The Role of p53 Dysfunction in Colorectal Cancer and Its Implication for Therapy

A simple and enzyme-free method for sensitive p53 analysis based on DNAzyme-mediated signal amplification

There is an urgent demand for a simple yet extremely accurate biosensor to analyze tumorigenesis. Herein, we present a novel fluorescent and enzyme-free approach for detecting p53 gene cascading proximity ligation-mediated catalytic hairpin assembly and DNAzyme-assisted signal reaction. When the target p53 gene is present, the interaction between p53 and L1 and L2 chains initiates catalytic hairpin assembly and subsequently exposes DNAzyme in the P3 probe. The exposed DNAzyme binds with the loop region of the P4 probe and generates a nicking site, resulting in the release of a significant amount of ATMND that is conjugated in the stem section of P4. This leads to an amplified fluorescence response, which serves as a fluorescence signal for the detection of the p53 gene. This method allows for the accurate and sensitive identification of the p53 gene, exhibiting a linear reaction range of 1 fM to 1 nM, with a limit of detection as low as 0.23 fM. Furthermore, this fluorescent method has been utilized for the examination of clinical samples with a favorable recovery rate. Crucially, this versatile platform may be expanded to analyze different targets by changing the corresponding recognition unit, showing great potential for point-of-care testing in tumorigenesis analysis.

Unraveling the role of long non-coding RNAs in therapeutic resistance in acute myeloid leukemia: New prospects & challenges

Acute Myeloid Leukemia (AML) is a fatal hematological disease characterized by the unchecked proliferation of immature myeloid blasts in different tissues developed by various mutations in hematopoiesis. Despite intense chemotherapeutic regimens, patients often experience poor outcomes, leading to substandard remission rates. In recent years, long non-coding RNAs (lncRNAs) have increasingly become important prognostic and therapeutic hotspots, due to their contributions to dysregulating many functional epigenetic, transcriptional, and post-translational mechanisms leading to alterations in cell expressions, resulting in increased chemoresistance and reduced apoptosis in leukemic cells. Through this review, I highlight and discuss the latest advances in understanding the major mechanisms through which lncRNAs confer therapy resistance in AML. In addition, I also provide perspective on the current strategies to target lncRNA expressions. A better knowledge of the critical role that lncRNAs play in controlling treatment outcomes in AML will help improve existing medications and devise new ones.

Apoptosis: A Comprehensive Overview of Signaling Pathways, Morphological Changes, and Physiological Significance and Therapeutic Implications

Cell survival and death are intricately governed by apoptosis, a meticulously controlled programmed cell death. Apoptosis is vital in facilitating embryonic development and maintaining tissue homeostasis and immunological functioning. It is a complex interplay of intrinsic and extrinsic signaling pathways that ultimately converges on executing the apoptotic program. The extrinsic pathway is initiated by the binding of death ligands such as TNF-α and Fas to their respective receptors on the cell surface. In contrast, the intrinsic pathway leads to increased permeability of the outer mitochondrial membrane and the release of apoptogenic factors like cytochrome c, which is regulated by the Bcl-2 family of proteins. Once activated, these pathways lead to a cascade of biochemical events, including caspase activation, DNA fragmentation, and the dismantling of cellular components. Dysregulation of apoptosis is implicated in various disorders, such as cancer, autoimmune diseases, neurodegenerative disorders, and cardiovascular diseases. This article focuses on elucidating the molecular mechanisms underlying apoptosis regulation, to develop targeted therapeutic strategies. Modulating apoptotic pathways holds immense potential in cancer treatment, where promoting apoptosis in malignant cells could lead to tumor regression. This article demonstrates the therapeutic potential of targeting apoptosis, providing options for treating cancer and neurological illnesses. The safety and effectiveness of apoptosis-targeting drugs are being assessed in ongoing preclinical and clinical trials (phase I-III), opening the door for more effective therapeutic approaches and better patient outcomes.

TP53 mutation status and consensus molecular subtypes of colorectal cancer in patients from Rwanda

BACKGROUND

Mutations in the TP53 tumor suppressor gene are well-established drivers of colorectal cancer (CRC) development. However, data on the prevalence of TP53 variants and their association with consensus molecular subtype (CMS) classification in patients with CRC from Rwanda are currently lacking. This study addressed this knowledge gap by investigating TP53 mutation status concerning CMS classification in a CRC cohort from Rwanda.

METHODS

Formalin-fixed paraffin-embedded (FFPE) tissue blocks were obtained from 51 patients with CRC at the University Teaching Hospital of Kigali, Rwanda. Exons 4 to 11 and their flanking intron-exon boundaries in the TP53 gene were sequenced using Sanger sequencing to identify potential variants. The recently established immunohistochemistry-based classifier was employed to determine the CMS of each tumor.

RESULTS

Sequencing analysis of cancerous tissue DNA revealed TP53 pathogenic variants in 23 of 51 (45.1%) patients from Rwanda. These variants were predominantly missense types (18/23, 78.3%). The most frequent were c.455dup (p.P153Afs*28), c.524G > A (p.R175H), and c.733G > A (p.G245S), each identified in three tumors. Trinucleotide sequence context analysis of the 23 mutations (20 of which were single-base substitutions) revealed a predominance of the [C > N] pattern among single-base substitutions (SBSs) (18/20; 90.0%), with C[C > T]G being the most frequent mutation (5/18, 27.8%). Furthermore, pyrimidine bases (C and T) were preferentially found at the 5' flanking position of the mutated cytosine (13/18; 72.2%). Analysis of CMS subtypes revealed the following distribution: CMS1 (microsatellite instability-immune) (6/51, 11.8%), CMS2 (canonical) (28/51, 54.9%), CMS3 (metabolic) (9/51, 17.6%), and CMS4 (mesenchymal) (8/51, 15.7%). Interestingly, the majority of TP53 variants were in the CMS2 subgroup (14/23; 60.1%).

CONCLUSION

Our findings indicate a high frequency of TP53 variants in CRC patients from Rwanda. Importantly, these variants are enriched in the CMS2 subtype. This study, representing the second investigation into molecular alterations in patients with CRC from Rwanda and the first to explore TP53 mutations and CMS classification, provides valuable insights into the molecular landscape of CRC in this understudied population.

Personalised medicine based on host genetics and microbiota applied to colorectal cancer

Colorectal cancer (CRC) ranks second in incidence and third in cancer mortality worldwide. This situation, together with the understanding of the heterogeneity of the disease, has highlighted the need to develop a more individualised approach to its prevention, diagnosis and treatment through personalised medicine. This approach aims to stratify patients according to risk, predict disease progression and determine the most appropriate treatment. It is essential to identify patients who may respond adequately to treatment and those who may be resistant to treatment to avoid unnecessary therapies and minimise adverse side effects. Current research is focused on identifying biomarkers such as specific mutated genes, the type of mutations and molecular profiles critical for the individualisation of CRC diagnosis, prognosis and treatment guidance. In addition, the study of the intestinal microbiota as biomarkers is being incorporated due to the growing scientific evidence supporting its influence on this disease. This article comprehensively addresses the use of current and emerging diagnostic, prognostic and predictive biomarkers in precision medicine against CRC. The effects of host genetics and gut microbiota composition on new approaches to treating this disease are discussed. How the gut microbiota could mitigate the side effects of treatment is reviewed. In addition, strategies to modulate the gut microbiota, such as dietary interventions, antibiotics, and transplantation of faecal microbiota and phages, are discussed to improve CRC prevention and treatment. These findings provide a solid foundation for future research and improving the care of CRC patients.

The pathological and immunohistochemical profile of tumor angiogenesis in perforated sigmoid carcinoma–Case report and short literature review

<b>Background:</b> Little is known about the physiopathological factors or mechanisms that underlie tumor invasion of the serosa and lead to perforation in the peritoneal cavity. The aim of the work was to analyze the pathological and immunohistochemical factors of tumor neoangiogenesis which could influence tumor perforation in colorectal cancer.<br /> <b>Results and discussions:</b> 451 cases of complicated colorectal carcinomas were statistically analyzed, of which 19 cases were perforated sigmoid tumors. The immunohistochemical detection of mutant p53 proteins was the first molecular parameter examined in the context of the search for markers predicting the natural evolution mode in colorectal carcinomas.<br /> <b>Conclusions</b>: Both loss of p53 and overexpression of bcl-2 proteins confer immortalization on cancer cells by inhibiting the processes leading to apoptosis. The paper proposes a review of the specialized literature, but also the presentation of a clinical case.

PIK3CA Mutated Colorectal Cancers Without KRAS, NRAS and BRAF Mutations Possess Common and Potentially Targetable Mutations in Epigenetic Modifiers and DNA Damage Response Genes

BACKGROUND/AIM

Despite therapeutic advancements, metastatic colorectal cancer is usually fatal, necessitating novel approaches based on the molecular pathogenesis to improve outcomes. Some colorectal cancers have no mutations in the extended RAS panel (KRAS, NRAS, BRAF) genes and represent a special subset, which deserves particular therapeutic considerations.

MATERIALS AND METHODS

The genomic landscape of colorectal cancers from publicly available genomic series was interrogated, using the cBioportal platform. Colorectal cancer cohorts with cancers devoid of KRAS/NRAS or BRAF mutations were evaluated for the presence of mutations in the catalytic sub-unit alpha of kinase PI3K, encoded by the gene PIK3CA.

