapy, and nanodrug delivery systems is critical for overcoming drug resistance in cancer cells.

Strategic Developments in Polymer-Functionalized Liposomes for Targeted Colon Cancer Therapy: An Updated Review of Clinical Trial Data and Future Horizons

Liposomes, made up of phospholipid bilayers, are efficient nanocarriers for drug delivery because they can encapsulate both hydrophilic and lipophilic drugs. Conventional cancer treatments sometimes involve considerable toxicities and adverse drug reactions (ADRs), which limits their clinical value. Despite liposomes' promise in addressing these concerns, clinical trials have revealed significant limitations, including stability, targeted distribution, and scaling challenges. Recent clinical trials have focused on enhancing liposome formulations to increase therapeutic efficacy while minimizing negative effects. Notably, the approval of liposomal medications like Doxil demonstrates their potential in cancer treatment. However, the intricacy of liposome preparation and the requirement for comprehensive regulatory approval remain substantial impediments. Current clinical trial updates show continued efforts to improve liposome stability, targeting mechanisms, and payload capacity in order to address these issues. The future of liposomal drug delivery in cancer therapy depends on addressing these challenges in order to provide patients with more effective and safer treatment alternatives.

Fungi-Derived Bioactive Compounds as Potential Therapeutic Agents for Pancreatic Cancer: A Systematic Review

Pancreatic cancer (PC) is one of the tumors with the lowest 5-year survival rate worldwide due to late diagnosis and lack of effective therapy. Because of this, it is necessary to discover new ways of treatment to increase the quality of life of patients. In this context, the secondary metabolites of several fungi have been shown as a possible therapeutic strategy in several types of cancer, such as colorectal cancer, being able to trigger their action through the induction of apoptosis. The objective was to perform a systematic review process to analyze the studies carried out during the last ten years using secondary metabolites derived from fungi as antitumor treatment against PC. After the search process in three databases (PubMed, SCOPUS, and Web of Science) a total of 199 articles were found, with 27 articles finally being included after screening. The results extracted from this systematic review process made it possible to determine the existence of bioactive compounds extracted from fungi that have been effective in in vitro and in vivo conditions and that may be applicable as a possible therapy to avoid drug resistance in PC, one of the major problems of this disease.

Anti-Colon Cancer Activity of Copper-Doped Folate Carbon Dots/MnO2 Complexes Based on Oxygenation and Immune-Enhancing Effects

In clinical practice, the treatment of colon cancer is faced with the dilemma of metastasis and recurrence, which is related to immunosuppression and hypoxia. Immune checkpoint blockade (ICB) is a negative regulatory pathway of immunity. Immune checkpoint blockade (ICB) is an important immunotherapy method. However, inadequate immunogenicity reduces the overall response rate of ICB. In this study, a tumor microenvironment-responsive nanomedicine (Cu-FACD@MnO2@FA) was prepared to increase host immune response and increase intracellular oxygen levels. Cu-FACD@MnO2@FA preferentially enriched at the tumor site, combined with the immune checkpoint inhibitor alpha PD-L1, induced sufficient immunogenicity to treat colon cancer. Immunofluorescence detection of tumor cells and tissues showed that the expression of hypoxa-inducing factor 1α was significantly down-regulated after treatment and the expression of immunoactivity-related proteins was significantly changed. In vivo treatment in a bilateral tumor mouse model showed complete ablation of the primary tumor and efficient inhibition of the distal tumor. In this study, for the first time, the oxygenation effects of MnO2-coated Cu-doped carbon dots and chemodynamic therapy and a strategy of combining with immuno-blocking therapy were used for treating colon cancer.

