Rapamycin Liposomes Combined with 5-Fluorouracil Inhibits Angiogenesis and Tumor Growth of APC (Min/+) Mice and AOM/DSS-Induced Colorectal Cancer Mice

Targeted co-delivery of rapamycin and oxaliplatin by liposomes suppresses tumor growth and metastasis of colorectal cancer

The activation of tumor cell immunogenicity through oxaliplatin (OXP)-induced immunogenic cell death (ICD) has significant implications in cancer treatment. However, the anti-tumor effect of OXP monotherapy still has many shortcomings, and the systemic administration of OXP leads to low drug concentration at the tumor site, which is susceptible to systemic toxic side effects. In this study, a combined therapeutic strategy using folate-modified nanoliposomes co-delivered with rapamycin (Rapa) and OXP (abbreviated as FA@R/O Lps) is proposed for the treatment of colorectal cancer (CRC). Rapa and OXP can directly inhibit tumor cell proliferation and induce apoptosis. OXP induces ICD by triggering the release of danger signals, such as HMGB1, ATP, and calreticulin. FA@R/O Lps with a particle size of about 134.1±1.8 nm and a small dispersion were successfully prepared. This novel liposomal system can be used to target and increase drug accumulation in tumors. In-vivo experiments showed that FA@R/O Lps successfully inhibit CRC growth and liver metastasis, and simultaneously reduce off-target toxicity. In particular, FA@R/O Lps showed greater therapeutic effects than free Rapa/OXP and R/O Lps. Taken together, this study provides a novel combination of Rapa and OXP, and a nano-delivery system for enhanced anti-CRC efficacy. The results suggest that FA@R/O Lps could be a promising strategy for the treatment of CRC.

Nanoliposomes Encapsulated Rapamycin/Resveratrol to Induce Apoptosis and Ferroptosis for Enhanced Colorectal Cancer Therapy

OBJECTIVES

Monotherapy is often ineffective for treating colorectal cancer. In this study, we developed PEG-modified liposomes loaded with rapamycin (Rapa) and resveratrol (Res) (Rapa/Res liposomes, or RRL) to investigate their therapeutic potential in colorectal cancer.

METHODS

RRL were constructed using the reversed-phase evaporation method. We assessed the cytotoxicity, apoptosis, and ferroptotic effects of RRL on colorectal cancer HCT116 cells. The anti-tumor efficacy of RRL was evaluated in HCT116 xenograft mice.

RESULTS

RRL had a particle size of 86.67 ± 1.10 nm and a zeta potential of -33.13 ± 0.49 mV. The coloaded formulation demonstrated satisfactory performance both in vitro and in vivo, resulting in increased cytotoxicity to HCT116 cells and significant suppression of HCT116 xenografts tumor growth. Mechanically, RRL significantly increased the apoptosis rate of HCT116 cells, induced ROS accumulation in tumor cells, and effectively downregulated the expression of the ferroptosis-associated proteins GPX4 and SLC7A11, demonstrating its superior efficacy compared to that of Rapa liposomes (Rapa/Lps) or Res liposomes (Res/Lps) alone.

CONCLUSION

Coloading Rapa and Res into liposomes to promote apoptosis and ferroptosis in tumor cells represents a promising strategy for the treatment of colorectal cancer.

MAPKAP1 orchestrates macrophage polarization and lipid metabolism in fatty liver-enhanced colorectal cancer

Various factors, including fatty liver and macrophage alterations, influence colorectal cancer (CRC). This study explores the mechanistic role of fatty liver in CRC progression, focusing on macrophage polarization and lipid metabolism. A murine fatty liver model was created with a high-fat diet (HFD), and CRC was induced using AOM and DSS. Single-cell transcriptome sequencing (scRNA-seq) identified MAPKAP1 as a critical gene promoting CRC via M2 macrophage polarization and lipid metabolism reprogramming. Prognosis analysis on the TCGA-CRC dataset confirmed MAPKAP1's significance. In vitro and in vivo experiments demonstrated that EVs from fatty liver cells enhanced MAPKAP1 expression, accelerating CRC development and metastasis. HFD exacerbated CRC, but fatty acid inhibitors delayed progression. Fatty liver upregulates MAPKAP1, driving M2 macrophage polarization and lipid metabolism changes, worsening CRC. These findings suggest potential therapeutic strategies for CRC, particularly targeting lipid metabolism and macrophage-mediated tumor promotion.