RESULTS

PIK3CA mutations in the absence of KRAS/NRAS/BRAF mutations were observed in 3.7% to 7.6% of colorectal cancers in the different series examined. Patients with all four genes in wildtype configuration (quadruple wild type) represented 32.2% to 39.9% of cases in the different series examined. Compared with quadruple wild type cancers, triple (KRAS/NRAS/BRAF) wild type/PIK3CA mutated cancers had a higher prevalence of high TMB cases and additional mutations in colorectal cancer associated genes except for mutations in TP53. Mutations in genes encoding for epigenetic modifiers and the DNA damage response (DDR) were also more frequent in triple wild type/PIK3CA mutated cancers. The prognosis of the two groups was comparable.

CONCLUSION

Colorectal cancers with PIK3CA mutations in the absence of KRAS/NRAS/BRAF mutations have frequently mutations in epigenetic modifiers and DDR response genes, which may provide opportunities for targeting. These mutations are present in a smaller subset of quadruple wild type cancers.

From Crypts to Cancer: A Holistic Perspective on Colorectal Carcinogenesis and Therapeutic Strategies

Colorectal cancer (CRC) represents a significant global health burden, with high incidence and mortality rates worldwide. Recent progress in research highlights the distinct clinical and molecular characteristics of colon versus rectal cancers, underscoring tumor location's importance in treatment approaches. This article provides a comprehensive review of our current understanding of CRC epidemiology, risk factors, molecular pathogenesis, and management strategies. We also present the intricate cellular architecture of colonic crypts and their roles in intestinal homeostasis. Colorectal carcinogenesis multistep processes are also described, covering the conventional adenoma-carcinoma sequence, alternative serrated pathways, and the influential Vogelstein model, which proposes sequential APC, KRAS, and TP53 alterations as drivers. The consensus molecular CRC subtypes (CMS1-CMS4) are examined, shedding light on disease heterogeneity and personalized therapy implications.

Comparing Clinicopathological and Immunohistochemical Features of Colorectal Carcinoma between Young and Old Age Groups

The incidence of colorectal carcinoma (CRC) is increasing among individuals younger than 50, and some studies suggest the presence of differences in CRC among old and young individuals regarding clinical and histopathological features. The aim of this study was to compare clinicopathological features, mismatch repair protein status, and expression of certain immunohistochemical stains between young and old groups. The study included 180 cases and found significant histological and immunohistochemical differences between the two groups. CRC in the young tends to be more right-sided and has a higher percentage of dMMR proteins, but less expression of p53 mutations. These features are commoner in Lynch syndrome, and more investigations to study the relationship between young-onset CRC and hereditary syndromes are needed. Young-onset CRC also tends to show higher expression of tumor cell PD-L1, which is an expected finding, as dMMR cases are more likely to be immunogenic. Two other significant differences are the higher percentage of mucinous carcinoma and the higher tumor grade in young-onset CRC. These two features suggest a more advanced disease with possibly worse outcomes; however, there is no difference in disease stage between the two age groups.

Gallium complex K6 inhibits colorectal cancer by increasing ROS levels to induce DNA damage and enhance phosphatase and tensin homolog activity

Colorectal cancer (CRC) is one of the most common malignancies worldwide. In the clinical realm, platinum-based drugs hold an important role in the chemotherapy of CRC. Nonetheless, a multitude of patients, due to tumor protein 53 (TP53) gene mutations, experience the emergence of drug resistance. This phenomenon gravely impairs the effectiveness of therapy and long-term prognosis. Gallium, a metallic element akin to iron, has been reported that has the potential to be used to develop new metal anticancer drugs. In this study, we screened and established the gallium complex K6 as a potent antitumor agent in both in vitro and in vivo. K6 exhibited superior efficacy in impeding the growth, proliferation, and viability of CRC cells carrying TP53 mutations compared to oxaliplatin. Mechanistically, K6 escalated reactive oxygen species levels and led deoxyribonucleic acid (DNA) damage. Furthermore, K6 effectively suppressed the phosphoinositide 3-kinase (PI3K)/protein kinase B (PKB)/glycogen synthase kinase 3 beta (GSK3β) pathway, leading to the degradation of its downstream effectors myelocytomatosis (c-Myc) and Krueppel-like factor 5 (KLF5). Conversely, K6 diminished the protein expression of WW domain-containing protein 1 (WWP1) while activating phosphatase and tensin homolog (PTEN) through c-Myc degradation. This dual action further demonstrated the potential of K6 as a promising therapeutic compound for TP53-mutated CRC.

HIPK2 in Colon Cancer: A Potential Biomarker for Tumor Progression and Response to Therapies

Colon cancer, one of the most common and fatal cancers worldwide, is characterized by stepwise accumulation of specific genetic alterations in tumor suppressor genes or oncogenes, leading to tumor growth and metastasis. HIPK2 (homeodomain-interacting protein kinase 2) is a serine/threonine protein kinase and a "bona fide" oncosuppressor protein. Its activation inhibits tumor growth mainly by promoting apoptosis, while its inactivation increases tumorigenicity and resistance to therapies of many different cancer types, including colon cancer. HIPK2 interacts with many molecular pathways by means of its kinase activity or transcriptional co-repressor function modulating cell growth and apoptosis, invasion, angiogenesis, inflammation and hypoxia. HIPK2 has been shown to participate in several molecular pathways involved in colon cancer including p53, Wnt/β-catenin and the newly identified nuclear factor erythroid 2 (NF-E2) p45-related factor 2 (NRF2). HIPK2 also plays a role in tumor-host interaction in the tumor microenvironment (TME) by inducing angiogenesis and cancer-associated fibroblast (CAF) differentiation. The aim of this review is to assess the role of HIPK2 in colon cancer and the underlying molecular pathways for a better understanding of its involvement in colon cancer carcinogenesis and response to therapies, which will likely pave the way for novel colon cancer therapies.

Unveiling the impact of glutathione (GSH) and p53 gene deletion on tumor cell metabolism by amino acid and proteomics analysis

Background

Tumor cell inhibition is a pivotal focus in anti-cancer research, and extensive investigations have been conducted regarding the role of p53. Numerous studies have highlighted its close association with reactive oxygen species (ROS). However, the precise impact of the antioxidant glutathione (GSH) in this context remains inadequately elucidated. Here, we will elucidate the anti-cancer mechanisms mediated by p53 following treatment with GSH.

Methods

In this study, we employed a p53 gene knockout approach in SW480 colorectal cells and conducted comprehensive analyses of 20 amino acids and proteomics using liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS).

Results

These analyses unveiled profound alterations in amino acids and proteins triggered by GSH treatment, shedding light on novel phenomena and delineating the intricate interplay between GSH and cellular proteins. The deletion of the p53 gene exerts a profound influence on tumor cell proliferation. Moreover, tumor cell proliferation is significantly affected by elevated GSH levels. Importantly, in the absence of the p53 gene, cells exhibit heightened sensitivity to GSH, leading to inhibited cell growth. The combined therapeutic approach involving GSH and p53 gene deletion expedites the demise of tumor cells. It is noteworthy that this treatment leads to a marked decline in amino acid metabolism, particularly affecting the down-regulation of methionine (Met) and phenylalanine (Phe) amino acids. Among the 41 proteins displaying significant changes, 8 exhibit consistent alterations, with 5 experiencing decreased levels and 3 demonstrating increased quantities. These proteins primarily participate in crucial cellular metabolic processes and immune functions.

Conclusions

In conclusion, the concurrent administration of GSH treatment and p53 gene deletion triggers substantial modifications in the amino acid and protein metabolism of tumor cells, primarily characterized by down-regulation. This, in turn, compromises cell metabolic activity and immune function, ultimately culminating in the demise of tumor cells. These newfound insights hold promising implications and could pave the way for the development of straightforward and efficacious anti-cancer treatments.

Synthesis and characterisation of a nucleotide based pro-drug formulated with a peptide into a nano-chemotherapy for colorectal cancer

Recent studies in colorectal cancer patients (CRC) have shown that increased resistance to thymidylate synthase (TS) inhibitors such as 5-fluorouracil (5-FU), reduce the efficacy of standard of care (SoC) treatment regimens. The nucleotide pool cleanser dUTPase is highly expressed in CRC and is an attractive target for potentiating anticancer activity of chemotherapy. The purpose of the current work was to investigate the activity of P1, P4-di(2',5'-dideoxy-5'-selenouridinyl)-tetraphosphate (P4-SedU2), a selenium-modified symmetrically capped dinucleoside with prodrug capabilities that is specifically activated by dUTPase. Using mechanochemistry, P4-SedU2 and the corresponding selenothymidine analogue P4-SeT2 were prepared with a yield of 19% and 30% respectively. The phosphate functionality facilitated complexation with the amphipathic cell-penetrating peptide RALA to produce nanoparticles (NPs). These NPs were designed to deliver P4-SedU2 intracellularly and thereby maximise in vivo activity. The NPs demonstrated effective anti-cancer activity and selectivity in the HCT116 CRC cell line, a cell line that overexpresses dUTPase; compared to HT29 CRC cells and NCTC-929 fibroblast cells which have reduced levels of dUTPase expression. In vivo studies in BALB/c SCID mice revealed no significant toxicity with respect to weight or organ histology. Pharmacokinetic analysis of blood serum showed that RALA facilitates effective delivery and rapid internalisation into surrounding tissues with NPs eliciting lower plasma Cmax than the equivalent injection of free P4-SedU2, translating the in vitro findings. Tumour growth delay studies have demonstrated significant inhibition of growth dynamics with the tumour doubling time extended by >2weeks. These studies demonstrate the functionality and action of a new pro-drug nucleotide for CRC.