Camptothesome-based combination nanotherapeutic regimen for improved colorectal cancer immunochemotherapy

Camptothesome is a sphingomyelin-conjugated camptothecin (SM-CSS-CPT) nanovesicle that fortified the therapeutic delivery of CPT in diverse cancer types. To mitigate the Camptothesome-induced IDO1 negative feedback mechanism, we had co-encapsulated, indoximod (IND, IDO1 inhibitor) into Camptothesome using doxorubicin-derived IND (DOX-IND). To maximize the therapeutic potential of DOX-IND/Camptothesome, herein, we first dissected the synergistic drug ratio (DOX-IND/SM-CSS-CPT) via systematical in vitro screening. DOX-IND/Camptothesome with optimal drug ratio synchronized in vivo drug delivery with significantly higher tumor uptake compared to free drugs. This optimum DOX-IND/Camptothesome outperformed the combination of Camptothesome, Doxil and IND or other IDO1 inhibitors (BMS-986205 or epacadostat) in treating mice bearing late-stage MC38 tumors, and combination with immune checkpoint blockade (ICB) enabled it to eradicate 60 % of large tumors. Further, this optimized co-delivery Camptothesome beat Folfox and Folfiri, two first-line combination chemotherapies for colorectal cancer in antitumor efficacy and exhibited no side effects as compared to the severe systemic toxicities associated with Folfox and Folfiri. Finally, we demonstrated that the synergistic DOX-IND/Camptothesome was superior to the combined use of Onivyde + Doxil + IND in curbing the advanced orthotopic CT26-Luc tumors and eliminated 40 % tumors with complete metastasis remission when cooperated with ICB, eliciting stronger anti-CRC immune responses and greater reversal of immunosuppression. These results corroborated that with precise optimal synergistic drug ratio, the therapeutic potential of DOX-IND/Camptothesome can be fully unleased, which warrants further clinical investigation to benefit the cancer patients.

Hyaluronic acid-functionalized graphene-based nanohybrids for targeted breast cancer chemo-photothermal therapy

Nanomaterials' application in cancer therapy has been driven by their ability to encapsulate chemotherapeutic drugs as well as to reach the tumor site. Nevertheless, nanomedicines' translation has been limited due to their lack of specificity towards cancer cells. Although the nanomaterials' surface can be coated with targeting ligands, such has been mostly achieved through non-covalent functionalization strategies that are prone to premature detachment. Notwithstanding, cancer cells often establish resistance mechanisms that impair the effect of the loaded drugs. This bottleneck may be addressed by using near-infrared (NIR)-light responsive nanomaterials. The NIR-light triggered hyperthermic effect generated by these nanomaterials can cause irreversible damage to cancer cells or sensitize them to chemotherapeutics' action. Herein, a novel covalently functionalized targeted NIR-absorbing nanomaterial for cancer chemo-photothermal therapy was developed. For such, dopamine-reduced graphene oxide nanomaterials were covalently bonded with hyaluronic acid, and then loaded with doxorubicin (DOX/HA-DOPA-rGO). The produced nanomaterials showed suitable physicochemical properties, high encapsulation efficiency, and photothermal capacity. The in vitro studies revealed that the nanomaterials are cytocompatible and that display an improved uptake by the CD44-overexpressing breast cancer cells. Importantly, the combination of DOX/HA-DOPA-rGO with NIR light reduced breast cancer cells' viability to just 23 %, showcasing their potential chemo-photothermal therapy.

Reprogramming the pancreatic cancer stroma and immune landscape by a silicasome nanocarrier delivering nintedanib, a protein tyrosine kinase inhibitor

The prevailing desmoplastic stroma and immunosuppressive microenvironment within pancreatic ductal adenocarcinoma (PDAC) pose substantial challenges to therapeutic intervention. Despite the potential of protein tyrosine kinase (PTK) inhibitors in mitigating the desmoplastic stromal response and enhancing the immune milieu, their efficacy is curtailed by suboptimal pharmacokinetics (PK) and insufficient tumor penetration. To surmount these hurdles, we have pioneered a novel strategy, employing lipid bilayer-coated mesoporous silica nanoparticles (termed "silicasomes") as a carrier for the delivery of Nintedanib. Nintedanib, a triple PTK inhibitor that targets vascular endothelial growth factor, platelet-derived growth factor and fibroblast growth factor receptors, was encapsulated in the pores of silicasomes via a remote loading mechanism for weak bases. This innovative approach not only enhanced pharmacokinetics and intratumor drug concentrations but also orchestrated a transformative shift in the desmoplastic and immune landscape in a robust orthotopic KRAS-mediated pancreatic carcinoma (KPC) model. Our results demonstrate attenuation of vascular density and collagen content through encapsulated Nintedanib treatment, concomitant with significant augmentation of the CD8+/FoxP3+ T-cell ratio. This remodeling was notably correlated with tumor regression in the KPC model. Strikingly, the synergy between encapsulated Nintedanib and anti-PD-1 immunotherapy further potentiated the antitumor effect. Both free and encapsulated Nintedanib induced a transcriptional upregulation of PD-L1 via the extracellular signal-regulated kinase (ERK) pathway. In summary, our pioneering approach involving the silicasome carrier not only improved antitumor angiogenesis but also profoundly reshaped the desmoplastic stromal and immune landscape within PDAC. These insights hold excellent promise for the development of innovative combinatorial strategies in PDAC therapy.

