P53 represses pyrimidine catabolic gene dihydropyrimidine dehydrogenase (DPYD) expression in response to thymidylate synthase (TS) targeting

P53: A key player in diverse cellular processes including nuclear stress and ribosome biogenesis, highlighting potential therapeutic compounds

The tumor suppressor proteins are key transcription factors involved in the regulation of various cellular processes, such as apoptosis, DNA repair, cell cycle, senescence, and metabolism. The tumor suppressor protein p53 responds to different type of stress signaling, such as hypoxia, DNA damage, nutrient deprivation, oncogene activation, by activating or repressing the expression of different genes that target processes mentioned earlier. p53 has the ability to modulate the activity of many other proteins and signaling pathway through protein-protein interaction, post-translational modifications, or non-coding RNAs. In many cancers the p53 is found to be mutated or inactivated, resulting in the loss of its tumor suppressor function and acquisition of new oncogenic properties. The tumor suppressor protein p53 also plays a role in the development of other metabolic disorders such as diabetes, obesity, and fatty liver disease. In this review, we will summarize the current data and knowledge on the molecular mechanisms and the functions of p53 in different pathways and processes at the cellular level and discuss the its implications for human health and disease.

An SNP Marker Predicts Colorectal Cancer Outcomes with 5-Fluorouracil-Based Adjuvant Chemotherapy Post-Resection

Colorectal cancer (CRC) is a global health concern, necessitating adjuvant chemotherapy post-curative surgery to mitigate recurrence and enhance survival, particularly in intermediate-stage patients. However, existing therapeutic disparities highlight the need for biomarker-guided adjuvant chemotherapy to achieve better CRC inhibition. This study explores the molecular mechanisms underlying the inhibition of CRC through a genome-wide association study (GWAS) focused on 5-fluorouracil (5-FU)-based adjuvant therapy in intermediate-stage CRC patients, a domain previously unexplored. We retrospectively included 226 intermediate-stage CRC patients undergoing surgical resection followed by 5-FU-based adjuvant chemotherapy. The exploration cohort comprised 31 patients, and the validation cohort included 195 individuals. Genotyping was carried out using either Axiom Genome-Wide TWB 2.0 Array Plate-based or polymerase chain reaction-based methods on genomic DNA derived from collected tissue samples. Statistical analyses involved descriptive statistics, Kaplan-Meier analyses, and Cox proportional hazard analyses. From the GWAS, potential genetic predictors, GALNT14-rs62139523 and DNMBP-rs10786578 genotypes, of 5-FU-based adjuvant therapy following surgery in intermediate-stage CRC patients were identified. Validation in a larger cohort of 195 patients emphasized the predictive significance of GALNT14-rs62139523 genotypes, especially the "A/G" genotype, for improved overall and progression-free survival. This predictive association remained robust across various subgroups, with exceptions for specific demographic and clinical parameters such as age < 58 years old, CEA ≤ 2.5 ng/mL, tumor diameter > 44.0 mm, and tumor-free margin ≥ 50 mm. This study identifies that the GALNT14-rs62139523 "A/G" genotype modulates therapeutic outcomes, establishing it as a promising biomarker for predicting favorable responses to 5-FU-based adjuvant chemotherapy in intermediate-stage CRC patients, although further investigations are needed to detail these mechanisms.

Preparation of nanoformulation of 5-fluorouracil to improve anticancer efficacy: integrated spectroscopic, docking, and MD simulation approaches