Rapamycin circumvents anti PD-1 therapy resistance in colorectal cancer by reducing PD-L1 expression and optimizing the tumor microenvironment

The unresectable or postoperative recurrence of advanced metastatic colorectal cancer (CRC) is the difficulty of its clinical management, and pharmacological therapy is the main source of benefit. Immune checkpoint inhibitors are therapeutic options but are effective in approximately 5 % of patients with deficient mismatch repair (MMR)/microsatellite instability CRC and are ineffective in patients with MMR-proficient (pMMR)/microsatellite stable (MSS) CRCs, which may be associated with the tumor microenvironment (TME). Here, we propose a new combination strategy and evaluate the efficacy of rapamycin (Rapa) combined with anti-PD-1 (αPD-1) in CT26 tumor-bearing mice, azoxymethane (AOM)/dextran sodium sulfate (DSS) inflammation-associated CRC mice, CT26-Luc tumor-bearing mice with postoperative recurrence, and CT26 liver metastasis mice. The results revealed that Rapa improved the therapeutic effect of αPD-1 and effectively inhibited colorectal carcinogenesis, postoperative recurrence, and liver metastasis. Mechanistically, Rapa improved the anticancer effect of αPD-1, associated with Rapa reprograming of the immunosuppressive TME. Rapa effectively depleted α-SMA+ cancer-associated fibroblasts and degraded collagen in the tumor tissue, increasing T lymphocyte infiltration into the tumor tissue. Rapa induced the downregulation of programed cell death 1 ligand 1 (PD-L1) protein and transcript levels in CT26 cells, which may be associated with the inhibition of the mTOR/P70S6K signaling axis. Furthermore, co-culture of tumor cells and CD8+ T lymphocytes demonstrated that Rapa-induced PD-L1 downregulation in tumor cells increased spleen-derived CD8+ T lymphocyte activation. Therefore, Rapa improves the anti-tumor effect of αPD-1 in CRCs, providing new ideas for its use to improve combinatorial strategies for anti-PD-1 immunotherapy.

Multifunctional and stimuli-responsive liposomes in hepatocellular carcinoma diagnosis and therapy

Hepatocellular carcinoma (HCC) is the most prevalent type of liver cancer, mainly occurring in Asian countries with an increased incidence rate globally. Currently, several kinds of therapies have been deployed for HCC therapy including surgical resection, chemotherapy, radiotherapy and immunotherapy. However, this tumor is still incurable, requiring novel strategies for its treatment. The nanomedicine has provided the new insights regarding the treatment of cancer that liposomes as lipid-based nanoparticles, have been widely applied in cancer therapy due to their biocompaitiblity, high drug loading and ease of synthesis and modification. The current review evaluates the application of liposomes for the HCC therapy. The drugs and genes lack targeting ability into tumor tissues and cells. Therefore, loading drugs or genes on liposomes can increase their accumulation in tumor site for HCC suppression. Moreover, the stimuli-responsive liposomes including pH-, redox- and light-sensitive liposomes are able to deliver drug into tumor microenvironment to improve therapeutic index. Since a number of receptors upregulate on HCC cells, the functionalization of liposomes with lactoferrin and peptides can promote the targeting ability towards HCC cells. Moreover, phototherapy can be induced by liposomes through loading phtoosensitizers to stimulate photothermal- and photodynamic-driven ablation of HCC cells. Overall, the findings are in line with the fact that liposomes are promising nanocarriers for the treatment of HCC.

Regulation of Hippo-YAP/CTGF signaling by combining an HDAC inhibitor and 5-fluorouracil in gastric cancer cells

Histone deacetylase (HDAC) inhibitors diminish carcinogenesis, metastasis, and cancer cell proliferation by inducing death in cancer cells. Tissue regeneration and organ development are highly dependent on the Hippo signaling pathway. Targeting the dysregulated hippo pathway is an excellent approach for cancer treatment. According to the results of this study, the combination of panobinostat, a histone deacetylase inhibitor, and 5-fluorouracil (5-FU), a chemotherapy drug, can act synergistically to induce apoptosis in gastric cancer cells. The combination of panobinostat and 5-FU was more effective in inhibiting cell viability than either treatment alone by elevating the protein levels of cleaved PARP and cleaved caspase-9. By specifically targeting E-cadherin, vimentin, and MMP-9, the combination of panobinostat and 5-FU significantly inhibited cell migration. Additionally, panobinostat significantly increased the anticancer effects of 5-FU by activating Hippo signaling (Mst 1 and 2, Sav1, and Mob1) and inhibiting the Akt signaling pathway. As a consequence, there was a decrease in the amount of Yap protein. The combination therapy of panobinostat with 5-FU dramatically slowed the spread of gastric cancer in a xenograft animal model by deactivating the Akt pathway and supporting the Hippo pathway. Since combination treatment exhibits much higher anti-tumor potential than 5-FU alone, panobinostat effectively potentiates the anti-tumor efficacy of 5-FU. As a result, it is believed that panobinostat and 5-FU combination therapy will be useful as supplemental chemotherapy in the future.

Murine models of colorectal cancer: the azoxymethane (AOM)/dextran sulfate sodium (DSS) model of colitis-associated cancer

Background

Colorectal cancer (CRC) is the third most common cancer. It is a heterogeneous disease, including both hereditary and sporadic types of tumors. CRC results from complex interactions between various genetic and environmental factors. Inflammatory bowel disease is an important risk factor for developing CRC. Despite growing understanding of the CRC biology, preclinical models are still needed to investigate the etiology and pathogenesis of the disease, as well as to find new methods of treatment and prevention.