Tectorigenin Inhibits Glycolysis-induced Cell Growth and Proliferation by Modulating LncRNA CCAT2/miR-145 Pathway in Colorectal Cancer

BACKGROUND

Colorectal cancer (CRC) places a heavy burden on global health. Tectorigenin (Tec) is a type of flavonoid-based compound obtained from the Chinese medical herb Leopard Lily Rhizome. It was found to exhibit remarkable anti-tumor properties in previous studies. However, the effect and molecular mechanisms of Tec in colorectal cancer have not been reported.

OBJECTIVE

The objective of this study was to explore the action of Tec in proliferation and glycolysis in CRC and the potential mechanism with regard to the long non-coding RNA (lncRNA) CCAT2/micro RNA-145(miR-145) pathway in vitro and in vivo .

METHODS

The anti-tumor effect of Tec in CRC was examined in cell and animal studies, applying Cell Counting Kit-8 (CCK-8) assay as well as xenograft model experiments. Assay kits were utilized to detect glucose consumption and lactate production in the supernatant of cells and animal serum. The expression of the glycolysis-related proteins was assessed by Western Blotting, and levels of lncRNA CCAT2 and miR-145 in CRC tissue specimens and cells were assessed by realtime quantitative PCR (RT-qPCR).

RESULTS

Tec significantly suppressed cell glycolysis and proliferative rate in CRC cells. It could decrease lncRNA CCAT2 in CRC cells but increase the expression of miR-145. LncRNA CCAT2 overexpression or inhibition of miR-145 could abolish the inhibitive effects of Tec on the proliferation and glycolysis of CRC cells. The miR-145 mimic rescued the increased cell viability and glycolysis levels caused by lncRNA CCAT2 overexpression. Tec significantly inhibited the growth and glycolysis of CRC xenograft tumor. The expression of lncRNA CCAT2 decreased while the expression of miR-145 increased after Tec treatment in vivo.

CONCLUSION

Tec can inhibit the proliferation and glycolysis of CRC cells through the lncRNA CCAT2/miR-145 axis. Altogether, the potential targets discovered in this research are of great significance for CRC treatment and new drug development.

Folic acid-chitosan functionalized polymeric nanocarriers to treat colon cancer

In the present study, polymeric nanoparticles loaded with IRI and quercetin, a p-gp inhibitor, were developed to target folate receptors expressed by colon cancer cells for oral targeted delivery. This work reports the development of PNPs with an entrapment efficiency of 41.26 ± 0.56 % for IRI and 55.83 ± 4.51 for QT. PNPs were further surface modified using chitosan-folic acid conjugates for better targetability to obtain folic acid-chitosan coated nanoparticles. DLS and FeSEM revealed particles in the nanometric size range with spherical morphology, while FTIR and DSC provided details on their structure and encapsulation. In vitro drug release studies confirmed a sustained release pattern of IRI and QT, while cell line studies confirmed the superiority of C-FA-PNPs when tested on Caco2 cells. Pharmacodynamic studies in colon cancer induced rats showed similar efficacy for PNPs and C-FA-PNPs. Further examination from a bio-distribution study in healthy rats, revealed the failure of C-FA-PNPs to deliver the drugs to the colon adequately, while the PNPs improved the available concentration of IRI at the colon by almost 1.8 folds when compared to the available marketed product. Hence, the developed PNP formulation sticks out as a plausible substitute for the intravenous dosage forms of IRI which have been conventionally prevailing.