Nanoformulations (NFs) can be used as a novel drug delivery system to treat all cancer types. One of the major drawbacks of conventional anticancer drugs is that they have poor specificity and higher toxicity towards normal cells. 5-fluorouracil (5-FU) is a well-studied anticancer drug that has a significant role in various cancers, specifically colorectal cancer therapy. This study was performed to determine the functional groups, particle size, surface charge, heterogeneity, and stability of the NF. The NFs of 5-FU were prepared through the ultrasonication technique by increasing the surfactant (Tween-80) concentrations. Among all three NFs, nanoformulated 5-FU (n5-FU) showed the most effective particle size (10.72 nm) with a zeta potential of (-4.57 mV). The cytotoxicity and apoptosis profiles confirmed that n5-FU enhanced the anticancer effect of the pure drug in HCT-116 cells, as evident from MTT assay, fluorescence microscopy, and FACS analysis. In HCT-116 cells, the IC50 values of pure and n5-FU were obtained as 41.3 μM and 18.8 μM, respectively, indicating that n5-FU was more effective against the cancer cell line. The cellular uptake study was performed to check the intake of NF in cancer cells. However, the microtubule-affinity regulating kinase-4 (MARK-4), a cancer-target protein, was purified to study the inhibition and interaction studies. The inhibition assay confirmed the inhibitory potential of 5-FU against MARK-4 protein. the multi-spectroscopic, molecular docking and MD simulation studies were performed to analyse the conformational changes, binding studies, intermolecular interactions, and stability of MARK-4 protein upon binding 5-FU. This demonstrates that NF can enhance the effectiveness of anticancer drugs.Communicated by Ramaswamy H. Sarma.

A multivariate metal–organic framework based pH-responsive dual-drug delivery system for chemotherapy and chemodynamic therapy

By combining two different ligands and metals, MOFs can be fine-tuned for effective encapsulation and delivery of two anticancer drugs.

Fluoropyrimidine‑induced cardiotoxicity in colorectal cancer patients: a prospective observational trial (CHECKPOINT)

Fluoropyrimidines (FP) are the backbone chemotherapy in colorectal cancer (CRC) treatment; however, their use is associated with cardiotoxicity, which is underreported. In the present study, it was aimed to prospectively determine the incidence rates and related risk factors of FP‑induced cardiotoxicity (FIC) in CRC patients and at identifying predictive biomarkers. A total of 129 consecutive previously untreated CRC patients underwent active cardiological monitoring, including 5‑items simplified questionnaire on symptoms, electrocardiogram (ECG) and plasma sample collection during FP chemotherapy. FIC was defined as the presence of ECG alterations and/or the arising of at least one symptom of chest pain, dyspnoea, palpitations or syncope. The primary objective was the evaluation of FIC incidence. Secondary objectives were the correlation of FIC with well‑known cardiological risk factors and the identification of circulating biomarkers (serum levels of troponin I, pro hormone BNP; miRNA analysis) as predictors of FIC. A total of 20 out of 129 (15.5%) patients experienced FIC. The most common symptoms were dyspnoea (60%) and chest pain (40%), while only 15% of patients presented ECG alterations, including one acute myocardial infarction. Retreatment with FP was attempted in 90% of patients with a favourable outcome. Despite 48% of patients having cardiological comorbidities, an increased FIC was not observed in this subgroup. Only the subgroup of females with the habit of alcohol consumption showed an increased risk of FIC. None of the circulating biomarkers evaluated demonstrated a clinical utility as FIC predictors. FIC can be an unexpected, life‑threatening adverse event that can limit the subsequent treatment choices in patients with CRC. In this prospective study, well‑known cardiological comorbidities were not related to higher FIC risk and circulating biomarkers predictive of toxicity could not be found. With careful monitoring, mainly based on symptoms, almost all patients completed the FP treatment.

Gene expression responses reflecting 5-FU-induced toxicity: Comparison between patient colon tissue and 3D human colon organoids

