MKK3 sustains cell proliferation and survival through p38DELTA MAPK activation in colorectal cancer

CircSEC24B activates autophagy and induces chemoresistance of colorectal cancer via OTUB1-mediated deubiquitination of SRPX2

Circular RNAs (circRNAs) are a type of regulatory RNA that feature covalently closed single-stranded loops. Evidence suggested that circRNAs play important roles in the progression and development of various cancers. However, the impact of circRNA on autophagy-mediated progression of colorectal cancer (CRC) remains unclear. The objective of this project was to investigate the influence of circSEC24B on autophagy and its underlying mechanisms in CRC. To validate the presence and circular structure of circSEC24B in CRC cells and tissues, PCR and Sanger sequencing techniques were employed. Drug resistance and invasive phenotype of CRC cells were evaluated using CCK8, transwell, and Edu assays. Gain- and loss-of-function experiments were conducted to assess the effects of circSEC24B and its protein partner on the growth, invasion, and metastasis of CRC cells in vitro and in vivo. Interactions between circSEC24B, OTUB1, and SRPX2 were analyzed through immunofluorescence, RNA-pulldown, and RIP assays. Mass spectrometry analysis was used to identify potential binding proteins of circRNA in CRC cells. Vectors were constructed to investigate the specific structural domain of the deubiquitinating enzyme OTUB1 that binds to circSEC24B. Results showed that circSEC24B expression was increased in CRC tissues and cell lines, and it enhanced CRC cell proliferation and autophagy levels. Mechanistically, circSEC24B promoted CRC cell proliferation by regulating the protein stability of SRPX2. Specifically, circSEC24B acted as a scaffold, facilitating the binding of OTUB1 to SRPX2 and thereby enhancing its protein stability. Additionally, evidence suggested that OTUB1 regulated SRPX2 expression through an acetylation-dependent mechanism. In conclusion, this study demonstrated that circSEC24B activated autophagy and induced chemoresistance in CRC by promoting the deubiquitination of SRPX2, mediated by the deubiquitinating enzyme OTUB1.

Repurposed AT9283 triggers anti-tumoral effects by targeting MKK3 oncogenic functions in Colorectal Cancer

BACKGROUND

Colorectal cancer (CRC) is the third most common type of cancer and the second leading cause of cancer-related deaths worldwide, with a survival rate near to 10% when diagnosed at an advanced stage. Hence, the identification of new molecular targets to design more selective and efficient therapies is urgently required. The Mitogen activated protein kinase kinase 3 (MKK3) is a dual-specificity threonine/tyrosine protein kinase that, activated in response to cellular stress and inflammatory stimuli, regulates a plethora of biological processes. Previous studies revealed novel MKK3 roles in supporting tumor malignancy, as its depletion induces autophagy and cell death in cancer lines of different tumor types, including CRC. Therefore, MKK3 may represent an interesting new therapeutic target in advanced CRC, however selective MKK3 inhibitors are currently not available.

METHODS

The study involved transcriptomic based drug repurposing approach and confirmatory assays with CRC lines, primary colonocytes and a subset of CRC patient-derived organoids (PDO). Investigations in vitro and in vivo were addressed.

RESULTS

The repurposing approach identified the multitargeted kinase inhibitor AT9283 as a putative compound with MKK3 depletion-mimicking activities. Indeed, AT9283 drops phospho- and total-MKK3 protein levels in tested CRC models. Likely the MKK3 silencing, AT9283 treatment: i) inhibited cell proliferation promoting autophagy and cell death in tested CRC lines and PDOs; ii) resulted well-tolerated by CCD-18Co colonocytes; iii) reduced cancer cell motility inhibiting CRC cell migration and invasion; iv) inhibited COLO205 xenograft tumor growth. Mechanistically, AT9283 abrogated MKK3 protein levels mainly through the inhibition of aurora kinase A (AURKA), impacting on MKK3/AURKA protein-protein interaction and protein stability therefore uncovering the relevance of MKK3/AURKA crosstalk in sustaining CRC malignancy in vitro and in vivo.

CONCLUSION

Overall, we demonstrated that the anti-tumoral effects triggered by AT9283 treatment recapitulated the MKK3 depletion effects in all tested CRC models in vitro and in vivo, suggesting that AT9283 is a repurposed drug. According to its good tolerance when tested with primary colonocytes (CCD-18CO), AT9283 is a promising drug for the development of novel therapeutic strategies to target MKK3 oncogenic functions in late-stage and metastatic CRC patients.