Tailoring renal-clearable zwitterionic cyclodextrin for colorectal cancer-selective drug delivery

Although cyclodextrin-based renal-clearable nanocarriers have a high potential for clinical translation in targeted cancer therapy, their designs remain to be optimized for tumour retention. Here we report on the design of a tailored structure for renal-clearable zwitterionic cyclodextrin for colorectal cancer-selective drug delivery. Twenty cyclodextrin derivatives with different charged moieties and spacers are synthesized and screened for colloidal stability. The resulting five candidates are evaluated for biodistribution and an optimized structure is identified. The optimized cyclodextrin shows a high tumour accumulation and is used for delivery of doxorubicin and ulixertinib. Higher tumour accumulation and tumour penetration facilitates tumour elimination. The improved antitumour efficacy is demonstrated in heterotopic and orthotopic colorectal cancer models.

Liposome encapsulated anticancer drugs on autophagy in cancer cells - current and future perspective

Autophagy act as a double-edged sword in cancer with both tumor promoting and inhibiting roles. Under normal conditions of autophagy, the damaged cell organelles and other debris degrade inside the lysosome to provide energy and macromolecular precursors. However, enhanced autophagy can lead to apoptosis and programmed cell death highlighting its significance in cancer therapy. Liposome-based drug delivery systems for treating cancer patients have significant advantages over their non-formulated or free drug counterparts which could be effectively used to manipulate autophagy pathway in cancer patients. In the current review, drug uptake by the cells and its role in autophagy-mediated cancer cell death are discussed. Besides, the challenges and translational difficulties associated with the use of liposome-based chemotherapeutic drugs in clinical trials and in biomedical applications are also discussed.

Targeted degradation of ABCG2 for reversing multidrug resistance by hypervalent bispecific gold nanoparticle-anchored aptamer chimeras

Hypervalent bispecific gold nanoparticle-anchored aptamer chimeras (AuNP-APTACs) were designed as a new tool of lysosome-targeting chimeras (LYTACs) for efficient degradation of the ATP-binding cassette, subfamily G, isoform 2 protein (ABCG2) to reverse multidrug resistance (MDR) of cancer cells. The AuNP-APTACs could effectively increase the accumulation of drugs in drug-resistant cancer cells and provide comparable efficacy to small-molecule inhibitors. Thus, this new strategy provides a new way to reverse MDR, holding great promise in cancer therapy.

Discovery of new potent lysine specific histone demythelase-1 inhibitors (LSD-1) using structure based and ligand based molecular modelling and machine learning

Lysine-specific histone demethylase 1 (LSD-1) is an epigenetic enzyme that oxidatively cleaves methyl groups from monomethyl and dimethyl Lys4 of histone H3 and is highly overexpressed in different types of cancer. Therefore, it has been widely recognized as a promising therapeutic target for cancer therapy. Towards this end, we employed various Computer Aided Drug Design (CADD) approaches including pharmacophore modelling and machine learning. Pharmacophores generated by structure-based (SB) (either crystallographic-based or docking-based) and ligand-based (LB) (either supervised or unsupervised) modelling methods were allowed to compete within the context of genetic algorithm/machine learning and were assessed by Shapley additive explanation values (SHAP) to end up with three successful pharmacophores that were used to screen the National Cancer Institute (NCI) database. Seventy-five NCI hits were tested for their LSD-1 inhibitory properties against neuroblastoma SH-SY5Y cells, pancreatic carcinoma Panc-1 cells, glioblastoma U-87 MG cells and in vitro enzymatic assay, culminating in 3 nanomolar LSD-1 inhibitors of novel chemotypes.