The histological and molecular characteristics of early-onset colorectal cancer: a systematic review and meta-analysis

Background

Early-onset colorectal cancer (CRC), defined as diagnosis before age 50, has increased in recent decades. Although more often diagnosed at advanced stage, associations with other histological and molecular markers that impact prognosis and treatment remain to be clarified. We conducted a systematic review and meta-analysis concerning the prevalence of prognostic and predictive tumor markers for early- vs. late-onset CRC, including oncogene mutations, microsatellite instability (MSI), and emerging markers including immune cells and the consensus molecular subtypes.

Methods

We systematically searched PubMed for original research articles published between April 2013-January 2024. Included studies compared the prevalence of tumor markers in early- vs. late-onset CRC. A meta-analysis was completed and summary odds ratios (ORs) with 95% confidence intervals (CIs) were obtained from a random effects model via inverse variance weighting. A sensitivity analysis was completed to restrict the meta-analysis to studies that excluded individuals with Lynch syndrome, a hereditary condition that influences the distribution of tumor markers for early-onset CRC.

Results

In total, 149 articles were identified. Tumors from early-onset CRC are less likely to include mutations in KRAS (OR, 95% CI: 0.91, 0.85-0.98), BRAF (0.63, 0.51-0.78), APC (0.70, 0.58-0.84), and NRAS (0.88, 0.78-1.00) but more likely to include mutations in PTEN (1.68, 1.04-2.73) and TP53 (1.34, 1.24-1.45). After limiting to studies that excluded Lynch syndrome, the associations between early-onset CRC and BRAF (0.77, 0.64-0.92) and APC mutation (0.81, 0.67-0.97) were attenuated, while an inverse association with PIK3CA mutation was also observed (0.88, 0.78-0.99). Early-onset tumors are less likely to develop along the CpG Island Methylator Phenotype pathway (0.24, 0.10-0.57), but more likely to possess adverse histological features including high tumor grade (1.20, 1.15-1.25), and mucinous (1.22, 1.16-1.27) or signet ring histology (2.32, 2.08-2.57). A positive association with MSI status (1.31, 1.11-1.56) was also identified. Associations with immune markers and the consensus molecular subtypes are inconsistent.

Discussion

A lower prevalence of mutations in KRAS and BRAF is consistent with extended survival and superior response to targeted therapies for metastatic disease. Conversely, early-onset CRC is associated with aggressive histological subtypes and TP53 and PTEN mutations, which may serve as therapeutic targets.

Tumor location matters, next generation sequencing mutation profiling of left-sided, rectal, and right-sided colorectal tumors in 552 patients

Despite the introduction of new molecular classifications, advanced colorectal cancer (CRC) is treated with chemotherapy supplemented with anti-EGFR and anti-VEGF targeted therapy. In this study, 552 CRC cases with different primary tumor locations (250 left side, 190 rectum, and 112 right side) were retrospectively analyzed by next generation sequencing for mutations in 50 genes. The most frequently mutated genes were TP53 in left-sided tumors compared to right-sided tumors and BRAF in right-sided tumors compared to left-sided tumors. Mutations in KRAS, NRAS, and BRAF were not detected in 45% of patients with left-sided tumors and in 28.6% of patients with right-sided tumors. Liver metastases were more common in patients with left-sided tumors. Tumors on the right side were larger at diagnosis and had a higher grade (G3) than tumors on the left. Rectal tumors exhibit distinctive biological characteristics when compared to left-sided tumors, including a higher absence rate of KRAS, NRAS, and BRAF mutations (47.4% in rectal versus 42.8% in left-sided tumors). These rectal tumors are also unique in their primary metastasis site, which is predominantly the lungs, and they have varying mutation rates, particularly in genes such as BRAF, FBXW7, and TP53, that distinguish them from tumors found in other locations. Primary tumor location has implications for the potential treatment of CRC with anti-EGFR therapy.

Circulating Tumor DNA Profiling in Liver Transplant for Hepatocellular Carcinoma, Cholangiocarcinoma, and Colorectal Liver Metastases: A Programmatic Proof of Concept

INTRODUCTION

Circulating tumor DNA (ctDNA) is emerging as a promising, non-invasive diagnostic and surveillance biomarker in solid organ malignancy. However, its utility before and after liver transplant (LT) for patients with primary and secondary liver cancers is still underexplored.

METHODS

Patients undergoing LT for hepatocellular carcinoma (HCC), cholangiocarcinoma (CCA), and colorectal liver metastases (CRLM) with ctDNA testing were included. CtDNA testing was conducted pre-transplant, post-transplant, or both (sequential) from 11/2019 to 09/2023 using Guardant360, Guardant Reveal, and Guardant360 CDx.

RESULTS

21 patients with HCC (n = 9, 43%), CRLM (n = 8, 38%), CCA (n = 3, 14%), and mixed HCC/CCA (n = 1, 5%) were included in the study. The median follow-up time was 15 months (range: 1-124). The median time from pre-operative testing to surgery was 3 months (IQR: 1-4; range: 0-5), and from surgery to post-operative testing, it was 9 months (IQR: 2-22; range: 0.4-112). A total of 13 (62%) patients had pre-transplant testing, with 8 (62%) having ctDNA detected (ctDNA+) and 5 (32%) not having ctDNA detected (ctDNA-). A total of 18 (86%) patients had post-transplant testing, 11 (61%) of whom were ctDNA+ and 7 (33%) of whom were ctDNA-. The absolute recurrence rates were 50% (n = 5) in those who were ctDNA+ vs. 25% (n = 1) in those who were ctDNA- in the post-transplant setting, though this difference was not statistically significant (p = 0.367). Six (29%) patients (HCC = 3, CCA = 1, CRLM = 2) experienced recurrence with a median recurrence-free survival of 14 (IQR: 6-40) months. Four of these patients had positive post-transplant ctDNA collected following diagnosis of recurrence, while one patient had positive post-transplant ctDNA collected preceding recurrence. A total of 10 (48%) patients had sequential ctDNA testing, of whom n = 5 (50%) achieved ctDNA clearance (+/-). The remainder were ctDNA+/+ (n = 3, 30%), ctDNA-/- (n = 1, 10%), and ctDNA-/+ (n = 1, 11%). Three (30%) patients showed the acquisition of new genomic alterations following transplant, all without recurrence. Overall, the median tumor mutation burden (TMB) decreased from 1.23 mut/Mb pre-transplant to 0.00 mut/Mb post-transplant.

CONCLUSIONS

Patients with ctDNA positivity experienced recurrence at a higher rate than the ctDNA- patients, indicating the potential role of ctDNA in predicting recurrence after curative-intent transplant. Based on sequential testing, LT has the potential to clear ctDNA, demonstrating the capability of LT in the treatment of systemic disease. Transplant providers should be aware of the potential of donor-derived cell-free DNA and improved approaches are necessary to address such concerns.

Targeted regulated cell death with small molecule compounds in colorectal cancer: Current perspectives of targeted therapy and molecular mechanisms

Colorectal cancer (CRC), a tumor of the digestive system, is characterized by high malignancy and poor prognosis. Currently, targeted therapy of CRC is far away from satisfying. The molecular mechanisms of regulated cell death (RCD) have been clearly elucidated, which can be intervened by drug or genetic modification. Numerous studies have provided substantial evidence linking these mechanisms to the progression and treatment of CRC. The RCD includes apoptosis, autophagy-dependent cell death (ADCD), ferroptosis, necroptosis, and pyroptosis, and immunogenic cell death, etc, which provide potential targets for anti-cancer treatment. For the last several years, small-molecule compounds targeting RCD have been a well concerned therapeutic strategy for CRC. This present review aims to describe the function of small-molecule compounds in the targeted therapy of CRC via targeting apoptosis, ADCD, ferroptosis, necroptosis, immunogenic dell death and pyroptosis, and their mechanisms. In addition, we prospect the application of newly discovered cuproptosis and disulfidptosis in CRC. Our review may provide references for the targeted therapy of CRC using small-molecule compounds targeting RCD, including the potential targets and candidate compounds.

The rational modulation of autophagy sensitizes colorectal cancer cells to 5-fluouracil and oxaliplatin

Colorectal cancer (CRC) is the third most common and deadliest cancer globally. Regimens using 5-fluorouracil (5FU) and Oxaliplatin (OXA) are the first-line treatment for CRC, but tumor recurrence is frequent. It is plausible to hypothesize that differential cellular responses are triggered after treatments depending on the genetic background of CRC cells and that the rational modulation of cell tolerance mechanisms like autophagy may reduce the regrowth of CRC cells. This study proposes investigating the cellular mechanisms triggered by CRC cells exposed to 5FU and OXA using a preclinical experimental design mimicking one cycle of the clinical regimen (i.e., 48 h of treatment repeated every 2 weeks). To test this, we treated CRC human cell lines HCT116 and HT29 with the 5FU and OXA, combined or not, for 48 h, followed by analysis for two additional weeks. Compared to single-drug treatments, the co-treatment reduced tumor cell regrowth, clonogenicity and stemness, phenotypes associated with tumor aggressiveness and poor prognosis in clinics. This effect was exerted by the induction of apoptosis and senescence only in the co-treatment. However, a week after treatment, cells that tolerated the treatment had high levels of autophagy features and restored the proliferative phenotype, resembling tumor recurrence. The pharmacologic suppression of early autophagy during its peak of occurrence, but not concomitant with chemotherapeutics, strongly reduced cell regrowth. Overall, our experimental model provides new insights into the cellular mechanisms that underlie the response and tolerance of CRC cells to 5FU and OXA, suggesting optimized, time-specific autophagy inhibition as a new avenue for improving the efficacy of current treatments.

