Oxaliplatin Enhances the Apoptotic Effect of Mesenchymal Stem Cells, Delivering Soluble TRAIL in Chemoresistant Colorectal Cancer

A key problem in colorectal cancer (CRC) is the development of resistance to current therapies due to the presence of cancer stem cells (CSC), which leads to poor prognosis. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a protein that activates apoptosis in cancer cells through union with TRAIL death receptors. Cell therapies as delivery systems can produce soluble TRAIL (sTRAIL) and full-length TRAIL (flTRAIL), showing a high capacity to produce apoptosis in vitro and in vivo assays. However, the apoptotic activity of TRAIL as monotherapy had limitations, so it is important to explore other ways to enhance susceptibility to TRAIL. This study evaluated the cytotoxic and proapoptotic activity of soluble TRAIL overexpressed by mesenchymal stem cells (MSC) in an oxaliplatin-resistant CRC cell line. Bone marrow-MSC were lentiviral transduced for soluble TRAIL expression. DR5 death receptor expression was determined in Caco-2 and CMT-93 CRC cell lines. Sensitivity to first-line chemotherapies and recombinant TRAIL was evaluated by half-maximal inhibitory concentrations. Cytotoxic and proapoptotic activity of soluble TRAIL-MSC alone and combined with chemotherapy pre-treatment was evaluated using co-cultures. Caco-2 and CMT-93 cell lines expressed 59.08 ± 5.071 and 51.65 ± 11.99 of DR5 receptor and had IC50 of 534.15 ng/mL and 581.34 ng/mL for recombinant murine TRAIL (rmTRAIL), respectively. This finding was classified as moderate resistance to TRAIL. The Caco-2 cell line showed resistance to oxaliplatin and irinotecan. MSC successfully overexpressed soluble TRAIL and induced cancer cell death at a 1:6 ratio in co-culture. Oxaliplatin pre-treatment in the Caco-2 cell line increased the cell death percentage (50%) and apoptosis by sTRAIL. This finding was statistically different from the negative control (p < 0.05), and activity was even higher with the oxaliplatin-flTRAIL combination. Thus, oxaliplatin increases apoptotic activity induced by soluble TRAIL in a chemoresistant CRC cell line.

Mesenchymal Stem Cells Genetically Modified by Lentivirus-Express Soluble TRAIL and Interleukin-12 Inhibit Growth and Reduced Metastasis-Relate Changes in Lymphoma Mice Model

BACKGROUND

Cancer treatment has many side effects; therefore, more efficient treatments are needed. Mesenchymal stem cells (MSC) have immunoregulatory properties, tumor site migration and can be genetically modified. Some proteins, such as soluble TRAIL (sTRAIL) and interleukin-12 (IL-12), have shown antitumoral potential, thus its combination in solid tumors could increase their activity.

MATERIALS AND METHODS

Lentiviral transduction of bone marrow MSC with green fluorescent protein (GFP) and transgenes (sTRAIL and IL-12) was confirmed by fluorescence microscopy and Western blot. Soluble TRAIL levels were quantified by ELISA. Lymphoma L5178Y cells express a reporter gene (GFP/mCherry), and TRAIL receptor (DR5).

RESULTS

An in vivo model showed that combined treatment with MSC expressing sTRAIL+IL-12 or IL-12 alone significantly reduced tumor volume and increased survival in BALB/c mice (p < 0.05) with only one application. However, at the histological level, only MSC expressing IL-12 reduced tumor cell infiltration significantly in the right gastrocnemius compared with the control group (p < 0.05). It presented less tissue dysplasia confirmed by fluorescence and hematoxylin-eosin dye; nevertheless, treatment not inhibited hepatic metastasis.

CONCLUSIONS

MSC expressing IL-12, is or combination with BM-MSC expressing sTRAIL represents an antitumor strategy for lymphoma tumors since they increase survival and reduce tumor development. However, the combination did not show significative additive effect. The localized application did not inhibit metastasis but reduced morphological alterations of tissue associated with liver metastasis.

A combined antitumor strategy of separately transduced mesenchymal stem cells with soluble TRAIL and IFNβ produces a synergistic activity in the reduction of lymphoma and mice survival enlargement

As the understanding of cancer grows, new therapies have been proposed to improve the well-known limitations of current therapies, whose efficiency relies mostly on early detection, surgery and chemotherapy. Mesenchymal stem cells (MSCs) have been introduced as a promissory and effective therapy. This fact is due to several useful features of MSCs, such as their accessibility and easy culture and expansion in vitro, and their remarkable ability for ‘homing’ towards tumors, allowing MSCs to exert their anticancer effects directly into tumors. Additionally, MSCs offer the practicability of being genetically engineered to carry anticancer genes, increasing their specificity and efficacy for fighting tumors. In the present study, the antitumoral efficacy and post-implant survival of mice bearing lymphomas implanted intratumorally were determined using mouse bone marrow-derived (BM)-MSCs transduced with soluble TRAIL (sTRAIL), full length TRAIL (flTRAIL), or interferon β (IFNβ), naïve BM-MSCs, or combinations of these. The percentage of surviving mice was determined once all not-implanted mice succumbed. It was found that the percentage of surviving mice implanted with the combination of MSCs-sTRAIL and MSCs-IFN-β was 62.5%. Lymphoma model achieved 100% fatality in the non-treated group by day 41. On the other hand, the percentage of surviving mice implanted with MSCs-sTRAIL was 50% and with MSCs-INFβ 25%. All the aforementioned differences were statistically significant (P<0.05). In conclusion, all implants exhibited tumor size reduction, growth delay, or apparent tumor clearance. MSCs proved to be effective anti-lymphoma agents; additionally, the combination of soluble TRAIL and IFN-β resulted in the most effective antitumor and life enlarging treatment, showing an additive antitumoral effect compared with individual treatments.

