Adjuvant role of Salvia miltiorrhiza bunge in cancer chemotherapy: A review of its bioactive components, health-promotion effect and mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Chemotherapy is a common cancer treatment strategy. However, its effectiveness is constrained by toxicity and adverse effects. The Lamiaceae herb Salvia miltiorrhiza Bunge has a long history of therapeutic use in the treatment of blood stasis illnesses, which are believed by traditional Chinese medicine to be connected to cancer.

AIM OF THE STUDY

This review summarized the common toxicity of chemotherapy and the potential chemo-adjuvant effect and mechanisms of active ingredients from S. miltiorrhiza, hoping to provide valuable information for the development and application of S. miltiorrhiza resources.

MATERIALS AND METHODS

The literatures were retrieved from PubMed, Web of Science, Baidu Scholar and Google Scholar databases from 2002 to 2022. The inclusion criteria were studies reporting that S. miltiorrhiza or its constituents enhanced the efficiency of chemotherapy drugs or reduced the side effects.

RESULTS

Salvianolic acid A, salvianolic acid B, salvianolic acid C, rosmarinic acid, tanshinone I, tanshinone IIA, cryptotanshinone, dihydrotanshinone I and miltirone are the primary adjuvant chemotherapy components of S. miltiorrhiza. The mechanisms mainly involve inhibiting proliferation, metastasis, and angiogenesis, inducing apoptosis, regulating autophagy and tumor microenvironment. In addition, they also improve chemotherapy drug-induced side effects.

CONCLUSIONS

The bioactive compounds of S. miltiorrhiza are shown to inhibit proliferation, metastasis, and angiogenesis, induce apoptosis and autophagy, regulate immunity and tumor microenvironment when combined with chemotherapy drugs. However, further clinical studies are required to validate the current studies.

CopA3 treatment suppressed multidrug resistivity in HCT-116 cell line by p53-induced degradation of hypoxia-inducible factor 1α

The major reason for multidrug resistance is the failure of chemotherapy in many tumors, including colon cancer. Hypoxia-inducible factor (HIF)-1α is a crucial transcription factor that simulates multiple cellular response to hypoxia. HIF-1α has been known to play a vital role towards tumor resistance; however, its mechanism of action is still not fully elucidated. N this study, we found that HIF-1α remarkably modulated drug resistance-associated proteins upon CopA3 peptide treatment against colon cancer cells. Abnormal rates of tumor growth along with high metastatic potential lacks the susceptibility towards cellular signals is a key characteristic in many tumor types. Moreover, in growing tumors, cells are exposed to insufficient nutrient supply and low oxygen availability. These stress force them to switch into adaptable and aggressive phenotypes. Our study investigated the interaction of HIF-1α and MDR gene association upon CopA3 treatment in the tumor microenvironment. We demonstrate that the multidrug resistance gene is associated with tumor resistance to chemotherapeutics, which upon CopA3 treatment promotes p53 activation and proteasomal degradation of HIF-1α, effecting the angiogenesis response to hypoxia. p53 downregulation augments HIF-1-dependent transcriptional activation of VEGF in response to oxygen deprivation.

Natural products and mitochondrial allies in colorectal cancer therapy

Colorectal cancer (CRC) is a globally prevalent malignancy with a high potential for metastasis. Existing cancer treatments have limitations, including drug resistance and adverse effects. Researchers are striving to develop effective therapies to address these challenges. Impressively, contemporary research has discovered that many natural products derived from foods, plants, insects, and marine invertebrates can suppress the progression, metastasis, and invasion of CRC. In this review, we conducted a comprehensive search of the CNKI, PubMed, Embase, and Web of Science databases from inception to April 2023 to evaluate the efficacy of natural products targeting mitochondria to fight against CRC. Mitochondria are intracellular energy factories involved in cell differentiation, signal transduction, cell cycle regulation, apoptosis, and tumorigenesis. The identified natural products have been classified and summarized based on their mechanisms of action. These findings indicate that natural products can induce apoptosis in colorectal cancer cells by inhibiting the mitochondrial respiratory chain, ROS elevation, disruption of mitochondrial membrane potential, the release of pro-apoptotic factors, modulation of the Bcl-2 protein family to facilitate cytochrome c release, induction of apoptotic vesicle activity by activating the caspase protein family, and selective targeting of mitochondrial division. Furthermore, diverse apoptotic signaling pathways targeting mitochondria, such as the MAPK, p53, STAT3, JNK and AKT pathway, have been triggered by natural products. Natural products such as diosgenin, allopurinol, and clausenidin have demonstrated low toxicity, high efficacy, and multi-targeted properties. Mitochondria-targeting natural products have great potential for overcoming the challenges of CRC therapy.