Camptothesome Potentiates PD-L1 Immune Checkpoint Blockade for Improved Metastatic Triple-Negative Breast Cancer Immunochemotherapy

In this study, we focus on investigating the therapeutic effects of camptothesome on treating metastatic triple-negative breast cancer (TNBC). We elucidate that camptothesome elicited stronger immunogenic cell death (ICD) compared to free camptothecin (CPT) and Onivyde in 4T1 TNBC cells. In addition, camptothesome is mainly internalized by the 4T1 and MDA-MB-231 cells through clathrin-mediated endocytosis based on the results of flow cytometry. Through real-time Lago optical imaging, camptothesome shows excellent tumor-targeting efficiency in orthotopic TNBC tumors. We demonstrate that camptothesome can upregulate programmed death-ligand 1 (PD-L1) in 4T1 tumors in an interferon gamma (IFN-γ)-dependent manner. Furthermore, the anti-TNBC efficacy studies reveal that camptothesome is superior to Onivyde and markedly potentiates PD-L1 immune checkpoint blockade therapy with complete lung metastasis remission in an orthotopic 4T1-Luc2 tumor model. This combination therapy eliciting robust cytotoxic T lymphocytes (CTL) response via boosting tumor-infiltrating cluster of differentiation 8 (CD8), calreticulin (CRT), high mobility group box 1 protein (HMGB-1), low-density lipoprotein receptor-related protein 1 (LRP1), IFN-γ, and granzyme B. Our work corroborates the promise of camptothesome in favorably modulating tumor immune microenvironment via inducing ICD to fortify the PD-L1 checkpoint blockade therapy for improved treatment of intractable TNBC.

Development of doped ZnO-based biomimicking and tumor-targeted nanotheranostics to improve pancreatic cancer treatment

Despite different nanomaterials were developed so far against cancer, their potential drawbacks are still scarcely considered. The off-target delivery of a therapeutic compound, as well as the non-specific uptake of these nanomaterials by healthy tissues or organs, and their potential immunogenicity are some of the major issues that still have to be faced prior to a successful clinical translation. This work aims to develop an innovative theranostic, biocompatible, and drug-loaded nanoconstruct based on Gadolinium-doped Zinc Oxide (ZnO-Gd) nanocrystals (NCs), focusing on one of the most lethal diseases, i.e., pancreatic cancer. The use of zinc oxide is motivated by the huge potential of this nanomaterial already demonstrated for in vitro and in vivo applications, while the Gadolinium doping confers magnetic properties useful for diagnostics. Furthermore, an innovative biomimetic shell is here used to coat the NCs: it is composed of a lipid bilayer made from extracellular vesicles (EVs) combined with other synthetic lipids and a peptide targeting the pancreatic tumor microenvironment. To complete the nanoconstruct therapeutic function, Gemcitabine, a first-line drug for pancreatic cancer treatment, was adsorbed on the ZnO-Gd NCs prior to the coating with the above-mentioned lipidic shell. The aim of this work is thus to strongly enhance the therapeutic capability of the final nanoconstruct, providing it with high biocompatibility, colloidal stability in biological media, efficient cargo loading and release properties, as well as active targeting for site-selective drug delivery. Furthermore, the magnetic properties of the ZnO-Gd NCs core can in future allow efficient in situ bioimaging capabilities based on Magnetic Resonance Imaging technique. The obtained nanoconstructs were tested on two different pancreatic cancer cell lines, i.e., BxPC-3 and the metastatic AsPC-1, proving high cell internalization levels, mediated by the targeting peptide exposed on the nanoconstruct. Cellular cytotoxicity assay performed on both cell lines dictated ~ 20% increased cell killing efficacy of Gemcitabine when delivered through the nanoconstruct rather than as a free drug. Taken together, our designed theranostic nanoconstruct can have a significant impact on the standard treatment of pancreatic cancer.

Targeting cancer stem cells with polymer nanoparticles for gastrointestinal cancer treatment

Nanomaterials are developing rapidly in the medical field, bringing new hope for treating various refractory diseases. Among them, polymer nanomaterials, with their excellent properties, have been used to treat various diseases, such as malignant tumors, diabetes, and nervous system diseases. Gastrointestinal cancer is among the cancers with the highest morbidity and mortality worldwide. Cancer stem cells are believed to play an important role in the occurrence and development of tumors. This article summarizes the characteristics of gastrointestinal cancer stem cells and reviews the latest research progress in treating gastrointestinal malignant tumors using polymer nanoparticles to target cancer stem cells. In addition, the review article highlights the potential of polymer nanoparticles in targeting gastrointestinal cancer stem cells.