Deciphering treatment resistance in metastatic colorectal cancer: roles of drug transports, EGFR mutations, and HGF/c-MET signaling

In 2023, colorectal cancer (CRC) is the third most diagnosed malignancy and the third leading cause of cancer death worldwide. At the time of the initial visit, 20% of patients diagnosed with CRC have metastatic CRC (mCRC), and another 25% who present with localized disease will later develop metastases. Despite the improvement in response rates with various modulation strategies such as chemotherapy combined with targeted therapy, radiotherapy, and immunotherapy, the prognosis of mCRC is poor, with a 5-year survival rate of 14%, and the primary reason for treatment failure is believed to be the development of resistance to therapies. Herein, we provide an overview of the main mechanisms of resistance in mCRC and specifically highlight the role of drug transports, EGFR, and HGF/c-MET signaling pathway in mediating mCRC resistance, as well as discuss recent therapeutic approaches to reverse resistance caused by drug transports and resistance to anti-EGFR blockade caused by mutations in EGFR and alteration in HGF/c-MET signaling pathway.

Prognostic and immunological role of adaptor related protein complex 3 subunit mu2 in colon cancer

The expression levels and prognostic role of AP3M2 in colorectal adenocarcinoma (CRAC) have yet to be fully unveiled. Our study comprehensively investigated the clinical significance of AP3M2 in colorectal cancer through an extensive bioinformatics data mining process (TCGA, GEO, GEPIA, Timer, Ualcan, ROCPLOT, and David), followed by experimental validation. We found AP3M2 is a cancer gene, which can be used to distinguish between colorectal cancer and colorectal adenomas, liver metastasis, lung metastasis, colorectal polyp. Higher AP3M2 expression levels were associated with longer overall survival in colon adenocarcinoma. AP3M2 might be the primary biomarker for oxaliplatin in colon cancer and an acquired resistance biomarker for oxaliplatin and 5-fu. AP3M2 was positively associated with CD274, CTLA4. AP3M2 might be associated with T-cell, NF-kappaB transcription factor activity, and response to hypoxia. AP3M2 could predict chemotherapy effectiveness and prognosis for colon cancer patients. AP3M2 might inhibit tumor growth via influencing tumor-infiltrating immune cells in the context of Tumor microenvironment. AP3M2 plays as an oncogene in CRAC and is suggested as a new potential biotarget for therapy.

Multiple Protein Biomarkers and Different Treatment Strategies for Colorectal Carcinoma: A Comprehensive Prospective

In this review, we emphasized important biomarkers, pathogenesis, and newly developed therapeutic approaches in the treatment of colorectal cancer (CRC). This includes a complete description of small-molecule inhibitors, phytopharmaceuticals with antiproliferative potential, monoclonal antibodies for targeted therapy, vaccinations as immunotherapeutic agents, and many innovative strategies to intervene in the interaction of oncogenic proteins. Many factors combine to determine the clinical behavior of colorectal cancer and it is still difficult to comprehend the molecular causes of a person's vulnerability to CRC. It is also challenging to identify the causes of the tumor's onset, progression, and responsiveness or resistance to antitumor treatment. Current recommendations for targeted medications are being updated by guidelines throughout the world in light of the growing number of high-quality clinical studies. So, being concerned about the aforementioned aspects, we have tried to present a summarized pathogenic view, including a brief description of biomarkers and an update of compounds with their underlying mechanisms that are currently under various stages of clinical testing. This will help to identify gaps or shortfalls that can be addressed in upcoming colorectal cancer research.

Thymoquinone: A Promising Therapeutic Agent for the Treatment of Colorectal Cancer

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers and is responsible for approximately one million deaths each year. The current standard of care is surgical resection of the lesion and chemotherapy with 5-fluorouracil (5-FU). However, of concern is the increasing incidence in an increasingly younger patient population and the ability of CRC cells to develop resistance to 5-FU. In this review, we discuss the effects of thymoquinone (TQ), one of the main bioactive components of Nigella sativa seeds, on CRC, with a particular focus on the use of TQ in combination therapy with other chemotherapeutic agents. TQ exhibits anti-CRC activity by inducing a proapoptotic effect and inhibiting proliferation, primarily through its effect on the regulation of signaling pathways crucial for tumor progression and oxidative stress. TQ can be used synergistically with chemotherapeutic agents to enhance their anticancer effects and to influence the expression of signaling pathways and other genes important in cancer development. These data appear to be most relevant for co-treatment with 5-FU. We believe that TQ is a suitable candidate for consideration in the chemoprevention and adjuvant therapy for CRC, but further studies, including clinical trials, are needed to confirm its safety and efficacy in the treatment of cancer.

TP53 Alteration and Its Effect on Pathologic Response Are Associated with Survival after Resection of Colorectal Liver Metastases

The aims of this study were to assess the effect of known gene alterations (RAS, TP53, APC, SMAD4, BRAF, and FBXW7) on pathologic response (PR) and their combined association with survival in patients with colorectal liver metastases (CLM). From a prospectively maintained database, we collected data on 458 patients who underwent curative-intent hepatectomy after receiving the first-line preoperative chemotherapy between 2004 and 2020. Major PR was defined as tumor viability of less than 50% in all tumors. Multivariate logistic regression revealed that oxaliplatin-containing regimen (OR: 2.54, 95% CI: 1.58-4.07, P < 0.001), bevacizumab-containing regimen (OR: 2.15, 95%CI: 1.36-3.39, P = 0.001), and TP53 alteration (OR: 0.42, 95%CI: 0.27-0.66, P < 0.001) were independently associated with major PR. Multivariate Cox regression also revealed that patients with TP53 wild-type and major PR (HR: 0.49, 95%CI: 0.31-0.77, P = 0.002) and those with TP53 alteration and major PR (HR: 0.70, 95%CI: 0.49-1.00, P = 0.048) had significantly better overall survival compared to those with minor PR. Further studies targeting the association of TP53 with PR and survival can help clarify the role of TP53 in CLM.

Unveiling the genetic and epigenetic landscape of colorectal cancer: new insights into pathogenic pathways

Colorectal cancer (CRC) is a complex disease characterized by genetic and epigenetic alterations, playing a crucial role in its development and progression. This review aims to provide insights into the emerging landscape of these alterations in CRC pathogenesis to develop effective diagnostic tools and targeted therapies. Genetic alterations in signaling pathways such as Wnt/β-catenin, and PI3K/Akt/mTOR are pivotal in CRC development. Genetic profiling has identified distinct molecular subtypes, enabling personalized treatment strategies. Epigenetic modifications, including DNA methylation and histone modifications, also contribute to CRC pathogenesis by influencing critical cellular processes through gene silencing or activation. Non-coding RNAs have emerged as essential players in epigenetic regulation and CRC progression. Recent research highlights the interplay between genetic and epigenetic alterations in CRC. Genetic mutations can affect epigenetic modifications, leading to dysregulated gene expression and signaling cascades. Conversely, epigenetic changes can modulate genetic expression, amplifying or dampening the effects of genetic alterations. Advancements in understanding pathogenic pathways have potential clinical applications. Identifying genetic and epigenetic markers as diagnostic and prognostic biomarkers promises more accurate risk assessment and early detection. Challenges remain, including validating biomarkers and developing robust therapeutic strategies through extensive research and clinical trials. The dynamic nature of genetic and epigenetic alterations necessitates a comprehensive understanding of their temporal and spatial patterns during CRC progression. In conclusion, the genetic and epigenetic landscape of CRC is increasingly being unraveled, providing valuable insights into its pathogenesis. Integrating genetic and epigenetic knowledge holds great potential for improving diagnostics, prognostics, and personalized therapies in CRC. Continued research efforts are vital to translate these findings into clinical practice, ultimately improving patient outcomes.

Quinacrine enhances the efficacy of cisplatin by increasing apoptosis and modulating cancer survival proteins in a colorectal cancer cell line

BACKGROUND

Cisplatin and platinum-based compounds have been used successfully to treat various cancers. However, their use is often restricted due to the acquired resistance by cancer cells. Over-expression of p53 and inhibition of NF-kB sensitize several cancer cells towards cisplatin-induced apoptosis. Quinacrine, a cytotoxic drug with predictable safety revealed to concurrently suppress NF-kB and activate p53, which may be an attractive adjuvant in cisplatin chemotherapy. Therefore, the objective of the present study was to establish the role of quinacrine as an adjuvant in lowering the dose of cisplatin during cancer therapy to circumvent its toxic effects.

MATERIALS AND METHODS

The colon cancer (HCT-8) cells were cultured and cell survival assays were performed using standard procedures. Cell cycle arrest and the extent of apoptosis were determined using a muse cell analyzer. Cancer survival proteins were analyzed using western blotting techniques.

RESULTS AND CONCLUSION

We demonstrated that concomitant use of quinacrine with cisplatin increased cell apoptosis, suppressed cell proliferation and inhibited colony formation in a colorectal cancer cell line. Moreover, cell cycle arrest in the G0/G1 and G2/M phases and upregulation of p53 expression were observed. There was also downregulation of NF-kB and Bcl-xL protein expressions, both of which are associated with enhanced cell apoptosis and an increase in the sensitivity of cancer cells to cisplatin, overcoming its chemoresistance. Overall, the results of the present study and available literature clearly indicate that the use of quinacrine as an adjuvant with cisplatin may enhance its anti-cancer activity and reduce chemoresistance.