Monitoring Metabolic Changes in Response to Chemotherapies in Cancer with Raman Spectroscopy and Metabolomics

Resistance to clinical therapies remains a major barrier in cancer management. There is a critical need for rapid and highly sensitive diagnostic tools that enable early prediction of treatment response to allow accurate clinical decisions. Here, Raman spectroscopy was employed to monitor changes in key metabolites as early predictors of response in KRAS-mutant colorectal cancer (CRC) cells, HCT116, treated with chemotherapies. We show at the single cell level that HCT116 is resistant to cetuximab (CTX), the first-line treatment in CRC, but this resistance can be overcome with pre-sensitization of cells with oxaliplatin (OX). In combination treatment of CTX + OX, sequential delivery of OX followed by CTX rather than simultaneous administration of drugs was observed to be critical for effective therapy. Our results demonstrated that metabolic changes are well aligned to cellular mechanical changes where Young's modulus decreased after effective treatment, indicating that both changes in mechanical properties and metabolism in cells are likely responsible for cancer proliferation. Raman findings were verified with mass spectrometry (MS) metabolomics, and both platforms showed changes in lipids, nucleic acids, and amino acids as predictors of resistance/response. Finally, key metabolic pathways enriched were identified when cells are resistant to CTX but downregulated with effective treatment. This study highlights that drug-induced metabolic changes both at the single cell level (Raman) and ensemble level (MS) have the potential to identify mechanisms of response to clinical cancer therapies.

Autophagy/ferroptosis in colorectal cancer: Carcinogenic view and nanoparticle-mediated cell death regulation

The cell death mechanisms have a long history of being evaluated in diseases and pathological events. The ability of triggering cell death is considered to be a promising strategy in cancer therapy, but some mechanisms have dual functions in cancer, requiring more elucidation of underlying factors. Colorectal cancer (CRC) is a disease and malignant condition of colon and rectal that causes high mortality and morbidity. The autophagy targeting in CRC is therapeutic importance and this cell death mechanism can interact with apoptosis in inhibiting or increasing apoptosis. Autophagy has interaction with ferroptosis as another cell death pathway in CRC and can accelerate ferroptosis in suppressing growth and invasion. The dysregulation of autophagy affects the drug resistance in CRC and pro-survival autophagy can induce drug resistance. Therefore, inhibition of protective autophagy enhances chemosensitivity in CRC cells. Moreover, autophagy displays interaction with metastasis and EMT as a potent regulator of invasion in CRC cells. The same is true for ferroptosis, but the difference is that function of ferroptosis is determined and it can reduce viability. The lack of ferroptosis can cause development of chemoresistance in CRC cells and this cell death mechanism is regulated by various pathways and mechanisms that autophagy is among them. Therefore, current review paper provides a state-of-art analysis of autophagy, ferroptosis and their crosstalk in CRC. The nanoparticle-mediated regulation of cell death mechanisms in CRC causes changes in progression. The stimulation of ferroptosis and control of autophagy (induction or inhibition) by nanoparticles can impair CRC progression. The engineering part of nanoparticle synthesis to control autophagy and ferroptosis in CRC still requires more attention.