Discovery of pyrazolo[3,4-d]pyrimidines as novel mitogen-activated protein kinase kinase 3 (MKK3) inhibitors

The dual-specificity protein kinase MKK3 has been implicated in tumor cell proliferation and survival, yet its precise role in cancer remains inconclusive. A critical step in elucidating the kinase's involvement in disease biology is the identification of potent, cell-permeable kinase inhibitors. Presently, MKK3 lacks a dedicated tool compound for these purposes, along with validated methods for the facile screening, identification, and optimization of inhibitors. In this study, we have developed a TR-FRET-based enzymatic assay for the detection of MKK3 activity in vitro and a BRET-based assay to assess ligand binding to this enzyme within intact human cells. These assays were instrumental in identifying hit compounds against MKK3 that share a common chemical scaffold, sourced from a library of bioactive kinase inhibitors. Initial hits were subsequently expanded through the synthesis of novel analogs. The resulting structure-activity relationship (SAR) was rationalized using molecular dynamics simulations against a homology model of MKK3. We expect our findings to expedite the development of novel, potent, selective, and bioactive inhibitors, thus facilitating investigations into MKK3's role in various cancers.

Natural products targeting the MAPK-signaling pathway in cancer: overview

PURPOSE

This article summarizes natural products that target the MAPK-signaling pathway in cancer therapy. The classification, chemical structures, and anti-cancer mechanisms of these natural products are elucidated, and comprehensive information is provided on their potential use in cancer therapy.

METHODS

Using the PubMed database, we searched for keywords, including "tumor", "cancer", "natural product", "phytochemistry", "plant chemical components", and "MAPK-signaling pathway". We also screened for compounds with well-defined structures that targeting the MAPK-signaling pathway and have anti-cancer effects. We used Kingdraw software and Adobe Photoshop software to draw the chemical compound structural diagrams.

RESULTS

A total of 131 papers were searched, from which 85 compounds with well-defined structures were selected. These compounds have clear mechanisms for targeting cancer treatment and are mainly related to the MAPK-signaling pathway. Examples include eupatilin, carvacrol, oridonin, sophoridine, diosgenin, and juglone. These chemical components are classified as flavonoids, phenols, terpenoids, alkaloids, steroidal saponins, and quinones.

CONCLUSIONS

Certain MAPK pathway inhibitors have been used for clinical treatment. However, the clinical feedback has not been promising because of genomic instability, drug resistance, and side effects. Natural products have few side effects, good medicinal efficacy, a wide range of sources, individual heterogeneity of biological activity, and are capable of treating disease from multiple targets. These characteristics make natural products promising drugs for cancer treatment.

Activated MKK3/MYC crosstalk impairs dabrafenib response in BRAFV600E colorectal cancer leading to resistance

Colorectal cancer (CRC) patients with BRAF mutations develop resistance to BRAF inhibitors at a very early stage. Understanding the molecular mechanisms involved in BRAF inhibitor resistance is critical for the development of novel therapeutic opportunities for this subtype of CRC patients. CRC cells bearing BRAF mutations are mostly sensitive to the abrogation of Mitogen-Activated Protein Kinase Kinase 3 (MKK3), a specific activator of p38MAPKs signaling, suggesting that BRAF alterations might addict CRC cells to the MKK3/p38MAPK signaling. Interestingly, publicly available gene expression profiling data show significantly higher MKK3 transcript levels in CRC lines with acquired resistance to BRAF inhibitors. Herein, we investigated the roles of MKK3 in the response to BRAF targeting (dabrafenib) with COLO205 and HT29 BRAFV600E CRC lines and derived dabrafenib-resistant (DABR) sublines. Dabrafenib treatments reduce MKK3 activation by inducing autophagy in parental but not DABR cells. The MKK3 knockdown induces cell death in DABR cells, whereas ectopic MKK3 expression reduces dabrafenib sensitivity in parental cells. Mechanistically, activated MKK3 interacts and co-localizes with c-Myc oncoprotein (MYC), sustaining MYC protein stability and thus preventing the dabrafenib induced effects in CRC DABR cells both in vitro and in vivo. Overall, we identify a novel molecular mechanism beyond the dabrafenib resistance, shedding light on an uncovered vulnerability for the development of novel therapeutic opportunities in BRAFV600E CRC.