Evaluation of enterotoxigenic Bacteroides fragilis correlation with the expression of cellular signaling pathway genes in Iranian patients with colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is one of the most common cancers all over the world, and dysbiosis in the gut microbiota may play a role in colorectal carcinogenesis. Bacteroides fragilis can lead to tumorigenesis by changing signaling pathways, including the WNT/β-catenin pathway. Therefore, in the present study, we investigated the correlation between the enterotoxigenic B. fragilis amount and the expression of signaling pathway genes involved in CRC.

MATERIALS AND METHODS

B. fragilis was determined in 30 tumors and adjacent healthy tissues by the qPCR method. Next, the relationship between enterotoxigenic B. fragilis and the expression of signaling pathway genes, including CCND1, TP53, BCL2, BAX, WNT, TCF, AXIN, APC, and CTNNB1 was investigated. Additionally, possible correlations between clinicopathological features of the tumor samples and the abundance of B. fragilis were analyzed.

RESULTS

The results showed that B. fragilis was detected in 100% of tumor samples and 86% of healthy tissues. Additionally, enterotoxigenic B. fragilis colonized 47% of all samples, and bft-1 toxin was the most frequently found isotype among the samples. The analysis showed that the high level of B. fragilis has a significant relationship with the high expression of AXIN, CTNNB1, and BCL2 genes. On the other hand, our results did not show any possible correlation between this bacterium and the clinicopathological features of the tumor sample.

CONCLUSION

B. fragilis had a higher abundance in the tumor samples than in healthy tissues, and this bacterium may lead to CRC by making changes in cellular signaling pathways and genes. Therefore, to better understand the physiological effects of B. fragilis on the inflammatory response and CRC, future research should focus on dissecting the molecular mechanisms by which this bacterium regulates cellular signaling pathways.

Bilirubin, an endogenous antioxidant that affects p53 protein and its downstream apoptosis/autophagy-related genes in LS180 and SW480 cell culture models of colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is one of the commonest neoplasms worldwide, which its pathogenesis is strongly correlated with p53 mutations. Antioxidants are believed to decelerate the CRC progression, possibly through interfering with p53 and its downstream target genes and mechanisms. Regarding the potential antioxidant effects of bilirubin, as an incredible endogenous antioxidant, we sought to investigate how bilirubin affected the expression levels of p53 protein and its downstream target genes, including Mdm2, Bcl-2, BECN1 and LC3, in LS180 and SW480 cell culture models of CRC.

METHODS AND RESULTS

Using the MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide) assay, 50 and 100 μM concentrations of bilirubin were determined to be non-toxic for both LS180 and SW480 cell lines. Western blot analysis was employed to evaluate the protein expression levels of p53. The results revealed that p53 protein levels were higher in LS180 cells treated with bilirubin compared to the control group. Notwithstanding, in SW480 cells, no considerable changes were observed in p53 protein levels of treated cells compared to the control ones. The quantitative reverse transcriptase-polymerase chain reaction (q RT-PCR) method was used to measure the mRNA expression levels of the apoptosis/autophagy-related genes, Mdm2, Bcl-2, BECN1, and LC3 , as the p53's downstream target genes. Consequently, the expression of Bcl-2 and Mdm2 genes were affected by p53, while BECN1 and LC3 expression levels were decreased in both cell lines.

CONCLUSION

Bilirubin is an endogenous antioxidant with significant anti-tumor effects in the studied CRC cell lines, probably through the regulation of p53 protein expression levels and subsequent control of apoptosis and autophagy, as two key processes involved in cell survival and progression of tumor cells.

Anticancer efficacy of hirsuteine against colorectal cancer by opposite modulation of wild-type and mutant p53

PURPOSE

The present study aimed to explore the anticancer activity of hirsuteine (HST), an indole alkaloid from the traditional Chinese herbal medicine Uncaria rhynchophylla, against colorectal cancer (CRC) and the underlining mechanism.

METHODS

MTT, colony formation, flow cytometry and MDC staining were conducted to confirm the antiproliferative effect of HST on human CRC cells harboring different p53 status. Protein expressions were evaluated by the Western blot analysis. p53 protein half-life and the interaction between p53 and MDM2 were investigated using cycloheximide (CHX)-chase assay and Co-immunoprecipitation (Co-IP), respectively. Transcriptional activity of p53 was examined by qRT-PCR and Chromatin immunoprecipitation (ChIP). Xenograft tumor in nude mice was created to evaluate in vivo anticancer effect of HST against CRC.

RESULTS

HST inhibited cell growth, arrested cell cycle and induced autophagy, showing efficient anticancer effects on CRC cells independent of p53 status. In HCT-8 cells, HST prolonged wtp53 half-life, and upregulated mRNA level of p21, suggesting that HST activated the p53 pathway through enhancement of wtp53 stability and transcriptional activity. Meanwhile in SW620 cells, HST induced MDM2-mediated proteasomal degradation of mutp53^R273H, increased the DNA-binding ability of mutp53^R273H at the p21 promoter, and upregulated mRNA levels of p21 and MDM2, demonstrating the depletion of mutp53^R273H and restoration of its wild-type-like properties by HST. p53 knockdown by siRNA significantly impaired the growth inhibition of HST on HCT-8 and SW620 cells. Moreover, HST showed anticancer effects in xenograft tumors, accompanied with an opposite regulation of wtp53 and mutp53 ^R273H in mechanism.

CONCLUSION

This study revealed the anticancer efficacy of HST against CRC via opposite modulation of wtp53 and mutp53 ^R273H, indicating the potential of HST to be a CRC drug candidate targeting p53 signaling.

Riok1, A Novel Potential Target in MSI-High p53 Mutant Colorectal Cancer Cells

The vulnerabilities of cancer cells constitute a promising strategy for drug therapeutics. This paper integrates proteomics, bioinformatics, and cell genotype together with in vitro cell proliferation assays to identify key biological processes and potential novel kinases that could account, at least in part, for the clinical differences observed in colorectal cancer (CRC) patients. This study started by focusing on CRC cell lines stratified by their microsatellite (MS) state and p53 genotype. It shows that cell-cycle checkpoint, metabolism of proteins and RNA, signal transduction, and WNT signaling processes are significantly more active in MSI-High p53-WT cell lines. Conversely, MSI-High cell lines with a mutant (Mut) p53 gene showed hyperactivation of cell signaling, DNA repair, and immune-system processes. Several kinases were linked to these phenotypes, from which RIOK1 was selected for additional exploration. We also included the KRAS genotype in our analysis. Our results showed that RIOK1's inhibition in CRC MSI-High cell lines was dependent on both the p53 and KRAS genotypes. Explicitly, Nintedanib showed relatively low cytotoxicity in MSI-High with both mutant p53 and KRAS (HCT-15) but no inhibition in p53 and KRAS WT (SW48) MSI-High cells. This trend was flipped in CRC MSI-High bearing opposite p53-KRAS genotypes (e.g., p53-Mut KRAS-WT or p53-WT KRAS-Mut), where observed cytotoxicity was more extensive compared to the p53-KRAS WT-WT or Mut-Mut cells, with HCT 116 (KRAS-Mut and p53-WT) being the most sensitive to RIOK1 inhibition. These results highlight the potential of our in silico computational approach to identify novel kinases in CRC sub-MSI-High populations as well as the importance of clinical genomics in determining drug potency.

Metastatic colorectal cancer: mechanisms and emerging therapeutics

Metastatic colorectal cancer (mCRC) remains a lethal disease with an approximately 14% 5-year survival rate. While early-stage colorectal cancer (CRC) can be cured by surgery with or without adjuvant chemotherapy, mCRC cannot be eradicated due to a large burden of disseminated cancer cells comprising therapy-resistant metastasis-competent cells. To address this gap, recent studies have focused on further elucidating the molecular mechanisms underlying colorectal metastasis and recognizing the limitations of available therapeutic interventions. In this review, we discuss newfound factors that regulate CRC cell dissemination and colonization of distant organs, such as genetic mutations, identification of metastasis-initiating cells (MICs), epithelial-mesenchymal transition (EMT), and the tumor microenvironment (TME). We also review current treatments for mCRC, therapeutic regimens undergoing clinical trials, and trending preclinical studies being investigated to target treatment-resistant mCRC.

Mutant P53 in the formation and progression of the tumor microenvironment: Friend or foe

TP53 is the most frequently mutated gene in human cancer. It encodes the tumor suppressor protein p53, which suppresses tumorigenesis by acting as a critical transcription factor that can induce the expression of many genes controlling a plethora of fundamental cellular processes, including cell cycle progression, survival, apoptosis, and DNA repair. Missense mutations are the most frequent type of mutations in the TP53 gene. While these can have variable effects, they typically impair p53 function in a dominant-negative manner, thereby altering intra-cellular signaling pathways and promoting cancer development. Additionally, it is becoming increasingly apparent that p53 mutations also have non-cell autonomous effects that influence the tumor microenvironment (TME). The TME is a complex and heterogeneous milieu composed of both malignant and non-malignant cells, including cancer-associated fibroblasts (CAFs), adipocytes, pericytes, different immune cell types, such as tumor-associated macrophages (TAMs) and T and B lymphocytes, as well as lymphatic and blood vessels and extracellular matrix (ECM). Recently, a large body of evidence has demonstrated that various types of p53 mutations directly affect TME. They fine-tune the inflammatory TME and cell fate reprogramming, which affect cancer progression. Notably, re-educating the p53 signaling pathway in the TME may be an effective therapeutic strategy in combating cancer. Therefore, it is timely to here review the recent advances in our understanding of how TP53 mutations impact the fate of cancer cells by reshaping the TME.