The role of redox-mediated lysosomal dysfunction and therapeutic strategies

Redox homeostasis refers to the dynamic equilibrium between oxidant and reducing agent in the body which plays a crucial role in maintaining normal physiological activities of the body. The imbalance of redox homeostasis can lead to the development of various human diseases. Lysosomes regulate the degradation of cellular proteins and play an important role in influencing cell function and fate, and lysosomal dysfunction is closely associated with the development of various diseases. In addition, several studies have shown that redox homeostasis plays a direct or indirect role in regulating lysosomes. Therefore, this paper systematically reviews the role and mechanisms of redox homeostasis in the regulation of lysosomal function. Therapeutic strategies based on the regulation of redox exerted to disrupt or restore lysosomal function are further discussed. Uncovering the role of redox in the regulation of lysosomes helps to point new directions for the treatment of many human diseases.

Tumor-associated macrophages confer colorectal cancer 5-fluorouracil resistance by promoting MRP1 membrane translocation via an intercellular CXCL17/CXCL22-CCR4-ATF6-GRP78 axis

Chemotherapy represents a major type of clinical treatment against colorectal cancer (CRC). Aberrant drug efflux mediated by transporters acts as a key approach for tumor cells to acquire chemotherapy resistance. Increasing evidence implies that tumor-associated macrophages (TAMs) play a pivotal role in both tumorigenesis and drug resistance. Nevertheless, the specific mechanism through which TAMs regulate drug efflux remains elusive. Here, we discovered that TAMs endow CRC cells with resistance to 5-fluorouracil (5-FU) treatment via a cell-cell interaction-mediated MRP1-dependent drug efflux process. Mechanistically, TAM-secreted C-C motif chemokine ligand 17 (CCL17) and CCL22, via membrane receptor CCR4, activated the PI3K/AKT pathway in CRC tumor cells. Specifically, phosphorylation of AKT inactivated IP3R and induced calcium aggregation in the ER, resulting in the activation of ATF6 and upregulation of GRP78. Accordingly, excessive GRP78 can interact with MRP1 and promote its translocation to the cell membrane, causing TAM-induced 5-FU efflux. Taken together, our results demonstrated that TAMs promote CRC chemotherapy resistance via elevating the expression of GRP78 to promote the membrane translocation of MRP1 and drug efflux, providing direct proof for TAM-induced drug resistance.

Potential antitumor activity of garlic against colorectal cancer: focus on the molecular mechanisms of action

PURPOSE

The aim of this review is to highlight the potential of garlic phytoconstituents as antitumor agents in colorectal cancer management based on their molecular mechanisms of action, while asking if their consumption, as part of the human diet, might contribute to the prevention of colorectal cancer.

METHODS

To gather information on appropriate in vitro, in vivo and human observational studies on this topic, the keywords "Allium sativum", "garlic", "colorectal cancer", "antitumor effect", "in vitro", "in vivo", "garlic consumption" and "colorectal cancer risk" were searched in different combinations in the international databases ScienceDirect, PubMed and Google Scholar. After duplicate and reviews removal, 61 research articles and meta-analyses published between 2000 and 2022 in peer-reviewed journals were found and included in this review.

RESULTS

Garlic (Allium sativum) proves to be a rich source of compounds with antitumor potential. Garlic-derived extracts and several of its individual constituents, especially organosulfur compounds such as allicin, diallyl sulfide, diallyl disulfide, diallyl trisulfide, diallyl tetrasulfide, allylmethylsulfide, S-allylmercaptocysteine, Z-ajoene, thiacremonone and Se-methyl-L-selenocysteine were found to possess cytotoxic, cytostatic, antiangiogenic and antimetastatic activities in different in vitro and in vivo models of colorectal cancer. The molecular mechanisms for their antitumor effects are associated with the modulation of several well-known signaling pathways involved in cell cycle progression, especially G1-S and G2-M transitions, as well as both the intrinsic and extrinsic apoptotic pathways. However, even though in various animal models some of these compounds have chemopreventive effects, based on different human observational studies, a diet rich in garlic is not consistently associated with a lower risk of developing colorectal cancer.

CONCLUSION

Independent of the impact of garlic consumption on colorectal cancer initiation and promotion in humans, its constituents might be good candidates for future conventional and/or complementary therapies, based on their diverse mechanisms of action.