MicroRNAs and MAPKs: Evidence of These Molecular Interactions in Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disorder known to be the leading cause of dementia worldwide. Many microRNAs (miRNAs) were found deregulated in the brain or blood of AD patients, suggesting a possible key role in different stages of neurodegeneration. In particular, mitogen-activated protein kinases (MAPK) signaling can be impaired by miRNA dysregulation during AD. Indeed, the aberrant MAPK pathway may facilitate the development of amyloid-beta (Aβ) and Tau pathology, oxidative stress, neuroinflammation, and brain cell death. The aim of this review was to describe the molecular interactions between miRNAs and MAPKs during AD pathogenesis by selecting evidence from experimental AD models. Publications ranging from 2010 to 2023 were considered, based on PubMed and Web of Science databases. According to obtained data, several miRNA deregulations may regulate MAPK signaling in different stages of AD and conversely. Moreover, overexpressing or silencing miRNAs involved in MAPK regulation was seen to improve cognitive deficits in AD animal models. In particular, miR-132 is of particular interest due to its neuroprotective functions by inhibiting Aβ and Tau depositions, as well as oxidative stress, through ERK/MAPK1 signaling modulation. However, further investigations are required to confirm and implement these promising results.

Functional Roles of JNK and p38 MAPK Signaling in Nasopharyngeal Carcinoma

c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) family members integrate signals that affect proliferation, differentiation, survival, and migration in a cell context- and cell type-specific way. JNK and p38 MAPK activities are found upregulated in nasopharyngeal carcinoma (NPC). Studies have shown that activation of JNK and p38 MAPK signaling can promote NPC oncogenesis by mechanisms within the cancer cells and interactions with the tumor microenvironment. They regulate multiple transcription activities and contribute to tumor-promoting processes, ranging from cell proliferation to apoptosis, inflammation, metastasis, and angiogenesis. Current literature suggests that JNK and p38 MAPK activation may exert pro-tumorigenic functions in NPC, though the underlying mechanisms are not well documented and have yet to be fully explored. Here, we aim to provide a narrative review of JNK and p38 MAPK pathways in human cancers with a primary focus on NPC. We also discuss the potential therapeutic agents that could be used to target JNK and p38 MAPK signaling in NPC, along with perspectives for future works. We aim to inspire future studies further delineating JNK and p38 MAPK signaling in NPC oncogenesis which might offer important insights for better strategies in diagnosis, prognosis, and treatment decision-making in NPC patients.

Dissection of the MKK3 Functions in Human Cancer: A Double-Edged Sword?

The role played by MKK3 in human cancer is controversial. MKK3 is an evolutionarily conserved protein kinase that activates in response to a variety of stimuli. Phosphorylates, specifically the p38MAPK family proteins, contribute to the regulation of a plethora of cellular processes such as proliferation, differentiation, apoptosis, invasion, and cell migration. Genes in carcinogenesis are classified as oncogenes and tumor suppressors; however, a clear distinction is not always easily made as it depends on the cell context and tissue specificity. The aim of this study is the examination of the potential contribution of MKK3 in cancer through a systematic analysis of the recent literature. The overall results reveal a complex scenario of MKK3’s involvement in cancer. The oncogenic functions of MKK3 were univocally documented in several solid tumors, such as colorectal, prostate cancer, and melanoma, while its tumor-suppressing functions were described in glioblastoma and gastric cancer. Furthermore, a dual role of MKK3 as an oncogene as well as tumor a suppressor has been described in breast, cervical, ovarian, liver, esophageal, and lung cancer. However, overall, more evidence points to its role as an oncogene in these diseases. This review indicates that the oncogenic and tumor-suppressing roles of MKK3 are strictly dependent on the tumor type and further suggests that MKK3 could represent an efficient putative molecular target that requires contextualization within a specific tumor type in order to adequately evaluate its potential effectiveness in designing novel anticancer therapies. 