Camptothesome elicits immunogenic cell death to boost colorectal cancer immune checkpoint blockade

Camptothesome is an innovative nanovesicle therapeutic comprising the sphingomyelin-derived camptothecin (CPT) lipid bilayer. In this work, we deciphered that Camptothesome was taken up by colorectal cancer (CRC) cells through primarily the clathrin-mediated endocytotic pathway and displayed the potential of eliciting robust immunogenic cancer cell death (ICD) via upregulating calreticulin, high mobility group box 1 protein (HMGB-1), and adenosine triphosphate (ATP), three hallmarks involved in the induction of ICD. In addition, use of dying MC38 tumor cells treated with Camptothesome as vaccine prevented tumor growth in 60% mice that received subsequent injection of live MC38 cells on the contralateral flank, validating Camptothesome was a legitimate ICD inducer in vivo. Camptothesome markedly reduced the acute bone marrow toxicity and gastrointestinal mucositis associated with free CPT and beat free CPT and Onivyde on anti-CRC efficacy and immune responses in a partially interferon gamma (IFN-γ)-dependent manner. Furthermore, Camptothesome enhanced the efficacy of immune checkpoint inhibitors to shrink late-stage orthotopic MC38 CRC tumors with diminished tumor metastasis and markedly prolonged mice survival.

Glutathione S-Transferase Alpha 4 Promotes Proliferation and Chemoresistance in Colorectal Cancer Cells

Glutathione S-transferase alpha 4 (GSTA4) is a phase II detoxifying enzyme that is overexpressed in colorectal cancer (CRC) and regulated by the oncogenic transcription factor AP-1. However, the role of GSTA4 in these CRC cells remains unclear. In this study, we investigated the roles of GSTA4 in the CRC cells by inactivating GSTA4 in HCT116 human CRC cells (Defined as HCT116^ΔGSTA4) using the CRISPR/Cas9 gene editing. Cell proliferation, clonogenicity, and susceptibility to chemotherapeutic drugs were analyzed in vitro and in a xenograft model. The results showed that loss of GSTA4 significantly decreased cell proliferation and clonogenicity, whereas it increased intracellular reactive oxygen species and cell susceptibility to 5-fluorouracil (5-FU) and oxaliplatin. Additionally, exposure of HCT116^ΔGSTA4 cells to 5-FU increased the expression of γH2AX, a hallmark of double-stranded DNA breaks. In contrast, no remarkably increased γH2AX was noted in oxaliplatin-treated HCT116^ΔGSTA4 cells compared with HCT116 cells. Moreover, loss of GSTA4 blocked the AKT and p38 MAPK pathways, leading to proliferative suppression. Finally, the xenograft model showed decreased tumor size for HCT116^ΔGSTA4 cells compared with HCT116 cells, confirming in vitro findings. These findings suggest that GSTA4 is capable of promoting proliferation, tumorigenesis, and chemoresistance and is a potential target for CRC therapy.

Recent advances in targeted drug delivery systems for resistant colorectal cancer

Colorectal cancer (CRC) is one of the deadliest cancers in the world, the incidences and morality rate are rising and poses an important threat to the public health. It is known that multiple drug resistance (MDR) is one of the major obstacles in CRC treatment. Tumor microenvironment plus genomic instability, tumor derived exosomes (TDE), cancer stem cells (CSCs), circulating tumor cells (CTCs), cell-free DNA (cfDNA), as well as cellular signaling pathways are important issues regarding resistance. Since non-targeted therapy causes toxicity, diverse side effects, and undesired efficacy, targeted therapy with contribution of various carriers has been developed to address the mentioned shortcomings. In this paper the underlying causes of MDR and then various targeting strategies including exosomes, liposomes, hydrogels, cell-based carriers and theranostics which are utilized to overcome therapeutic resistance will be described. We also discuss implication of emerging approaches involving single cell approaches and computer-aided drug delivery with high potential for meeting CRC medical needs.