CD44 mediated colon cancer targeting mutlifaceted lignin nanoparticles: Synthesis, in vitro characterization and in vivo efficacy studies

Hyaluronic acid (HA) coated irinotecan loaded lignin nanoparticles (HDLNPs) were synthesized using ionic interaction method. Optimized nanoparticles were characterized for their active chemotherapeutic targeting potential to CD44 receptors overly-expressed on cancer cells. Blood component interaction studies supported hemocompatible nature of HDLNPs and also demonstrated their sustained plasma residence property. Cell anti-proliferation and mitochondrial depolarization studies on HT-29 cells suggest significantly (p < 0.01) improved chemotherapeutic efficacy of HDLNPs. In vitro cell based studies showed that nanoparticles have retained antioxidant activity of lignin that can prevent cancer relapse. In vivo biodistribution studies in tumor-bearing Balb/c mice confirmed improved drug localization in tumor site for longer duration. Tumor regression and histopathological studies indicated the efficacy ofligand-assisted targeting chemotherapy over the conventional therapy. Hematological and biochemical estimation suggested that irinotecan-associated myelosuppression, liver steatosis and rare kidney failure can be avoided by its encapsulation in HA-coated lignin nanoparticles. HDLNPs were found to be stable over a period of 12 months.

GPX2 acts as an oncogene and cudraflavone C has an anti-tumor effect by suppressing GPX2-dependent Wnt/β-catenin pathway in colorectal cancer cells

Colorectal carcinoma (CRC) is a common cancer associated with poor prognosis, and cudraflavone C (Cud C) is a natural flavonol with reported anti-CRC capacity. However, the precise mechanisms underlying the anti-CRC effect require further demonstration. The aim of present study was to evaluate the impact of Cud C on the cell viability and apoptosis of CRC cells and to determine the underlying mechanisms. The Human Protein Atlas (THPA) and Gene Expression Profiling Interactive Analysis (GEPIA) databases were used to analyze the expression status of glutathione peroxidase 2 (GPX2) in CRC. Cell viability was examined using cell counting kit-8 (CCK-8) assay. Flow cytometry was utilized to evaluate apoptosis. The levels of gene transcription and protein expression of GPX2, caspase-3, cleaved caspase-3), β-catenin, and c-Myc were determined by RT-qPCR and Western blotting. Our results showed that GPX2 was overexpressed in CRC as compared to normal tissue and the extent of GPX2 overexpression is greatest in CRC when compared with other cancers according to GEPIA and THPA databases. GPX2 knockdown significantly suppressed the cell viability, induced apoptosis of CRC cell lines, and restrained the activity of Wnt/β-catenin pathway. Cud C treatment decreased cell viability, induced apoptosis in CRC cell lines, and diminished the expression level of GPX2-dependent activation of Wnt/β-catenin pathway, while such effects can be abolished by GPX2 overexpression. In conclusion, Cud C suppressed GPX2-dependent Wnt/β-catenin pathway to exert anti-CRC function.

Ginseng mediates its anticancer activity by inhibiting the expression of DNMTs and reactivating methylation-silenced genes in colorectal cancer

Developing safe and effective therapeutic modalities remains a critical challenge for improving the prognosis of patients with colorectal cancer (CRC). In this regard, targeting epigenetic regulation in cancers has recently emerged as a promising therapeutic approach. Since several natural compounds have recently been shown to be important epigenetic modulators, we hypothesized that Ginseng might exert its anticancer activity by regulating DNA methylation alterations in CRC. In this study, a series of cell culture studies were conducted, followed by their interrogation in patient-derived 3D organoid models to evaluate Ginseng's anticancer activity in CRC. Genome-wide methylation alterations were interrogated by undertaking MethylationEpic BeadChip microarrays. First, 50% inhibitory concentrations (IC50) were determined by cell viability assays, and subsequent Ginseng treatment demonstrated a significant anticancer effect on clonogenicity and cellular migration in CRC cells. Treatment with Ginseng potentiated cellular apoptosis through regulation of apoptosis-related genes in CRC cells. Furthermore, Ginseng treatment downregulated the expression of DNA methyltransferases (DNMTs) and decreased the global DNA methylation levels in CRC cells. The genome-wide methylation profiling identified Ginseng-induced hypomethylation of transcriptionally silenced tumor suppressor genes. Finally, cell culture-based findings were successfully validated in patient-derived 3D organoids. In conclusion, we demonstrate that Ginseng exerts its antitumorigenic potential by regulating cellular apoptosis via the downregulation of DNMTs and reversing the methylation status of transcriptionally silenced genes in CRC.