Capecitabine is a chemotherapeutic drug that is widely used as a monotherapy option in advanced cancer patients. After administration, it is converted into its active metabolite 5-fluorouracil (5-FU), a cytotoxic compound that may also induce adverse side effects in the gastrointestinal (GI) tract. Although these side effects can interfere with the continuation of the chemotherapy, diagnostic tools to detect early onset and prevention strategies are not available. In this explorative case study, we aim to identify differentially expressed genes (DEGs) that provide insight into the molecular mechanisms of toxicity induced by 5-FU in healthy colon tissue of breast cancer patients receiving capecitabine. Gene expression responses observed in patients were compared with those established in an in vitro model of healthy colon organoids. Colon biopsies from two patients with advanced breast cancer were collected before and after the treatment with capecitabine and used for RNA sequencing to determine transcriptomic responses. Differential expression analysis resulted in 31 affected genes, showing that the most affected pathways were transport of small molecules, cellular responses to stress, folate metabolism, NF-kB signalling pathway and immune system responses. The most biologically relevant genes were haemoglobin subunits encoding genes, involved in several processes; ATP12A, SLC26A3 and AQP8, involved in the transport of ions and water; TRIM31, a regulator of NF-kB signalling pathway; MST1P2 and MST1L, stimulators of macrophages. Comparison of human in vitro and in vivo responses showed that the gene expression of TRIM31 was similarly altered in the colon organoids exposed to 5-FU. Therefore, this gene constitutes a potential biomarker of colon toxicity that might be used in future in vitro drug safety design and screening.

Regulation of thymidylate synthase: an approach to overcome 5-FU resistance in colorectal cancer

Thymidylate synthase is the rate-limiting enzyme required for DNA synthesis and overexpression of this enzyme causes resistance to cancer cells. Long treatments with 5-FU cause resistance to Thymidylate synthase targeting drugs. We have also compiled different mechanisms of drug resistance including autophagy and apoptosis, drug detoxification and ABC transporters, drug efflux, signaling pathways (AKT/PI3K, RAS-MAPK, WNT/β catenin, mTOR, NFKB, and Notch1 and FOXM1) and different genes associated with resistance in colorectal cancer. We can overcome 5-FU resistance in cancer cells by regulating thymidylate synthase by natural products (Coptidis rhizoma), HDAC inhibitors, mTOR inhibitors, Folate antagonists, and several other drugs which have been used in combination with TS inhibitors. This review is a compilation of different approaches reported for the regulation of thymidylate synthase to overcome resistance in colorectal cancer cells.

Epigenetic Approaches to Overcome Fluoropyrimidines Resistance in Solid Tumors

Simple Summary

Fluoropyrimidines represent the backbone of many combination chemotherapy regimens for the treatment of solid cancers but are still associated with toxicity and mechanisms of resistance. In this review, we focused on the epigenetic modifiers histone deacetylase inhibitors (HDACis) and on their ability to regulate specific genes and proteins involved in the fluoropyrimidine metabolism and resistance mechanisms. We presented emerging preclinical and clinical studies, highlighting the mechanisms by which HDACis can prevent/overcome the resistance and/or enhance the therapeutic efficacy of fluoropyrimidines, potentially reducing their toxicity, and ultimately improving the overall survival of cancer patients.

Abstract

Although fluoropyrimidines were introduced as anticancer agents over 60 years ago, they are still the backbone of many combination chemotherapy regimens for the treatment of solid cancers. Like other chemotherapeutic agents, the therapeutic efficacy of fluoropyrimidines can be affected by drug resistance and severe toxicities; thus, novel therapeutic approaches are required to potentiate their efficacy and overcome drug resistance. In the last 20 years, the deregulation of epigenetic mechanisms has been shown to contribute to cancer hallmarks. Histone modifications play an important role in directing the transcriptional machinery and therefore represent interesting druggable targets. In this review, we focused on histone deacetylase inhibitors (HDACis) that can increase antitumor efficacy and overcome resistance to fluoropyrimidines by targeting specific genes or proteins. Our preclinical data showed a strong synergistic interaction between HDACi and fluoropyrimidines in different cancer models, but the clinical studies did not seem to confirm these observations. Most likely, the introduction of increasingly complex preclinical models, both in vitro and in vivo, cannot recapitulate human complexity; however, our analysis of clinical studies revealed that most of them were designed without a mechanistic approach and, importantly, without careful patient selection.