A novel strategy for precise prognosis management and treatment option in colon adenocarcinoma with TP53 mutations

Background

TP53 is one of the most frequent mutated genes in colon cancer. Although colon cancer with TP53 mutations has a high risk of metastasis and worse prognosis generally, it showed high heterogeneity clinically.

Methods

A total of 1,412 colon adenocarcinoma (COAD) samples were obtained from two RNA-seq cohorts and three microarray cohorts, including the TCGA-COAD (N = 408), the CPTAC-COAD (N = 106), GSE39582 (N = 541), GSE17536 (N = 171) and GSE41258 (N = 186). The LASSO-Cox method was used to establish the prognostic signature based on the expression data. The patients were divided into high-risk and low-risk groups based on the median risk score. The efficiency of the prognostic signature was validated in various cohorts, including TP53-mutant and TP53 wild-type. The exploration of potential therapeutic targets and agents was performed by using the expression data of TP53-mutant COAD cell lines obtained from the CCLE database and the corresponding drug sensitivity data obtained from the GDSC database.

Results

A 16-gene prognostic signature was established in TP53-mutant COAD. The high-risk group had significantly inferior survival time compared to the low-risk group in all TP53-mutant datasets, while the prognostic signature failed to classify the prognosis of COAD with TP53 wild-type properly. Besides, the risk score was the independent poor factor for the prognosis in TP53-mutant COAD and the nomogram based on the risk score was also shown good predictive efficiency in TP53-mutant COAD. Moreover, we identified SGPP1, RHOQ, and PDGFRB as potential targets for TP53-mutant COAD, and illuminated that the high-risk patients might benefit from IGFR-3801, Staurosporine, and Sabutoclax.

Conclusion

A novel prognostic signature with great efficiency was established especially for COAD patients with TP53 mutations. Besides, we identified novel therapeutic targets and potential sensitive agents for TP53-mutant COAD with high risk. Our findings provided not only a new strategy for prognosis management but also new clues for drug application and precision treatment in COAD with TP53 mutations.

Wnt3a is a promising target in colorectal cancer

Most colorectal cancers (CRC) are associated with activated Wnt signaling, making it the fourth most prevalent type of cancer globally. To function properly, the Wnt signaling pathway requires secreted glycoproteins known as Wnt ligands (Wnts). Humans have 19 Wnts, which suggest a complicated signaling and biological process, and we still know little about their functions in developing CRC. This review aims to describe the canonical Wnt signaling in CRC, particularly the Wnt3a expression pattern, and their association with the angiogenesis and progression of CRC. This review also sheds light on the inhibition of Wnt3a signaling in CRC. Despite some obstacles, a thorough understanding of Wnts is essential for effectively managing CRC.

Metabolism-Guided Optimization of Tryptophanol-Derived Isoindolinone p53 Activators

For the first time, the pharmacokinetic (PK) profile of tryptophanol-derived isoindolinones, previously reported as p53 activators, was investigated. From the metabolites' identification, performed by liquid chromatography coupled to high resolution tandem mass spectrometry (LC-HRMS/MS), followed by their preparation and structural elucidation, it was possible to identify that the indole C2 and C3 are the main target of the cytochrome P450 (CYP)-promoted oxidative metabolism in the tryptophanol-derived isoindolinone scaffold. Based on these findings, to search for novel p53 activators a series of 16 enantiopure tryptophanol-derived isoindolinones substituted with a bromine in indole C2 was prepared, in yields of 62-89%, and their antiproliferative activity evaluated in human colon adenocarcinoma HCT116 cell lines with and without p53. Structural optimization led to the identification of two (S)-tryptophanol-derived isoindolinones 3.9-fold and 1.9-fold more active than hit SLMP53-1, respectively. Compounds' metabolic stability evaluation revealed that this substitution led to a metabolic switch, with the impact of Phase I oxidative metabolism being minimized. Through differential scanning fluorimetry (DSF) experiments, the most active compound of the series in cell assays led to an increase in the protein melting temperature (Tm) of 10.39 °C, suggesting an effective binding to wild-type p53 core domain.

Associations between serum vitamin D biomarkers and tumor expression of Ki67, p53, and COX-2 in colorectal cancer cases from the Southern Community Cohort Study

Higher 25-hydroxyvitamin D is associated with lower colorectal cancer (CRC) risk, with limited data from African Americans (AAs), who have greater risk for CRC and 25-hydroxyvitamin D deficiency. In a predominantly AA sample of CRC cases from the Southern Community Cohort Study (SCCS), we report associations between vitamin D biomarkers and tumor expression of proteins implicated in vitamin D's anti-tumorigenic pathways (e.g. proliferation and inflammation) and CRC prognosis. SCCS participants with incident CRC were identified via state cancer registries. Serum 25-hydroxyvitamin D and vitamin D binding protein (VDBP) were measured at enrollment. 'Free' 25-hydroxyvitamin D was calculated via standard equation. Cellular Ki67, p53, and COX-2 were measured from tumor samples and categorized using literature-defined cut-points related to survival. Generalized linear models were used to measure associations between vitamin D exposures, tumor biomarkers, and stage. In total, 104 cases (40-79 years) were analyzed. 25-hydroxyvitamin D was not associated with high Ki67 (odds ratio (OR) per 1-standard deviation (SD) increase [95% confidence interval] 1.35[0.86-2.11]), p53 (0.75[0.47-1.20]), or COX-2 expression (1.25[0.78-2.01]), or metastatic disease (1.04[0.59-1.81]). Mean biomarker expression was unrelated to 25-hydroxyvitamin D (p-trend ≥.09). Null associations were observed for VDBP and free 25-hydroxyvitamin D. In AAs (n = 70), higher VDBP was associated with lower odds of high Ki67 expression (0.53[0.28-0.98], p-trend =.04). In conclusion, we observed no associations between 25-hydroxyvitamin D and prognostic marker expression in CRC. An inverse association between VDBP and tumor Ki67 in AAs is consistent with reports showing relationships with reduced CRC mortality.

Proapoptotic and Antiproliferative Effects of the Desert Truffle Terfezia boudieri on Colon Cancer Cell Lines

Background

Colon cancer is the second leading cause of cancer-related mortality, and ranks third among cancers in terms of prevalence. Despite advances in early detection and treatment with chemotherapy and surgery, colon cancer continues to be associated with high recurrence rates, thereby resulting in a heavy disease burden. Moreover, the effectiveness of currently available treatment modalities is limited by the occurrence of toxic side effects. Hence, there is an urgent need to develop alternative treatments. Extracts from the black desert truffle Terfezia boudieri (T. boudieri) have shown promising anticancer properties. However, the cellular mechanisms underlying this activity remain poorly understood.

Methods

In this study, the colon cancer cell lines HCT-116 and Caco-2 were treated with either water or ethanolic extract of T. boudieri. Cell viability and the half-maximal inhibitory concentration were determined using MTT assays. Then, the activity of the more potent water extract was further verified using crystal violet assays, and its role in inhibiting colony formation and wound healing was investigated. Protein levels of p53, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X (Bax), cyclin D1 (CCND1), and c-Myc were measured in cells treated with different doses of the water extract.

Results

Treatment with the water extract of T. boudieri reduced the capacity of cells for wound healing and colony formation in a dose-dependent manner. The Bax/Bcl-2 ratio and p53 expression were elevated in both cell lines. In contrast, the levels of cyclin D1 and c-Myc were suppressed.

Conclusion

T. boudieri water extract exerted a cytotoxic effect on colon cancer cells, and blocked colony formation and wound healing potentially through inhibition of proliferation. Mechanistically, these effects are attributed to influence the mitochondrial pathway of apoptosis, proteins involved in cellular proliferation, and the cell cycle.

Molecular and cellular pathways in colorectal cancer: apoptosis, autophagy and inflammation as key players

BACKGROUND

Colorectal carcinogenesis (CRC) is one of the most aggressive forms of cancer, particularly in developing countries. It accounts for the second and third-highest reason for cancer-induced lethality in women and men respectively. CRC involves genetic and epigenetic modifications in colonic epithelium, leading to colon adenocarcinoma. The current review highlights the pathogenic mechanisms and multifactorial etiology of CRC, influenced by apoptosis, inflammation, and autophagy pathways.

METHODS

We have carried out a selective literature review on mechanisms contributing to the pathogenesis of CRC.

RESULTS

Resistance to senescence and apoptosis of the mesenchymal cells, which play a key role in intestinal organogenesis, morphogenesis and homeostasis, appears important for sporadic CRC. Additionally, inflammation-associated tumorigenesis is a key incident in CRC, supported by immune disruptors, adaptive and innate immune traits, environmental factors, etc. involving oxidative stress, DNA damage and epigenetic modulations. The self-digesting mechanism, autophagy, also plays a twin role in CRC through the participation of LC3/LC3-II, Beclin-1, ATG5, other autophagy proteins, and Inflammatory Bowel Disease (IBD) susceptibility genes. It facilitates the promotion of effective surveillance pathways and stimulates the generation of malignant tumor cells. The autophagy and apoptotic pathways undergo synergistic or antagonistic interactions in CRC and bear a critical association with IBD that results from the pro-neoplastic effects of persistent intestinal inflammation. Conversely, pro-inflammatory factors stimulate tumor growth and angiogenesis and inhibit apoptosis, suppressing anti-tumor activities.

CONCLUSION

Hence, research attempts for the development of potential therapies for CRC are in progress, primarily based on combinatorial approaches targeting apoptosis, inflammation, and autophagy.