No Associations between Dairy Intake and Markers of Gastrointestinal Inflammation in Healthy Adult Cohort

Dairy products are a good source of essential nutrients and past reviews have shown associations of dairy consumption with decreased systemic inflammation. Links between dairy intake and gastrointestinal (GI) inflammation are under-investigated. Therefore, we examined associations between reported dairy intake and markers of GI inflammation in healthy adults in a cross-sectional observational study, hypothesizing a negative association with yogurt intake, suggesting a protective effect, and no associations with total dairy, fluid milk, and cheese intake. Participants completed 24-h dietary recalls and a food frequency questionnaire (FFQ) to assess recent and habitual intake, respectively. Those who also provided a stool sample (n = 295), and plasma sample (n = 348) were included in analysis. Inflammation markers from stool, including calprotectin, neopterin, and myeloperoxidase, were measured along with LPS-binding protein (LBP) from plasma. Regression models tested associations between dairy intake variables and inflammation markers with covariates: age, sex, and body mass index (BMI). As yogurt is episodically consumed, we examined differences in inflammation levels between consumers (>0 cup equivalents/day reported in recalls) and non-consumers. We found no significant associations between dairy intake and markers of GI inflammation. In this cohort of healthy adults, dairy intake was not associated with GI inflammation.

Isoliensinine augments the therapeutic potential of paclitaxel in multidrug-resistant colon cancer stem cells and induced mitochondria-mediated cell death

Previously we have reported the isoliensinine (ISO) potentates the therapeutic potential of cisplatin in cisplatin resistant colorectal cancer stem cells. The present study evaluates the chemo-sensitizing potential of the combinatorial regimen of ISO and Paclitaxcel (PTX) on multidrug-resistant (MDR)-HCT-15 cells to reduce the dose requirement of both ISO and PTX. The results of the present study suggest that treatment with the combinatorial regimen of ISO and PTX enhanced the cytotoxic effect with resultant increase in apoptosis in MDR-HCT-15 cells as evident from the altered cellular morphology, G2/M cell cycle arrest, propidium iodide uptake, Annexin V, increased intracellular Ca2+ accumulation, decreased mitochondrial membrane potential, diminished ATP production, PARP-1 cleavage, altered expression of ERK1/2, and apoptotic proteins. Treatment with combinatorial regimen of ISO and PTX also modulated the expression of the transcription factors SOX2, OCT4 which determine the stemness of cancer cells. Thus, results of the present study suggest that ISO and PTX combination regimen induces apoptosis in MDR-HCT-15 in a synergistic manner.

Resveratrol as sensitizer in colorectal cancer plasticity

Despite tremendous medical treatment successes, colorectal cancer (CRC) remains a leading cause of cancer deaths worldwide. Chemotherapy as monotherapy can lead to significant side effects and chemoresistance that can be linked to several resistance-activating biological processes, including an increase in inflammation, cellular plasticity, multidrug resistance (MDR), inhibition of the sentinel gene p53, and apoptosis. As a consequence, tumor cells can escape the effectiveness of chemotherapeutic agents. This underscores the need for cross-target therapeutic approaches that are not only pharmacologically safe but also modulate multiple potent signaling pathways and sensitize cancer cells to overcome resistance to standard drugs. In recent years, scientists have been searching for natural compounds that can be used as chemosensitizers in addition to conventional medications for the synergistic treatment of CRC. Resveratrol, a natural polyphenolic phytoalexin found in various fruits and vegetables such as peanuts, berries, and red grapes, is one of the most effective natural chemopreventive agents. Abundant in vitro and in vivo studies have shown that resveratrol, in interaction with standard drugs, is an effective chemosensitizer for CRC cells to chemotherapeutic agents and thus prevents drug resistance by modulating multiple pathways, including transcription factors, epithelial-to-mesenchymal transition-plasticity, proliferation, metastasis, angiogenesis, cell cycle, and apoptosis. The ability of resveratrol to modify multiple subcellular pathways that may suppress cancer cell plasticity and reversal of chemoresistance are critical parameters for understanding its anti-cancer effects. In this review, we focus on the chemosensitizing properties of resveratrol in CRC and, thus, its potential importance as an additive to ongoing treatments.