A narrative review of genetic factors affecting fluoropyrimidine toxicity

OBJECTIVE

Our objective is to document progress in developing personalized therapy with fluoropyrimidine drugs (FPs) to improve outcomes for cancer patients and to identify areas requiring further investigation.

BACKGROUND

FPs including 5-fluorouracil (5-FU), are among the most widely used drugs for treating colorectal cancer (CRC) and other gastrointestinal (GI) malignancies. While FPs confer a survival benefit for CRC patients, serious systemic toxicities, including neutropenia, occur in ~30% of patients with lethality in 0.5-1% of patients. While serious systemic toxicities may occur in any patient, patients with polymorphisms in DPYD, which encodes the rate-limiting enzyme for pyrimidine degradation are at very high risk. Other genetic factors affecting risk for 5-FU toxicity, including miR-27a, are under investigation.

METHODS

Literature used to inform the text of this article was selected from PubMed.gov from the National Library of Medicine while regulatory documents were identified via Google search.

CONCLUSIONS

Clinical studies to date have validated four DPYD polymorphisms (DPYD*2A, DPYD*13, c.2846A>T, HapB3) associated with serious toxicities in patients treated with 5-FU. Genetic screening for these is being implemented in the Netherlands and the UK and has been shown to be a cost-effective way to improve outcomes. Factors other than DPYD polymorphisms (e.g., miR-27a, TYMS, ENOSF1, p53) also affect 5-FU toxicity. Functional testing for deficient pyrimidine catabolism {defined as [U] >16 ng/mL or [UH2]:[U] <10} is being implemented in France and has demonstrated utility in identifying patients with elevated risk for 5-FU toxicity. Therapeutic drug monitoring (TDM) from plasma levels of 5-FU during first cycle treatment also is being used to improve outcomes and pharmacokinetic-based dosing is being used to increase the percent of patients within optimal area under the curve (AUC) (18-28 mg*h/L) values. Patients maintained in the optimal AUC range experienced significantly reduced systemic toxicities. As understanding the genetic basis for increased risk of 5-FU toxicity becomes more refined, the development of functional-based methods to optimize treatment is likely to become more widespread.

A novel bioavailable curcumin-galactomannan complex modulates the genes responsible for the development of chronic diseases in mice: A RNA sequence analysis

BACKGROUND

Chronic diseases or non-communicable diseases are a major burden worldwide due to the lack of highly efficacious treatment modalities and the serious side effects associated with the available therapies.

PURPOSE/STUDY DESIGN

A novel self-emulsifying formulation of curcumin with fenugreek galactomannan hydrogel scaffold as a water-dispersible non-covalent curcumin-galactomannan molecular complex (curcumagalactomannosides, CGM) has shown better bioavailability than curcumin and can be used for the prevention and treatment of chronic diseases. However, the exact potential of this formulation has not been studied, which would pave the way for its use for the prevention and treatment of multiple chronic diseases.

METHODS

The whole transcriptome analysis (RNAseq) was used to identify differentially expressed genes (DEGs) in the liver tissues of mice treated with LPS to investigate the potential of CGM on the prevention and treatment of chronic diseases. Expression analysis using DESeq2 package, GO, and pathway analysis of the differentially expressed transcripts was performed using UniProtKB and KEGG-KAAS server.

RESULTS

The results showed that 559 genes differentially expressed between the liver tissue of control mice and CGM treated mice (100 mg/kg b.wt. for 14 days), with adjusted p-value below 0.05, of which 318 genes were significantly upregulated and 241 were downregulated. Further analysis showed that 33 genes which were upregulated (log2FC > 8) in the disease conditions were significantly downregulated, and 32 genes which were downregulated (log2FC < -8) in the disease conditions were significantly upregulated after the treatment with CGM.

CONCLUSION

Overall, our study showed CGM has high potential in the prevention and treatment of multiple chronic diseases.