Effect of TP53 deficiency and KRAS signaling on the bioenergetics of colon cancer cells in response to different substrates: A single cell study

Metabolic reprogramming is a hallmark of cancer. Somatic mutations in genes involved in oncogenic signaling pathways, including KRAS and TP53, rewire the metabolic machinery in cancer cells. We here set out to determine, at the single cell level, metabolic signatures in human colon cancer cells engineered to express combinations of activating KRAS gene mutations and TP53 gene deletions. Specifically, we explored how somatic mutations in these genes and substrate availability (lactate, glucose, substrate deprivation) from the extracellular microenvironment affect bioenergetic parameters, including cellular ATP, NADH and mitochondrial membrane potential dynamics. Employing cytosolic and mitochondrial FRET-based ATP probes, fluorescent NADH sensors, and the membrane-permeant cationic fluorescent probe TMRM in HCT-116 cells as a model system, we observed that TP53 deletion and KRAS mutations drive a shift in metabolic signatures enabling lactate to become an efficient metabolite to replenish both ATP and NADH following nutrient deprivation. Intriguingly, cytosolic, mitochondrial and overall cellular ATP measurements revealed that, in WT KRAS cells, TP53 deficiency leads to an enhanced ATP production in the presence of extracellular lactate and glucose, and to the greatest increase in ATP following a starvation period. On the other hand, oncogenic KRAS in TP53-deficient cells reversed the alterations in cellular ATP levels. Moreover, cell population measurements of mitochondrial and glycolytic metabolism using a Seahorse analyzer demonstrated that WT KRAS TP53-silenced cells display an increase of the basal respiration and tightly-coupled mitochondria, in the presence of glucose as substrate, compared to TP53 competent cells. Furthermore, cells possessing oncogenic KRAS, independently of TP53 status, showed less pronounced mitochondrial membrane potential changes in response to metabolic nutrients. Furthermore, analysis of cytosolic and mitochondrial NADH levels revealed that the simultaneous presence of TP53 deletion and oncogenic KRAS showed the most pronounced alteration in cytosolic and mitochondrial NADH during metabolic stress. In conclusion, our findings demonstrate how activating KRAS mutation and loss of TP53 remodel cancer metabolism and lead to alterations in bioenergetics under metabolic stress conditions by modulating cellular ATP production, NADH oxidation, mitochondrial respiration and function.

Deletion of cystathionine-γ-lyase in bone marrow-derived cells promotes colitis-associated carcinogenesis

Ulcerative colitis (UC) is characterized by widespread relapsing inflammation of the colonic mucosa. Colitis-associated cancer (CAC) is one of the most serious complications of a prolonged history of UC. Hydrogen sulfide (H2S) has emerged as an important physiological mediator of gastrointestinal homeostasis, limiting mucosal inflammation and promoting tissue healing in response to injury. Inhibition of cystathionine-γ-lyase (CSE)-dependent H2S production in animal models of UC has been shown to exacerbate colitis and delay tissue repair. It is unknown whether CSE plays a role in CAC, or the downregulation of CSE expression and/or activity promotes CAC development. In humans, we observed a significant decrease in CSE expression in colonic biopsies from patients with UC. Using the dextran sodium sulfate (DSS) model of epithelium injury-induced colitis and global CSE KO mouse strain, we demonstrated that CSE is critical in limiting mucosal inflammation and stimulating epithelial cell proliferation in response to injury. In vitro studies showed that CSE activity stimulates epithelial cell proliferation, basal and cytokine-stimulated cell migration, as well as cytokine regulation of transepithelial permeability. In the azoxymethane (AOM)/DSS model of CAC, the loss of CSE expression accelerated both the development and progression of CAC. The increased tumor multiplicity and severity of CAC observed in CSE-KO mice were associated with reduced levels of mucosal IL-10 expression and increased levels of IL-6. Restoring CSE expression in bone marrow (BM) cells of CSE-KO mice through reciprocal BM transplantation raised mucosal IL-10 expression, decreased IL-6 level, and reduced the number of aberrant crypt foci and tumors in AOM/DSS-treated mice. These studies demonstrate that CSE expression in BM cells plays a critical role in suppressing CAC in mice. Furthermore, the data suggest that the inhibitory effects of CSE on the development of CAC are due, in part, to the modulation of mucosal pro-and anti-inflammatory cytokine expression.

What Surgeons Need to Know About Gene Therapy for Cancer

The broad field of gene therapy offers numerous innovative approaches for cancer treatment. An understanding of the different modalities including gene replacement therapy, cancer vaccines, oncolytic viruses, cellular therapy, and gene editing is essential for managing patients with neoplastic disease. As in other areas of oncology, the surgeon plays a pivotal role in the diagnosis and treatment of the disease. This review focuses on what the clinical surgeon needs to know to optimize the benefit of gene therapy for patients with cancer.

Molecular Profiling of Tumor Tissue in Mexican Patients with Colorectal Cancer

Colorectal cancer is a heterogeneous disease with multiple genomic changes that influence the clinical management of patients; thus, the search for new molecular targets remains necessary. The aim of this study was to identify genetic variants in tumor tissues from Mexican patients with colorectal cancer, using massive parallel sequencing. A total of 4813 genes were analyzed in tumoral DNA from colorectal cancer patients, using the TruSight One Sequencing panel. From these, 192 variants with clinical associations were found distributed in 168 different genes, of which 46 variants had not been previous reported in the literature or databases, although genes harboring those variants had already been described in colorectal cancer. Enrichment analysis of the affected genes was performed using Reactome software; pathway over-representation showed significance for disease, signal transduction, and immune system subsets in all patients, while exclusive subsets such as DNA repair, autophagy, and RNA metabolism were also found. Those characteristics, whether individual or shared, could give tumors specific capabilities for survival, aggressiveness, or response to treatment. Our results can be useful for future investigations targeting specific characteristics of tumors in colorectal cancer patients. The identification of exclusive or common pathways in colorectal cancer patients could be important for better diagnosis and personalized cancer treatment.

High Expression of CUL9 Is Prognostic and Predictive for Adjuvant Chemotherapy in High-Risk Stage II and Stage III Colon Cancer

We evaluated the clinical implications of CUL9 expression on the prognosis and the predictive value for adjuvant chemotherapy in colon cancer. A total of 1078 consecutive patients treated with radical resection from 2008 to 2012 were included. Formalin-fixed, paraffin-embedded specimens were used as immunohistochemistry (IHC) for CUL9. For all patients, high expression of CUL9 was identified as an independent prognostic factor for overall survival (HR = 1.613, 95% CI 1.305−1.993, p < 0.001) and disease-free survival (HR = 1.570, 95% CI 1.159−2.128, p = 0.004). The prognostic value of high CUL9 expression was confirmed in an independent validation cohort from the GEO database. The efficacy of adjuvant chemotherapy was analyzed among patients with high-risk stage II and stage III disease. Those with high CUL9 expression from the full dose group had better disease-free survival (HR = 0.477, 95% CI 0.276−0.825, p = 0.006) than those from the reduced dose group. The interaction test between CUL9 expression and the treatment reached significance and was not confounded by T stage, N stage and histopathological grade. In general, high expression of CUL9 was an independent prognostic factor in patients with colon cancer. In those with high-risk stage II and stage III disease, high expression of CUL9 was associated with the benefit from standard 6-months adjuvant chemotherapy regimens.

Ferroptosis-based nano delivery systems targeted therapy for colorectal cancer: Insights and future perspectives

There are limited options for patients who develop liver metastasis from colorectal cancer (CRC), the leading cause of cancer-related mortality worldwide. Emerging evidence has provided insights into iron deficiency and excess in CRC. Ferroptosis is an iron-dependent form of programmed cell death characterized by aberrant iron and lipid metabolism, which play crucial roles in tumorigenesis, tumor progression, and treatment options. A better understanding of the underlying molecular mechanism of ferroptosis has shed light on the current findings of ferroptosis-based nanodrug targeting strategies, such as driving ferroptosis in tumor cells and the tumor microenvironment, emerging combination therapy and against multidrug resistance. Furthermore, this review highlights the challenge and perspective of a ferroptosis-driven nanodrug delivery system for CRC-targeted therapy.

Network Pharmacology and Molecular Docking on the Molecular Mechanism of Jiawei-Huang Lian-Gan Jiang Decoction in the Treatment of Colorectal Adenomas

Purpose

Jiawei-Huang Lian-Gan Jiang decoction (JWHLGJD) was developed to treat and prevent the patients with colorectal adenomas (CRA) in China. This study is aimed to discover JWHLGJD's active compounds and demonstrate mechanisms of JWHLGJD against CRA through network pharmacology and molecular docking techniques.

Methods

All the components of JWHLGJD were retrieved from the pharmacology database of Traditional Chinese Medicine Systems Pharmacology (TCMSP). The GeneCards database, the Online Mendelian Inheritance in Man database (OMIM), the DrugBank database, and PharmGKB were used to obtain the genes matching the targets. Cytoscape created the compound-target network. The network of target protein-protein interactions (PPI) was constructed using the STRING database. Gene Ontology (GO) functional and the Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathways involved in the targets were analyzed by using the DAVID database. Cytoscape created the component-target-pathway (C-T-P) network. AutoDock Vina software was used to verify the molecular docking of JWHLGJD components and key targets. Core genes linked with survival and tumor microenvironment were analyzed through the Kaplan–Meier plotter and TIMER 2.0 databases, respectively.