Characterization of 3D heterocellular spheroids of pancreatic ductal adenocarcinoma for the study of cell interactions in the tumor immune microenvironment

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies nowadays. The available chemo- and immunotherapies are often ineffective in treating PDAC due to its immunosuppressive and highly desmoplastic tumor immune microenvironment (TIME), which is hardly reproduced in the existing preclinical models. The PDAC TIME results from a peculiar spatial organization between different cell types. For this reason, developing new human models recapitulating the tissue organization and cell heterogeneity of PDAC is highly desirable. We developed human 3D heterocellular tumor spheroids of PDAC formed by cancer cells, endothelial cells, pancreatic stellate cells (PSC), and monocytes. As a control, we formed spheroids using immortalized epithelial pancreatic ductal cells (non-cancerous spheroids) with cellular heterogeneity similar to the tumor spheroids. Normal spheroids containing endothelial cells formed a complex 3D endothelial network significantly compromised in tumor spheroids. Monocyte/macrophages within the 4-culture tumor spheroids were characterized by a higher expression of CD163, CD206, PD-L1, and CD40 than those in the non-cancerous spheroids suggesting their differentiation towards an immunosuppressive phenotype. The heterocellular tumor spheroids presented a hypoxic core populated with PSC and monocytes/macrophages. The 4-culture tumor spheroids were characterized by spatial proximity of PSC and monocytes to the endothelial cells and a cytokine signature with increased concentrations of CXCL10, CCL2, and IL-6, which have been observed in PDAC patients and associated with poor survival. Further, 4-culture tumor spheroids decreased the concentrations of T-cell chemoattracting cytokines, i.e., CCL4, CCL5, and CXCL9, when compared with the non-cancerous spheroids, revealing a critical immunosuppressive feature of the different types of cells forming the tumor spheroids. Our results showed that the 4-culture tumor spheroids better resembled some critical features of patients' PDAC TIME than monoculture tumor spheroids. Using the proposed human 3D spheroid model for therapy testing at the preclinical stage may reveal pitfalls of chemo- and immuno-therapies to help the development of better anti-tumor therapies.

Assessing the Potential Biological Activities of Postbiotics Derived from Saccharomyces cerevisiae: An In Vitro Study

A new biotherapeutic strategy involves the use of microbial bioactive substances (postbiotics) that exhibit optimum compatibility and intimate contact with the immune system of the host. This study was aimed at investigating the potential biological activities of postbiotics derived from Saccharomyces cerevisiae (PTCC 5269) (PSC) under in vitro circumstances. Based on the outcomes, the synthesized PSC possessing a high level of phenolic (102.46 ± 0.25 mg GAE/g) and flavonoid (19.87 ± 75.32 mg QE/g) content demonstrated significant radical scavenging activity (87.34 ± 0.56%); antibacterial action towards Listeria monocytogenes, Streptococcus mutans, Salmonella typhi, and Escherichia coli (in order of effectiveness) in both in vitro and food models (whole milk and ground meat); probiotics' growth-promoting activity in the fermentation medium; α-glucosidase enzyme-inhibiting and cholesterol-lowering properties in a concentration- and pH-dependent manner; reduction in the cell viability (with the significant IC₅₀ values of 34.27 and 23.58 μg/mL after 24 and 48 h, respectively); suppressed the initial (G0/G1) phase of the cell's division; induced apoptosis; and increased the expression of PTEN gene, while the IkB, RelA, and Bcl-XL genes indicated diminished expression in treated SW480 cancer cells. These multiple health-promoting functions of PSC can be extended to medical, biomedical, and food scopes, as novel biotherapeutic approaches, in order to design efficient and optimized functional food formulations or/and supplementary medications to use as adjuvant agents for preventing or/and treating chronic/acute disorders.