DPYD Exome, mRNA Expression and Uracil Levels in Early Severe Toxicity to Fluoropyrimidines: An Extreme Phenotype Approach

Dihydropyrimidine dehydrogenase deficiency is a major cause of severe fluoropyrimidine-induced toxicity and could lead to interruption of chemotherapy or life-threatening adverse reactions. This study aimed to characterize the DPYD exon sequence, mRNA expression and in vivo DPD activity by plasma uracil concentration. It was carried out in two groups of patients with extreme phenotypes (toxicity versus control) newly treated with a fluoropyrimidine, during the first three cycles of treatment. A novel nonsense gene variant (c.2197insA) was most likely responsible for fluoropyrimidine-induced toxicity in one patient, while neither DPYD mRNA expression nor plasma uracil concentration was globally associated with early toxicity. Our present work may help improve pharmacogenetic testing to avoid severe and undesirable adverse reactions to fluoropyrimidine treatment and it also supports the idea of looking beyond DPYD.

Auger electron therapy of glioblastoma using [125I]5-iodo-2'-deoxyuridine and concomitant chemotherapy - Evaluation of a potential treatment strategy

INTRODUCTION

Treatment of glioblastomas (GBM) using the Auger electron emitting compound [125I]5-Iodo-2'-deoxyuridine ([125I]I-UdR), combined with the thymidylate synthase inhibitor methotrexate (MTX) and concomitant chemotherapy with temozolomide (TMZ) has recently shown very promising therapeutic effects in vitro and in vivo in animals. The aim of the current study was to investigate if the therapeutic effects of this multimodal treatment strategy could be further increased by the thymidylate synthase inhibitor, 5-fluoro-2'-deoxyuridine (F-UdR), in comparison to MTX, and if the co-treatment should be given in a neoadjuvant or adjuvant setting.

METHODS

A patient-derived GBM cancer stem cell (CSC)-enriched cell line, grown as neurospheres, was employed to evaluate DNA-incorporation of [125I]I-UdR, determined by a DNA precipitation assay, using either pre-treatment or co-treatment with MTX or F-UdR. The therapeutic effects in the CSC-enriched cell line after exposure to various combinations of MTX, F-UdR, TMZ and [125I]I-UdR were also investigated by a CellTiter-Blue assay.

RESULTS

The highest general increase in [125I]I-UdR incorporation was observed with F-UdR co-treatment, which resulted in approx. 2.5-fold increase in the DNA-associated activity. Also the cell viability was significantly decreased when F-UdR was combined with [125I]I-UdR compared to [125I]I-UdR alone at all activity concentrations tested. MTX was redundant when combined with 400 and 500 Bq/ml [125I]I-UdR. TMZ was effective in combination with either [125I]I-UdR alone or with both thymidylate synthase inhibitors combined with 50-100 Bq/ml [125I]I-UdR.

CONCLUSIONS

Overall, our study revealed a higher incorporation and therapeutic effect of [125I]I-UdR when GBM cells were co-treated with F-UdR compared to MTX. The therapeutic effects were further increased when TMZ was combined with [125I]I-UdR in combination with the thymidylate synthase inhibitors.

ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE

Auger electron therapy in combination with thymidylate synthase inhibition and concomitant chemotherapy has the potential to become a future therapeutic treatment option for patients with glioblastoma.

Intraperitoneal Chemotherapy for Peritoneal Metastases: Technical Innovations, Preclinical and Clinical Advances and Future Perspectives

(1) Background: Tumors of the peritoneal serosa are called peritoneal carcinosis. Their origin may be primary by primitive involvement of the peritoneum (peritoneal pseudomyxoma, peritoneal mesothelioma, etc.). This damage to the peritoneum can also be a consequence of the dissipation of cancers-in particular, digestive (stomach, pancreas, colorectal, appendix) and gynecological (ovaries) ones in the form of metastases. The aim of the treatment is a maximal reduction of the macroscopic disease called "cytoreduction" in combination with hyperthermic intra-abdominal chemotherapy to treat residual microscopic lesions. (2) Methods: In this narrative review, we fundamentally synthetize the evolution of this process over time and its impact on clinical applications. (3) Results: Over the last past decade, different evolutions concerning both delivery modes and conditions concerning hyperthermic intra-abdominal chemotherapy have been realized. (4) Conclusion: The final objective of these evolutions is the improvement of the global and recurrence-free survival of primary and secondary malignant peritoneal pathologies. However, more large randomized controlled trials are needed to demonstrate the efficacy of such treatments with the help of molecular biology and genetics.