Objectives

The purpose of this review is to describe existing murine models of CRC with a focus on the models of colitis-associated CRC. This manuscript could be relevant for experimental biologists and oncologists.

Methodology

We checked PubMed and Google from 01/2018 to 05/2023 for reviews of CRC models. In addition, we searched PubMed from 01/2022 to 01/2023 for articles using the azoxymethane (AOM)/dextran sulfate sodium (DSS) CRC model.

Results

Existing murine models of CRC include spontaneous, genetically engineered, transplantation, and chemically induced models. For the study of colitis-associated cancer (CAC), the AOM/DSS model is predominantly used. This model is very similar in histological and molecular characteristics to the human CAC, and is highly reproducible, inexpensive, and easy to use. Despite its popularity, the AOM/DSS model is not standardized, which makes it difficult to analyze and compare data from different studies.

Conclusions

Each model demonstrates particular advantages and disadvantages, and allows to reproduce different subtypes or aspects of the pathogenesis of CRC.

Toxic effects of sirolimus and everolimus on the development and behavior of zebrafish embryos

Sirolimus and everolimus have been widely used in children. These mammalian target of rapamycin (mTOR) inhibitors have shown excellent efficacy not only in organ transplant patients as immunosuppressive agents but also in patients with some other diseases. However, whether mTOR inhibitors can affect the growth and development of children is of great concern. In this study, using zebrafish models, we discovered that sirolimus and everolimus could slow the development of zebrafish, affecting indicators such as survival, hatching, deformities, body length, and movement. In addition to these basic indicators, sirolimus and everolimus had certain slowing effects on the growth and development of the nervous system, blood vessels, and the immune system. These effects were dose dependent. When the drug concentration reached or exceeded 0.5 μM, the impacts of sirolimus and everolimus were very significant. More interestingly, the impact was transient. Over time, the various manifestations of experimental embryos gradually approached those of control embryos. We also compared the effects of sirolimus and everolimus on zebrafish, and we revealed that there was no significant difference between these drugs in terms of their effects. In summary, the dose of sirolimus and everolimus in children should be strictly controlled, and the drug concentration should be monitored over time. Otherwise, drug overdosing may have a certain impact on the growth and development of children.

Multi-targeting liposomal codelivery of cisplatin and rapamycin inhibits pancreatic cancer growth and metastasis through stromal modulation

Pancreatic cancer treatment faces challenges due to drug resistance as well as liver metastasis. As a new strategy for treating pancreatic cancer, combination therapy is now available, but the dense mesenchymal barrier in the tumor tissue blocks drug delivery and impairs its therapeutic efficacy. To address this issue, we prepared an ATF peptide-decorated liposomal co-loaded with cisplatin and rapamycin (ATF@Pt/Rapa Lps), which targets both tumor cells and cancer-associated fibroblasts that express uPAR receptors. In tumor sphere penetration experiments, ATF peptide modified liposomes significantly enhanced deep penetration. More importantly, the ATF@Pt/Rapa Lps disrupted the stroma, as demonstrated by the downregulation of ɑ-SMA, I collagen, and fibronectin protein in vivo and in vitro. In this way, highly effective drug delivery to tumor cells can be achieved. As expected, there was a stronger inhibition of cell proliferation and migration by ATF@Pt/Rapa Lps in vitro compared to free Pt/Rapa and Pt/Rapa Lps. Furthermore, ATF@Pt/Rapa Lps showed greater therapeutic effects in PANC02 transplanted tumor mice and liver metastasis mice models. Ultimately, multi-targeting nanomedicines co-loaded with Rapa and cisplatin may provide a new approach to treating metastatic pancreatic cancer.

Experimental Murine Models for Colorectal Cancer Research

Colorectal cancer (CRC) is the third most prevalent malignancy worldwide and in both sexes. Numerous animal models for CRC have been established to study its biology, namely carcinogen-induced models (CIMs) and genetically engineered mouse models (GEMMs). CIMs are valuable for assessing colitis-related carcinogenesis and studying chemoprevention. On the other hand, CRC GEMMs have proven to be useful for evaluating the tumor microenvironment and systemic immune responses, which have contributed to the discovery of novel therapeutic approaches. Although metastatic disease can be induced by orthotopic injection of CRC cell lines, the resulting models are not representative of the full genetic diversity of the disease due to the limited number of cell lines suitable for this purpose. On the other hand, patient-derived xenografts (PDX) are the most reliable for preclinical drug development due to their ability to retain pathological and molecular characteristics. In this review, the authors discuss the various murine CRC models with a focus on their clinical relevance, benefits, and drawbacks. From all models discussed, murine CRC models will continue to be an important tool in advancing our understanding and treatment of this disease, but additional research is required to find a model that can correctly reflect the pathophysiology of CRC.