Chemosensitivity analysis and study of gene resistance on tumors and cancer stem cell isolates from patients with colorectal cancer

Colorectal cancer (CRC) is one of the main causes of mortality. Recent studies suggest that cancer stem cells (CSCs) can survive after chemotherapy and promote tumor invasiveness and aggression. According to a higher hierarchy complexity of CSC, different protocols for isolation, expansion, and characterization have been used; however, there are no available resistance biomarkers that allow predicting the clinical response of treatment 5‑fluorouracil (5FU) and oxaliplatin. Therefore, the primary aim of the present study was to analyze the expression of gene resistance on tumors and CSC‑derived isolates from patients CRC. In the present study, adenocarcinomas of the colon and rectum (CRAC) were classified based on an in vitro adenosine triphosphate‑based chemotherapy response assay, as sensitive and resistant and the percentage of CD24 and CD44 markers are evaluated by immunohistochemistry. To isolate resistant colon‑CSC, adenocarcinoma tissues resistant to 5FU and oxaliplatin were evaluated. Finally, all samples were sequenced using a custom assay with chemoresistance‑associated genes to find a candidate gene on resistance colon‑CSC. Results showed that 59% of the CRC tissue analyzed was resistant and had a higher percentage of CD44 and CD24 markers. An association was found in the expression of some genes between the tumor‑resistant tissue and CSC. Overall, isolates of the CSC population CD44+ resistant to 5FU and oxaliplatin demonstrated different expression profiles; however, the present study was able to identify overexpression of the KRT‑18 gene, in most of the isolates. In conclusion, the results of the present study showed overexpression of KRT‑18 in CD44+ cells is associated with chemoresistance to 5FU and oxaliplatin in CRAC.

Inflammatory effect on the gastrointestinal system associated with COVID-19

The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) that causes coronavirus disease-2019 (COVID-19) has provoked a global pandemic, mainly affecting the respiratory tract; however, a percentage of infected individuals can develop gastrointestinal (GI) symptoms. Some studies describe the development of GI symptoms and how they affect the progression of COVID-19. In this review, we summarize the main mechanisms associated with gut damage during infection by SARS-CoV-2 as well as other organs such as the liver and pancreas. Not only are host factors associated with severe COVID-19 but intestinal microbiota dysbiosis is also observed in patients with severe disease.

Behind the Adaptive and Resistance Mechanisms of Cancer Stem Cells to TRAIL

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), also known as Apo-2 ligand (Apo2L), is a member of the TNF cytokine superfamily. TRAIL has been widely studied as a novel strategy for tumor elimination, as cancer cells overexpress TRAIL death receptors, inducing apoptosis and inhibiting blood vessel formation. However, cancer stem cells (CSCs), which are the main culprits responsible for therapy resistance and cancer remission, can easily develop evasion mechanisms for TRAIL apoptosis. By further modifying their properties, they take advantage of this molecule to improve survival and angiogenesis. The molecular mechanisms that CSCs use for TRAIL resistance and angiogenesis development are not well elucidated. Recent research has shown that proteins and transcription factors from the cell cycle, survival, and invasion pathways are involved. This review summarizes the main mechanism of cell adaption by TRAIL to promote response angiogenic or pro-angiogenic intermediates that facilitate TRAIL resistance regulation and cancer progression by CSCs and novel strategies to induce apoptosis.

Colorectal Cancer Stem Cells in the Progression to Liver Metastasis

Colorectal carcinoma (CRC) is a leading cause of cancer mortality. Tumorigenesis is a dynamic process wherein cancer stem cells (CSCs) and their microenvironment promote initiation, progression, and metastasis. Metastatic colonization is an inefficient process that is very complex and is poorly understood; however, in most cases, metastatic disease is not curable, and resistance mechanisms tend to develop against conventional treatments. An understanding of the underlying mechanisms and factors that contribute to the development of metastasis in CRC can aid in the search for specific therapeutic targets for improving standard treatments. In this review, we summarize current knowledge regarding tumor biology and the use of stroma cells as prognostic factors and inflammatory inducers associated with the use of tumor microenvironments as a promoter of cancer metastasis. Moreover, we look into the importance of CSC, pericytes, and circulating tumor cells as mechanisms that lead to liver metastasis, and we also focus on the cellular and molecular pathways that modulate and regulate epithelial–mesenchymal transition. Finally, we discuss a novel therapeutic target that can potentially eliminate CSCs as a CRC treatment.