The p38 MAPK Components and Modulators as Biomarkers and Molecular Targets in Cancer

The mitogen-activated protein kinase (MAPK) family is an important bridge in the transduction of extracellular and intracellular signals in different responses at the cellular level. Within this MAPK family, the p38 kinases can be found altered in various diseases, including cancer, where these kinases play a fundamental role, sometimes with antagonistic mechanisms of action, depending on several factors. In fact, this family has an immense number of functionalities, many of them yet to be discovered in terms of regulation and action in different types of cancer, being directly involved in the response to cancer therapies. To date, three main groups of MAPKs have been identified in mammals: the extracellular signal-regulated kinases (ERK), Jun N-terminal kinase (JNK), and the different isoforms of p38 (α, β, γ, δ). In this review, we highlight the mechanism of action of these kinases, taking into account their extensive regulation at the cellular level through various modifications and modulations, including a wide variety of microRNAs. We also analyze the importance of the different isoforms expressed in the different tissues and their possible role as biomarkers and molecular targets. In addition, we include the latest preclinical and clinical trials with different p38-related drugs that are ongoing with hopeful expectations in the present/future of developing precision medicine in cancer.

Knockdown of Mitogen-Activated Protein Kinase Kinase 3 Negatively Regulates Hepatitis A Virus Replication

Zinc chloride is known to be effective in combatting hepatitis A virus (HAV) infection, and zinc ions seem to be especially involved in Toll-like receptor (TLR) signaling pathways. In the present study, we examined this involvement in human hepatoma cell lines using a human TLR signaling target RT-PCR array. We also observed that zinc chloride inhibited mitogen-activated protein kinase kinase 3 (MAP2K3) expression, which could downregulate HAV replication in human hepatocytes. It is possible that zinc chloride may inhibit HAV replication in association with its inhibition of MAP2K3. In that regard, this study set out to determine whether MAP2K3 could be considered a modulating factor in the development of the HAV pathogen-associated molecular pattern (PAMP) and its triggering of interferon-β production. Because MAP2K3 seems to play a role in antiviral immunity against HAV infection, it is a promising target for drug development. The inhibition of MAP2K3 may also prevent HAV patients from developing a severe hepatitis A infection.

The miR-19b-3p-MAP2K3-STAT3 feedback loop regulates cell proliferation and invasion in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most refractory malignancies worldwide. Mitogen-activated protein kinase 3 (MAP2K3) has a contradictory role in tumor progression, and the function and expression patterns of MAP2K3 in ESCC remain to be determined. We found that MAP2K3 expression to be downregulated in ESCC, and MAP2K3 downregulation correlated with clinically poor survival. MAP2K3 inhibited ESCC cell proliferation and invasion in vitro and in vivo. MAP2K3 suppressed STAT3 expression and activation. Mechanistically, MAPSK3 interacted with MDM2 to promote STAT3 degradation via the ubiquitin-proteasome pathway. Furthermore, exosomal miR-19b-3p derived from the plasma of patients with ESCC could suppress MAP2K3 expression to promote ESCC tumorigenesis. STAT3 was found to bind to the MIR19B promoter and increased the expression of miR-19b-3p in ESCC cells. In summary, our results demonstrated that the miR-19b-3p-MAP2K3-STAT3 feedback loop regulates ESCC tumorigenesis and elucidates the potential of therapeutically targeting this pathway in ESCC.

A Special View of What Was Almost Forgotten: p38δ MAPK

The p38δ mitogen-activated protein kinase is an important signal transduction enzyme. p38δ has recently emerged as a drug target due to its tissue-specific expression patterns and its critical roles in regulation of cellular processes related to cancer and inflammatory diseases, such as cell proliferation, cell migration, apoptosis, and inflammatory responses. However, potent and specific p38δ inhibitors have not been defined so far. Moreover, in cancer disease, p38δ appears to act as a tumor suppressor or tumor promoter according to cancer and cell type studied. In this review, we outline the current understanding of p38δ roles in each cancer type, to define whether it is possible to delineate new cancer therapies based on small-molecule p38δ inhibitors. We also highlight recent advances made in the design of molecules with potential to inhibit p38 isoforms and discuss structural approaches to guide the search for p38δ inhibitors.

High expression of MKK3 is associated with worse clinical outcomes in African American breast cancer patients

BACKGROUND

African American women experience a twofold higher incidence of triple-negative breast cancer (TNBC) and are 40% more likely to die from breast cancer than women of other ethnicities. However, the molecular bases for the survival disparity in breast cancer remain unclear, and no race-specific therapeutic targets have been proposed. To address this knowledge gap, we performed a systematic analysis of the relationship between gene mRNA expression and clinical outcomes determined for The Cancer Genome Atlas (TCGA) breast cancer patient cohort.