Gemcitabine-Loaded Albumin Nanoparticle Exerts An Antitumor Effect on Gemcitabine-Resistant Pancreatic Cancer Cells Induced by MDR1 and MRP1 Overexpression in Vitro

Purpose

Gemcitabine (GEM) is the first-line chemotherapeutic drug for pancreatic cancer treatment in clinical practice. However, many reasons can reduce the efficacy of GEM, among which the high expression of ATP-binding cassette (ABC) transporters is a significant factor. In this study, we aimed to investigate the antitumor effect of gemcitabine-loaded human serum albumin nanoparticle (GEM-HSA-NP) on GEM-resistant pancreatic cancer cells induced by the high expression of ABC transporters, namely multidrug resistance protein 1/P-gp/ABCB1 (MDR1) and multidrug resistance-associated protein 1/ ABCC1 (MRP1).

Methods

MDR1 and MRP1 were stably overexpressed via lentiviral transduction in the pancreatic cancer cell lines BxPC3 and PANC1. Proliferation inhibition assays, cell cycle arrest and apoptosis analyses were conducted to examine the antitumor effect of GEM-HSA-NP. In addition, intracellular ATP levels were determined to explore the potential mechanisms implicated preliminarily.

Results

When administered to GEM-resistant cancer cells, GEM-HSA-NP displayed its antitumor effect by promoting the inhibition of proliferation, cell cycle arrest, and apoptosis induction. Intracellular ATP depletion, caused by the albumin component of GEM-HSA-NP was proposed to be potentially involved in the modulation of ABC transporter activity.

Conclusion

GEM-HSA-NP can effectively overcome GEM-resistance induced by MDR1 and MRP1 overexpression, which highlights its potential value in a clinical setting.

Identification of New Regulators of Pancreatic Cancer Cell Sensitivity to Oxaliplatin and Cisplatin

The chemoresistance of tumor cells is one of the most urgent challenges in modern oncology and in pancreatic cancer, in which this problem is the most prominent. Therefore, the identification of new chemosensitizing co-targets may be a path toward increasing chemotherapy efficacy. In this work, we performed high-performance in vitro knockout CRISPR/Cas9 screening to find potential regulators of the sensitivity of pancreatic cancer. For this purpose, MIA PaCa-2 cells transduced with two sgRNA libraries (“cell cycle/nuclear proteins genes” and “genome-wide”) were screened by oxaliplatin and cisplatin. In total, 173 candidate genes were identified as potential regulators of pancreatic cancer cell sensitivity to oxaliplatin and/or cisplatin; among these, 25 genes have previously been reported, while 148 genes were identified for the first time as potential platinum drug sensitivity regulators. We found seven candidate genes involved in pancreatic cancer cell sensitivity to both cisplatin and oxaliplatin. Gene ontology enrichment analysis reveals the enrichment of single-stranded DNA binding, damaged DNA binding pathways, and four associated with NADH dehydrogenase activity. Further investigation and validation of the obtained results by in vitro, in vivo, and bioinformatics approaches, as well as literature analysis, will help to identify novel pancreatic cancer platinum sensitivity regulators.

Do Lipid-based Nanoparticles Hold Promise for Advancing the Clinical Translation of Anticancer Alkaloids?

Since the commercialization of morphine in 1826, numerous alkaloids have been isolated and exploited effectively for the betterment of mankind, including cancer treatment. However, the commercialization of alkaloids as anticancer agents has generally been limited by serious side effects due to their lack of specificity to cancer cells, indiscriminate tissue distribution and toxic formulation excipients. Lipid-based nanoparticles represent the most effective drug delivery system concerning clinical translation owing to their unique, appealing characteristics for drug delivery. To the extent of our knowledge, this is the first review to compile in vitro and in vivo evidence of encapsulating anticancer alkaloids in lipid-based nanoparticles. Alkaloids encapsulated in lipid-based nanoparticles have generally displayed enhanced in vitro cytotoxicity and an improved in vivo efficacy and toxicity profile than free alkaloids in various cancers. Encapsulated alkaloids also demonstrated the ability to overcome multidrug resistance in vitro and in vivo. These findings support the broad application of lipid-based nanoparticles to encapsulate anticancer alkaloids and facilitate their clinical translation. The review then discusses several limitations of the studies analyzed, particularly the discrepancies in reporting the pharmacokinetics, biodistribution and toxicity data. Finally, we conclude with examples of clinically successful encapsulated alkaloids that have received regulatory approval and are undergoing clinical evaluation.