Hydroxychavicol, a polyphenol from Piper betle leaf extract, induces cell cycle arrest and apoptosis in TP53-resistant HT-29 colon cancer cells

This study aims to elucidate the antiproliferative mechanism of hydroxychavicol (HC). Its effects on cell cycle, apoptosis, and the expression of c-Jun N-terminal kinase (JNK) and P38 mitogen-activated protein kinase (MAPK) in HT-29 colon cancer cells were investigated. HC was isolated from Piper betle leaf (PBL) and verified by high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), and gas chromatography-mass spectrometry (GC-MS). The cytotoxic effects of the standard drug 5-fluorouracil (5-FU), PBL water extract, and HC on HT-29 cells were measured after 24, 48, and 72 h of treatment. Cell cycle and apoptosis modulation by 5-FU and HC treatments were investigated up to 30 h. Changes in phosphorylated JNK (pJNK) and P38 (pP38) MAPK expression were observed up to 18 h. The half maximal inhibitory concentration (IC₅₀) values of HC (30 μg/mL) and PBL water extract (380 μg/mL) were achieved at 24 h, whereas the IC₅₀ of 5-FU (50 μmol/L) was obtained at 72 h. Cell cycle arrest at the G₀/G₁ phase in HC-treated cells was observed from 12 h onwards. Higher apoptotic cell death in HC-treated cells compared to 5-FU-treated cells (P<0.05) was observed. High expression of pJNK and pP38 MAPK was observed at 12 h in HC-treated cells, but not in 5-FU-treated HT-29 cells (P<0.05). It is concluded that HC induces cell cycle arrest and apoptosis of HT-29 cells, with these actions possibly mediated by JNK and P38 MAPK.

Application of smart solid lipid nanoparticles to enhance the efficacy of 5-fluorouracil in the treatment of colorectal cancer

5-Fluorouracil (5-FU) is a standard treatment option for colorectal cancer (CRC) but its rapid metabolism and systemic instability (short half-life) has hindered its therapeutic efficacy. The objective of this study was to develop a novel drug delivery system, solid lipid nanoparticle (SLN), capable of delivering high payload of 5-FU to treat CRC. The rational was to improve 5FU-nanocarrier compatibility and therapeutic efficacy. The SLN-loaded 5-FU was developed by utilizing a Strategic and unique Method to Advance and Refine the Treatment (SMART) of CRC through hot and cold homogenization approach. The SLN was made of unique PEGylated lipids and combination of the surfactants. Cytotoxicity studies, clonogenic assay, flow cytometry and confocal imaging were conducted to evaluate the effectiveness and cellular uptake of 5FU-SLN4 in HCT-116 cancer cells. Pharmacokinetic (PK) parameters and receptor expressions were determined while tumor efficacy studies were conducted on mouse bearing subcutaneous HCT-116 cancer. Among the all the formulations, 5FU-SLN4 was the most effective with particle size of was 263 ± 3 nm, zeta potential was 0.1 ± 0.02 and entrapment efficiency of 81 ± 10%. The IC50 value of 5FU-SLN4 (7.4 ± 0.02 µM) was 2.3 fold low compared with 5-FU (17.7 ± 0.03 µM). For tumor efficacy studies, 5FU-SLN4 significantly inhibited tumor growth in comparison to 5-FU while area-under plasma concentration-time curve (AUC) of 5FU-SLN4 was 3.6 fold high compared with 5-FU. HER2 receptors expression were markedly reduced in 5-FU-SLN4 treated mice compared with 5FU and liver and kidney tissues showed no toxicity at dose of 20 mg/kg. 5FU-SLN4 was highly cytotoxic against HCT-116 cells and significantly inhibited subcutaneous tumor growth in mice compared with 5-FU. This emphasizes the significance of developing a smart nano-delivery system to optimize the delivery efficiency of anticancer drugs to tumors.