Identification of Moesin (MSN) as a Potential Therapeutic Target for Colorectal Cancer via the β-Catenin-RUNX2 Axis

CRC is the second leading cause of cancer-related death. The complex mechanisms of metastatic CRC limit available therapeutic choice. Thus, identifying new CRC therapeutic targets is essential. Moesin (MSN), a member of the ezrin-radixin-moesin family, connects the cell membrane to the actin-based cytoskeleton and regulates cell morphology. We investigated the role of MSN in the progression of CRC. GENT2 and oncomine were used to study MSN expression and CRC patient outcomes. MSN-specific shRNAs or MSN-overexpressed plasmid were used to establish MSN-KD and MSN overexpressed cell lines, respectively. SRB, migration, wound healing, and flow cytometry were used to test cell survival and migration. Propidium iodide and annexin V stain were used to analyze the cell cycle and apoptosis. MSN expression was found to be higher in CRC tissues than in normal tissues. Higher MSN expression is associated with poor overall survival, disease-free survival, and relapse-free survival rates in CRC patients. MSN silencing inhibits cell proliferation, adhesion, migration, and invasion in vitro, whereas MSN overexpression accelerates cell proliferation, adhesion, migration, and invasion. RNA sequencing was used to investigate differentially expressed genes, and RUNX2 was discovered as a possible downstream target for MSN. In CRC patients, RUNX2 expression was significantly correlated with MSN expression. We also found that MSN silencing decreased cytoplasmic and nuclear β-catenin levels. Additionally, pharmacological inhibition of β-catenin in MSN-overexpressed cells led to a reduction of RUNX2, and activating β-catenin signaling by inhibiting GSK3β rescued the RUNX2 downregulation in MSN-KD cells. This confirms that MSN regulates RUNX2 expression via activation of β-catenin signaling. Finally, our result further determined that RUNX2 silencing reduced the ability of MSN overexpression cells to proliferate and migrate. MSN accelerated CRC progression via the β-catenin-RUNX2 axis. As a result, MSN holds the potential to become a new target for CRC treatment.

Ibrutinib amorphous solid dispersions with enhanced dissolution at colonic pH for the localized treatment of colorectal cancer

Colorectal cancer (CRC) is the second most leading cause of cancer-related deaths worldwide. Ibrutinib (IBR), the first in class bruton tyrosine kinase (BTK) inhibitor has promising anticancer activity. In this study, we aimed to develop a hot melt extrusion based amorphous solid dispersions (ASD) of IBR with enhanced dissolution at colonic pH and assess the anticancer activity against colon cancer cell lines. Since colonic pH is higher in CRC patients compared to healthy individuals, Eudragit® FS100 was used as pH dependent polymeric matrix for colon enabled release of IBR. Poloxamer 407, TPGS and poly(2-ethyl-2-oxazoline) were screened as plasticizer and solubilizer to improve the processability and solubility. Solid state characterization and filament appearance confirmed that IBR was molecularly dispersed within FS100+TPGS matrix. In-vitro drug release of ASD showed >96% drug release within 6 h at colonic pH with no precipitation for 12 h. Contrary, crystalline IBR showed negligible release. ASD with TPGS showed significantly higher anticancer activity in 2D and multicellular 3D spheroids of colon carcinoma cell lines (HT-29 and HT-116). The outcomes of this research suggested that ASD with a pH dependent polymer is a promising strategy to improve solubility and an effective approach in colorectal cancer targeting.