METHODS

The systematic differential analysis of mRNA expression integrated with the analysis of clinical outcomes was performed for 1055 samples from the breast invasive carcinoma TCGA PanCancer cohorts. A deep learning fully-convolutional model was used to determine the association between gene expression and tumor features based on breast cancer patient histopathological images.

RESULTS

We found that more than 30% of all protein-coding genes are differentially expressed in White and African American breast cancer patients. We have determined a set of 32 genes whose overexpression in African American patients strongly correlates with decreased survival of African American but not White breast cancer patients. Among those genes, the overexpression of mitogen-activated protein kinase kinase 3 (MKK3) has one of the most dramatic and race-specific negative impacts on the survival of African American patients, specifically with triple-negative breast cancer. We found that MKK3 can promote the TNBC tumorigenesis in African American patients in part by activating of the epithelial-to-mesenchymal transition induced by master regulator MYC.

CONCLUSIONS

The poor clinical outcomes in African American women with breast cancer can be associated with the abnormal elevation of individual gene expression. Such genes, including those identified and prioritized in this study, could represent new targets for therapeutic intervention. A strong correlation between MKK3 overexpression, activation of its binding partner and major oncogene MYC, and worsened clinical outcomes suggests the MKK3-MYC protein-protein interaction as a new promising target to reduce racial disparity in breast cancer survival.

TRIM67 inhibits tumor proliferation and metastasis by mediating MAPK11 in Colorectal Cancer

Purpose: We recently reported that tripartite motif-containing 67 (TRIM67) activates p53 to suppress colorectal cancer (CRC). However, the function and mechanism of TRIM67 in the inhibition of CRC cell proliferation and metastasis remains to be further elucidated.

Methods: We detected the expression of TRIM67 in CRC tissues compared with normal tissues and confirmed its relationship with clinicopathological features. DNA methylation of TRIM67 was analyzed to determine its significantly hypermethylated sites in CRC tissues. CCK-8, colony formation, transwell migration, and Matrigel invasion assays were performed to evaluate the effects of TRIM67 on cell proliferation and metastasis in CRC cells. RNA sequencing of TRIM67 and TRIM67 rescue experiments were performed to reveal its mechanisms in CRC cell proliferation and metastasis.

Results:TRIM67 expression was significantly downregulated in CRC tissues and its expression was associated with clinical stage, invasive depth, tumor size, lymph node metastasis, and Dukes' stage. Three methylation sites were significantly hypermethylated and negatively correlated with TRIM67 expression in CRC tissues. TRIM67 suppressed proliferation, migration, and invasion in CRC cells. RNA sequencing revealed that protein mitogen-activated protein kinase 11 (MAPK11) was a potential downstream negative regulatory gene of TRIM67. Reversing MAPK11 expression could rescue the effects of TRIM67 on the proliferation and metastasis of CRC cells.

Conclusion:TRIM67 inhibited cell proliferation and metastasis by mediating MAPK11 in CRC, and may be a potential target to inhibit CRC metastasis.

An updated patent review of p38 MAP kinase inhibitors (2014-2019)

Introduction: During the first half of the last decade the p38 MAP kinase family was a very popular target in academic as well as industrial research programs. Many attempts to achieve marketing authorization for a p38 MAPK inhibitor for the treatment of pro-inflammatory diseases, like rheumatoid arthritis (RA), failed at the state of clinical trials, mostly due to selectivity and/or toxicity issues.Areas covered: Herein, the patents and corresponding publications of international companies, universities and other research institutions, which focus on the development, identification and optimization of new selective p38 inhibitors and their fields of use are summarized.Expert opinion: p38 MAP kinase inhibitors are a mature field with many pre-clinically validated structural classes, more than 20 candidates in clinical trials but still (except the weak and unselective p38 inhibitor pirfenidone) no approved drug. Big Pharma hasn't contributed much to the patents of the last five years but remarkable contribution have come from academic environment or small biotech companies. Three general punchlines of innovation have shown up. Tailor-made molecules with properties for local application, mainly type-II (Urea-type) inhibitors for lung- or skin diseases, isoform p38γ,δ-selective inhibitors for the treatment of cutaneous t-cell lymphoma (CTCL) and substrate-specific inhibitors (e.g. p38/MK2).