Pharmacogenomics of 5-fluorouracil in colorectal cancer: review and update

BACKGROUND

Colorectal cancer (CRC) is a disease with high morbidity and mortality rates. 5-fluorouracil (5-FU) is the first-line recommended drug for chemotherapy in patients with CRC, and it has a good effect on a variety of other solid tumors as well. Unfortunately, however, due to the emergence of drug resistance the effectiveness of treatment may be greatly reduced. In the past decade, major progress has been made in the field of 5-FU drug resistance in terms of molecular mechanisms, pre-clinical (animal) models and clinical trials.

CONCLUSIONS

In this article we systematically review and update current knowledge on 5-FU pharmacogenomics related to drug uptake and activation, the expression and activity of target enzymes (DPD, TS and MTHFR) and key signaling pathways in CRC. Furthermore, a summary of drug combination strategies aimed at targeting specific genes and/or pathways to reverse 5-FU resistance is provided. Based on this, we suggest that causal relationships between genes, pathways and drug sensitivity should be systematically considered from a multidimensional perspective. In the design of research methods, emerging technologies such as CRISPR-Cas, TALENS and patient-derived xenograft models should be applied as far as possible to improve the accuracy of clinically relevant results.

DPD status and fluoropyrimidines-based treatment: high activity matters too

Background

Dihydropyrimidine dehydrogenase (DPD) status is an indicator of a marked risk for toxicity following fluoropyrimidine (FP)-based chemotherapy. This notion is well-established for low DPD status but little is known about the clinical impact of high DPD activity. This study examined the possible link between high intrinsic lymphocytic DPD activity and overall survival, progression free survival and response to FP-based treatment in patients treated in our institution.

Methods

Lymphocytic DPD activity was assessed in a group of 136 patients receiving FP-based chemotherapy from 2004 to 2016. There were 105 digestive (77.2%), 24 breast (17.6%) and 7 head and neck cancers (5.2%). Cox or logistic regression models were applied with adjustment on all confounding factors that could modify OS, PFS or response. All models were stratified on the three cancer locations. A cut-off for DPD activity was assessed graphically and analytically.

Results

An optimal cut-off for DPD activity at 0.30 nmol/min/mg protein was identified as the best value for discriminating survivals and response. In multivariate analysis, individual lymphocytic DPD activity was significantly related to overall survival (p = 0.013; HR: 3.35 CI95%[1.27–8.86]), progression-free survival (p < 0.001; HR: 3.15 CI95%[1.75–5.66]) and response rate (p = 0.033; HR: 0.33 CI95%[0.12–0.92]) with a marked detrimental effect associated with high DPD activity.

Conclusions

DPD status screening should result in a two-pronged approach with FP dose reduction in case of low intrinsic DPD and, inversely, an increased FP dose for high intrinsic DPD. In a context of personalized FP-based treatment, this innovative strategy needs to be prospectively validated.

β-Elemene Reverses the Resistance of p53-Deficient Colorectal Cancer Cells to 5-Fluorouracil by Inducing Pro-death Autophagy and Cyclin D3-Dependent Cycle Arrest

Objective

Colorectal cancer is a malignant tumor of the digestive system with high morbidity and mortality. 5-fluorouracil remains a widely used chemotherapeutic drug in the treatment of advanced colorectal cancer, but chemotherapy drugs are prone to develop drug resistance, p53 deletion or mutation is an important reason for the resistance of colorectal cancer cells to 5-fluorouracil. β-elemene has been proved to have the potential of reverse chemotherapy drug resistance, but the mechanism is unknown. This study aimed to investigate the effect of β-elemene to 5-fluorouracil in drug-resistant p53-deficient colorectal cancer cells HCT116p53^–/–, and determine the possible molecular mechanism of β-elemene to reverse 5-fluorouracil resistance.