Results

Compound-target network mainly contained 38 compounds and 130 targets of the JWHLGJD associated with CRA. TP53, MAPK1, JUN, HSP90AA1, and AKT1 were identified as core targets by the PPI network. KEGG pathway shows that the pathways in cancer, lipids, and atherosclerosis, PI3K-Akt signaling pathway and MAPK signaling pathway, are the most relevant pathways to CRA. The C-T-P network suggests that the active component in JWHLGJD is capable of regulating target genes of these related pathways. The results of molecular docking showed that berberine and stigmasterol were the top two compounds of JWHLGJD, which had high affinity with TP53 and MAPK1, respectively. And, MAPK1 exerted a more significant effect on the prognosis of adenocarcinoma, for it was highly associated with various immune cells.

Conclusion

Findings in this study provided light on JWHLGJD's active components, prospective targets, and molecular mechanism. It also gave a potential way to uncovering the scientific underpinning and therapeutic mechanism of traditional Chinese medicine (TCM) formulas.

Liver Endothelium Promotes HER3-mediated Cell Survival in Colorectal Cancer with Wild-type and Mutant KRAS

We previously identified that human epidermal growth factor receptor 3 (HER3, also known as ERBB3) is a key mediator in liver endothelial cell (EC) promoting colorectal cancer (CRC) growth and chemoresistance, and suggested HER3-targeted therapy as a strategy for treating patients with metastatic CRC (mCRC) in the liver. Meanwhile, KRAS mutations occur in 40-50% of mCRC and render CRC resistant to therapies targeting the other HER family protein epidermal growth factor receptor (EGFR). It is necessary to elucidate the roles of KRAS mutation status in HER3-mediated cell survival and CRC response to HER3 inhibition. In the present study, we used primary ECs isolated from non-neoplastic liver tissues to recapitulate the liver EC microenvironment. We demonstrated that liver EC-secreted factors activated CRC-associated HER3, and increased CRC cell survival in vitro and promoted CRC patient-derived xenograft tumor growth in vivo. Moreover, we determined that blocking HER3, either by siRNA knockdown or the humanized antibody seribantumab, blocked EC-induced CRC survival in vitro in both KRAS wild-type and mutant CRC cells, and the HER3 antibody seribantumab significantly decreased CRC tumor growth and sensitized tumors to chemotherapy in an orthotopic xenograft model with CRC tumors developed in the liver. In summary, our findings demonstrated that blocking HER3 had significant effects on attenuating liver EC-induced CRC cell survival independent of the KRAS mutation status. Implications: This body of work highlighted a potential strategy of using HER3 antibodies in combination with standard chemotherapy agents for treating patients with either KRAS wild-type or KRAS mutant mCRC.

Immunotherapy for Colorectal Cancer: Mechanisms and Predictive Biomarkers

Simple Summary

Late-stage colorectal cancer treatment often involves chemotherapy and radiation that can cause dose-limiting toxicity, and therefore there is great interest in developing targeted therapies for this disease. Immunotherapy is a targeted therapy that uses peptides, cells, antibodies, viruses, or small molecules to engage or train the immune system to kill cancer. Here, we discuss the preclinical and clinical development of immunotherapy for treatment of colorectal cancer and provide an overview of predictive biomarkers for such treatments. We also consider open questions including optimal combination treatments and sensitization of colorectal cancer patients with proficient mismatch repair enzymes.

Abstract

Though early-stage colorectal cancer has a high 5 year survival rate of 65–92% depending on the specific stage, this probability drops to 13% after the cancer metastasizes. Frontline treatments for colorectal cancer such as chemotherapy and radiation often produce dose-limiting toxicities in patients and acquired resistance in cancer cells. Additional targeted treatments are needed to improve patient outcomes and quality of life. Immunotherapy involves treatment with peptides, cells, antibodies, viruses, or small molecules to engage or train the immune system to kill cancer cells. Preclinical and clinical investigations of immunotherapy for treatment of colorectal cancer including immune checkpoint blockade, adoptive cell therapy, monoclonal antibodies, oncolytic viruses, anti-cancer vaccines, and immune system modulators have been promising, but demonstrate limitations for patients with proficient mismatch repair enzymes. In this review, we discuss preclinical and clinical studies investigating immunotherapy for treatment of colorectal cancer and predictive biomarkers for response to these treatments. We also consider open questions including optimal combination treatments to maximize efficacy, minimize toxicity, and prevent acquired resistance and approaches to sensitize mismatch repair-proficient patients to immunotherapy.

Therapeutic Potential of Naturally Occurring Small Molecules to Target the Wnt/β-Catenin Signaling Pathway in Colorectal Cancer

Simple Summary

Colorectal cancer (CRC) is an emerging public health problem and the second leading cause of death worldwide, with a significant socioeconomic impact in several countries. The 5-year survival rate is only 12% due to the lack of early diagnosis and resistance to available treatments, and the canonical Wnt signaling pathway is involved in this process. This review underlines the importance of understanding the fundamental roles of this pathway in physiological and pathological contexts and analyzes the use of naturally occurring small molecules that inhibits the Wnt/β-catenin pathway in experimental models of CRC. We also discuss the progress and challenges of moving these small molecules off the laboratory bench into the clinical platform.

Abstract

Colorectal cancer (CRC) ranks second in the number of cancer deaths worldwide, mainly due to late diagnoses, which restrict treatment in the potentially curable stages and decrease patient survival. The treatment of CRC involves surgery to remove the tumor tissue, in addition to radiotherapy and systemic chemotherapy sessions. However, almost half of patients are resistant to these treatments, especially in metastatic cases, where the 5-year survival rate is only 12%. This factor may be related to the intratumoral heterogeneity, tumor microenvironment (TME), and the presence of cancer stem cells (CSCs), which is impossible to resolve with the standard approaches currently available in clinical practice. CSCs are APC-deficient, and the search for alternative therapeutic agents such as small molecules from natural sources is a promising strategy, as these substances have several antitumor properties. Many of those interfere with the regulation of signaling pathways at the central core of CRC development, such as the Wnt/β-catenin, which plays a crucial role in the cell proliferation and stemness in the tumor. This review will discuss the use of naturally occurring small molecules inhibiting the Wnt/β-catenin pathway in experimental CRC models over the past decade, highlighting the molecular targets in the Wnt/β-catenin pathway and the mechanisms through which these molecules perform their antitumor activities.

Clinical Impact of X-Ray Repair Cross-Complementary 1 (XRCC1) and the Immune Environment in Colorectal Adenoma-Carcinoma Pathway Progression

Purpose

Colorectal cancer (CRC) can develop via a hypermutagenic pathway characterized by frequent somatic DNA base-pair mutations. Alternatively, the immunogenicity of tumor cells themselves may influence the anticancer activity of the immune effector cells. Impaired DNA repair mechanisms drive mutagenicity, which then increase the neoantigen load and immunogenicity. However, no studies have analyzed immune checkpoint protein expression, particularly programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1), in adenoma–carcinoma progression and its relationship with the emergence of other DNA repair gene mutation.

Materials and Methods

We investigated mutations of 10 genes involved in DNA repair function: XRCC1, TP53, MLH1, MSH, KRAS, GSTP, UMP, MTHF, DPYD, and ABCC2. We performed sequencing to determine mutations and immunohistochemistry of immune checkpoints in clinical samples and determined changes in XRCC1 expression during progression through the adenoma–carcinoma pathway. We further investigated the prognostic associations of gene XRCC1 according to the expression, mutational profile, and immune profile using The Cancer Genome Atlas-colon adenocarcinoma (TCGA-COAD) dataset.

Results

From clinical samples, XRCC1 mutation demonstrated the strongest association with adenomas with a mutation frequency of 56.2% in adenomas and 34% in CRCs (p =0.016). XRCC1 was abnormally expressed and altered by mutations contributing to adenoma carcinogenesis. High expression of XRCC1, CD4, FOXP3, and PD-1/PD-L1 showed an overall upward trend with increased lesion severity (all p < 0.01). PD-1/PD-L1 expression and CD4+ intraepithelial lymphocytes (IELs) correlated with cytological dysplasia progression, specifically in patients with wild-type XRCC1 (all p < 0.01), whereas FOXP3 expression was independently associated with adenoma–carcinoma progression. From TCGA-COAD analysis, XRCC1 expression was associated with patients survival, tumor-infiltrating lymphocytes and immune marker expression.

Conclusion

Increased IEL density and PD-1/PD-L1 expression correlate with cytological dysplasia progression and specifically with the XRCC1 mutation status in CRC. Our findings support a stepwise dysplasia-carcinoma sequence of adenoma carcinogenesis and an XRCC1 hypermutated phenotypic mechanism of lesions.

The Role of p53 in Progression of Cutaneous Squamous Cell Carcinoma

Skin cancers are the most common types of cancer worldwide, and their incidence is increasing. Melanoma, basal cell carcinoma (BCC), and cutaneous squamous cell carcinoma (cSCC) are the three major types of skin cancer. Melanoma originates from melanocytes, whereas BCC and cSCC originate from epidermal keratinocytes and are therefore called keratinocyte carcinomas. Chronic exposure to ultraviolet radiation (UVR) is a common risk factor for skin cancers, but they differ with respect to oncogenic mutational profiles and alterations in cellular signaling pathways. cSCC is the most common metastatic skin cancer, and it is associated with poor prognosis in the advanced stage. An important early event in cSCC development is mutation of the TP53 gene and inactivation of the tumor suppressor function of the tumor protein 53 gene (TP53) in epidermal keratinocytes, which then leads to accumulation of additional oncogenic mutations. Additional genomic and proteomic alterations are required for the progression of premalignant lesion, actinic keratosis, to invasive and metastatic cSCC. Recently, the role of p53 in the invasion of cSCC has also been elucidated. In this review, the role of p53 in the progression of cSCC and as potential new therapeutic target for cSCC will be discussed.