Multidimensional controllable fabrication of tumor spheroids based on a microfluidic device

Multicellular tumor spheroids (MCTSs) are in vitro solid tumor models with physiological relevance. To achieve robust process control, a MCTS fabrication method that combines cell membrane engineering and droplet microfluidic techniques is designed. The fluidic control and the chemical interactions between biotin and streptavidin enable artificial cell aggregation to be accomplished in seconds. Then, spheroids with a uniform size are fabricated within alginate microcapsules. Microfluidic mixing-based cell aggregation regulates the cell aggregate size and the spheroid composition, and the microcapsules regulate the size of spheroids from 120 to 180 μm. The method shows applicability for various cancer cell lines, including HCT116, HepG2, and A549. In addition, composite colon cancer spheroids consisting of HCT116 and NIH3T3 with predetermined cell ratios and uniform distributions are produced. The generated MCTSs are assessed using the ELISA and UPLC-MS/MS techniques. The release of vascular endothelial growth factor (VEGF) and the 5-fluorouracil (5-FU) resistance differ in the monotypic and cocultured colon cancer models. Our method provides a robust way to produce consistent and customized MCTSs in cancer research and drug screening.

Evolution of Resistance to Irinotecan in Cancer Cells Involves Generation of Topoisomerase-Guided Mutations in Non-Coding Genome That Reduce the Chances of DNA Breaks

Resistance to chemotherapy is a leading cause of treatment failure. Drug resistance mechanisms involve mutations in specific proteins or changes in their expression levels. It is commonly understood that resistance mutations happen randomly prior to treatment and are selected during the treatment. However, the selection of drug-resistant mutants in culture could be achieved by multiple drug exposures of cloned genetically identical cells and thus cannot result from the selection of pre-existent mutations. Accordingly, adaptation must involve the generation of mutations de novo upon drug treatment. Here we explored the origin of resistance mutations to a widely used Top1 inhibitor, irinotecan, which triggers DNA breaks, causing cytotoxicity. The resistance mechanism involved the gradual accumulation of recurrent mutations in non-coding regions of DNA at Top1-cleavage sites. Surprisingly, cancer cells had a higher number of such sites than the reference genome, which may define their increased sensitivity to irinotecan. Homologous recombination repairs of DNA double-strand breaks at these sites following initial drug exposures gradually reverted cleavage-sensitive "cancer" sequences back to cleavage-resistant "normal" sequences. These mutations reduced the generation of DNA breaks upon subsequent exposures, thus gradually increasing drug resistance. Together, large target sizes for mutations and their Top1-guided generation lead to their gradual and rapid accumulation, synergistically accelerating the development of resistance.

FOSL1 transcriptionally regulates PHLDA2 to promote 5-FU resistance in colon cancer cells

BACKGROUND

Tumor drug resistance is a leading cause of tumor treatment failure. To date, the association between FOS-Like antigen-1 (FOSL1) and chemotherapy sensitivity in colon cancer is unclear. The present study investigated the molecular mechanism of FOSL1 regulating 5-Fluorouracil (5-FU) resistance in colon cancer.

METHODS

FOSL1 expression in colon cancer was analyzed by bioinformatics methods, and its downstream regulatory factors were predicted. Pearson correlation analyzed the expression of FOSL1 and downstream regulatory gene. Meanwhile, the expression of FOSL1 and its downstream factor Pleckstrin Homology-Like Domain Family A Member 2 (PHLDA2) in colon cancer cell lines was measured by qRT-PCR and western blot. The regulatory relationship between FOSL1 and PHLDA2 was verified by chromatin immunoprecipitation (ChIP) assay and dual-luciferase reporter assay. The effects of the FOSL1/PHLDA2 axis on the resistance in colon cancer cells to 5-FU were analyzed by cell experiments.

RESULTS

FOSL1 expression was evidently up-regulated in colon cancer and 5-FU resistant cells. FOSL1 was positively correlated with PHLDA2 in colon cancer. In vitro cell assays showed that low expression of FOSL1 significantly enhanced 5-FU sensitivity in colon cancer cells, significantly suppressed the proliferation of cancer cells, and induced apoptosis. Overexpression of FOSL1 presented the opposite regulatory trend. Mechanistically, FOSL1 activated PHLDA2 and up-regulated its expression. Moreover, by activating glycolysis, PHLDA2 promoted 5-Fu resistance and cell proliferation, and reduced cell apoptosis in colon cancer.

CONCLUSION

Down-regulated FOSL1 expression could enhance the 5-FU sensitivity of colon cancer cells, and FOSL1/PHLDA2 axis may be an effective target for overcoming chemotherapy resistance in colon cancer.