Methods

The effect of β-elemene on HCT116p53^–/– cell activity was detected by Cell counting Kit-8. Cell proliferation was detected by monoclonal plate. The apoptosis was detected by flow cytometry and western blot. The autophagy was detected by western blot, immunofluorescence and transmission electron microscope. Determine the role of Cyclin-related protein Cyclin D3 in β-elemene reversing the resistance of HCT116p53^–/– to 5-fluorouracil was detected by overexpression of Cyclin D3. The effect of β-elemene on the tumorigenic ability of p53-deficient colorectal cancer cells was detected establishing HCT116p53^–/– all line xenograft model.

Results

For p53 wildtype colorectal cancer cells, β-elemene could augment the sensitivity of 5-fluorouracil, for p53-deficient colorectal cancer cells, β-elemene significantly inhibited cell proliferation in a concentration-dependent manner, and reversed the resistance of HCT116p53^–/– to 5-fluorouracil by inducing pro-death autophagy and Cyclin D3-dependent cycle arrest.

Conclusion

β-elemene enhances the sensitivity of p53 wild-type cells to 5-fluorouracil, β-elemene can reverse the resistance of HCT116p53^–/– to 5-fluorouracil by inducing pro-death autophagy and Cyclin D3-dependent cycle arrest in p53-deficient colorectal cancer, which will provide a new method for the treatment of p53 deletion colorectal cancer patients.

17-allylamino-17-demethoxygeldanamycin impeded chemotherapy through antioxidant activation via reducing reactive oxygen species-induced cell death

Hyperthermia enhances the anticancer effects of thymidylate synthase (TYMS) inhibitors (raltitrexed, RTX) and improves the precise biochemical mechanisms partially through enhancement of intracellular drug absorption. Recent research focuses on the potential anticancer drug target Heat Shock Protein 90 (HSP90), which could increase the sensitivity of cancer cells to TYMS inhibitors; however, with different HSP90 inhibitors, several research studies finally showed a poor efficacy in preclinical or clinical research. Here, we showed that 17-allylamino-17-demethoxygeldanamycin (17-AAG, HSP90 inhibitor) affects the efficacy of chemotherapy through antioxidant activation-induced resistance. In this study, we found that RTX, alone or in combination with hyperthermia, triggers reactive oxygen species (ROS) exposure and thus induces cell death. Also, the addition of hyperthermia showed more ROS exposure and function. The pharmacologic inhibition of HSP90 reversed the effects of chemotherapeutical treatments, while the overexpression of HSP90 showed no relation with these effects, which demonstrated that dysregulation of HSP90 might have a significant impact on chemotherapeutic treatments. The addition of 17-AAG increased the activation of antioxidant with increased antioxidant enzymes, thus affecting the RTX efficacy.

Drug resistance related to aberrant glycosylation in colorectal cancer

Colorectal cancer (CRC) is the fourth leading cause of cancer-related deaths in the world. Drug resistance of tumour cells remains the main challenge toward curative treatments efficiency. Several epidemiologic studies link emergence and recurrence of this cancer to metabolic disorders. Glycosylation that modifies more than 80% of human proteins is one of the most widepread nutrient-sensitive post-translational modifications. Aberrant glycosylation participates in the development and progression of cancer. Thus, some of these glycan changes like carbohydrate antigen CA 19-9 (sialyl Lewis a, sLea) or those found on carcinoembryonic antigen (CEA) are already used as clinical biomarkers to detect and monitor CRC. The current review highlights emerging evidences accumulated mainly during the last decade that establish the role played by altered glycosylations in CRC drug resistance mechanisms that induce resistance to apoptosis and activation of signaling pathways, alter drug absorption and metabolism, and led to stemness acquisition. Knowledge in this field of investigation could aid to the development of better therapeutic approaches with new predictive biomarkers and targets tied in with adapted diet.