The p38 MAPK Signaling Activation in Colorectal Cancer upon Therapeutic Treatments

Pharmacological treatment of colorectal carcinoma currently proceeds through the administration of a combination of different chemotherapeutic agents. In the case of rectal carcinoma, radiation therapy also represents a therapeutic strategy. In an attempt at translating much-needed new targeted therapy to the clinics, p38 mitogen activated protein kinase (MAPK) inhibitors have been tested in clinical trials involving colorectal carcinoma patients, especially in combination with chemotherapy; however, despite the high expectations raised by a clear involvement of the p38 MAPK pathway in the response to therapeutic treatments, poor results have been obtained so far. In this work, we review recent insights into the exact role of the p38 MAPK pathway in response to currently available therapies for colorectal carcinoma, depicting an intricate scenario in which the p38 MAPK node presents many opportunities, as well as many challenges, for its perspective exploitation for clinical purposes.

The c-Myc/miR-27b-3p/ATG10 regulatory axis regulates chemoresistance in colorectal cancer

Oxaliplatin (OXA) resistance is the major obstacle to the anticancer effects of chemotherapy in colorectal cancer (CRC) patients. MicroRNAs (miRNAs) play an important role in the chemoresistance of various tumors. Our objective is to clarify the underlying mechanism of miRNAs in chemoresistance and provide a potential strategy to improve the response of CRC patients to chemotherapeutics.

Methods: MiRNA microarray and Real-time PCR were performed to compare changes in miRNA expression between oxaliplatin-resistant and the parental cells. CCK8, apoptosis assay, immunofluorescence and xenograft studies were used to elucidate the impact of miR-27b-3p on regulating chemoresistance. Luciferase reporter assay and western blot were carried to assess the regulatory role of miR-27b-3p in ATG10 expression. The effects of miR-27b-3p and ATG10 on autophagy were investigated by GFP-LC3 fluorescence microscopy, transmission electron microscopy, and western blot. ChIP assay and luciferase assay were performed to test the c-Myc's occupancy on the miR-27B promoter.

Results: We observed that miR-27b-3p expression was significantly downregulated in oxaliplatin-resistant cell lines (SW480-OxR and HCT116-OxR) compared to the corresponding parental cell lines and that miR-27b-3p expression was positively correlated with disease-free survival (DFS) time in colorectal cancer patients. MiR-27b-3p could sensitize colorectal cancer cells to oxaliplatin in vitro and in vivo. Under oxaliplatin treatment, chemoresistant cells showed a higher autophagy level than parental cells. Moreover, we also identified that miR-27b-3p inhibited the expression of ATG10 at the posttranscriptional level, thus inhibiting autophagy. Further study demonstrated that c-Myc can inhibit the expression of miR-27b-3p via binding to the promoter region of miR-27B gene.

Conclusions: Our study identifies a novel c-Myc/miR-27b-3p/ATG10 signaling pathway that regulates colorectal cancer chemoresistance. These results suggest that miR-27b-3p is not only a potential indicator for evaluating efficiency of chemotherapy, but also a valuable therapeutic target for CRC, especially for patients with chemoresistance.

Approaching the challenges of MKK3/p38delta MAPK targeting for therapeutic purpose in colorectal cancer

MKK3 is a member of the dual specificity kinase group specific upstream activator of p38 MAPK proteins. We originally identified MKK3 as mutant p53 (mutp53) gain-of-function (GOF) upregulated target gene in different tumor models. To deeply investigate the MKK3 functions in cancer, taking advantage of a panel of authenticated colorectal cancer (CRC) lines and primary colonocytes, we found that MKK3 activates specifically p38delta MAPK protein, which signaling is further triggered by 5-fluorouracil (5-FU) treatments, a largely adopted chemotherapeutic drug in CRC clinical practice. The overall achieved results proposed the MKK3/p38delta MAPK as relevant molecular axis involved in abrogating efficacy to 5-FU treatments in CRC. This commentary will provide an overall discussion of the results that have been achieved contextualizing them in the overview of the knowledge in the p38 MAPK field in cancer disease.