Oral Administration of Cancer Vaccines: Challenges and Future Perspectives.

Cancer vaccines, a burgeoning strategy in cancer treatment, are exploring innovative administration routes to enhance patient and medical staff experiences, as well as immunological outcomes. Among these, oral administration has surfaced as a particularly noteworthy approach, which is attributed to its capacity to ignite both humoral and cellular immune responses at systemic and mucosal tiers, thereby potentially bolstering vaccine efficacy comprehensively and durably. Notwithstanding this, the deployment of vaccines through the oral route in a clinical context is impeded by multifaceted challenges, predominantly stemming from the intricacy of orchestrating effective oral immunogenicity and necessitating strategic navigation through gastrointestinal barriers. Based on the immunogenicity of the gastrointestinal tract, this review critically analyses the challenges and recent advances and provides insights into the future development of oral cancer vaccines.

rs4143815-PDL1, a New Potential Immunogenetic Biomarker of Biochemical Recurrence in Locally Advanced Prostate Cancer after Radiotherapy.

Up to 30-50% of patients with locally advanced prostate cancer (PCa) undergoing radiotherapy (RT) experience biochemical recurrence (BCR). The immune system affects the RT response. Immunogenetics could define new biomarkers for personalization of PCa patients' treatment. The aim of this study is to define the immunogenetic biomarkers of 10 year BCR (primary aim), 10 year overall survival (OS) and 5 year BCR (secondary aims). In this mono-institutional retrospective study, 549 Caucasian patients (a discovery set n = 418; a replication set n = 131) were affected by locally advanced PCa and homogeneously treated with RT. In the training set, associations were made between 447 SNPs in 77 genes of the immune system; and 10 year BCR and 10 year OS were tested through a multivariate Cox proportional hazard model. Significant SNPs (p-value < 0.05, q-value < 0.15) were analyzed in the replication set. Replicated SNPs were tested for 5 year BCR in both sets of patients. A polymorphism in the PDL1 gene (rs4143815) was the unique potential genetic variant of 10 year BCR (training set: p = 0.003, HR (95% CI) = 0.58 (0.41-0.83); replication set: p = 0.063, HR (95% CI) = 0.52 (0.26-1.04)) that was significantly associated with 5 year BCR (training set: p = 0.009, HR (95% CI) = 0.59 (0.40-0.88); replication set: p = 0.036, HR (95% CI) = 0.39 (0.16-0.94)). No biomarkers of OS were replicated. rs4143815-PDL1 arose as a new immunogenetic biomarker of BCR in PCa, giving new insights into the RT/immune system interaction, which could be potentially useful in new approaches using anti-PDL1 therapies for PCa.

The Genotype for DPYD Risk Variants in Patients With Colorectal Cancer and the Related Toxicity Management Costs in Clinical Practice.

Lack of information on the clinical utility of preemptive DPYD screening before fluoropyrimidine treatment is a major barrier preventing its use in clinical practice. This study aimed to define the association between DPYD variants and fluoropyrimidine-related toxicity management costs. A cost analysis was conducted on the toxicities experienced by 550 patients with colorectal cancer treated with fluoropyrimidine-based chemotherapy. Genotyping for DPYD*2A, DPYD*13, DPYDc. 2846A>T, DPYD-HapB3, and UGT1A1*28 was done retrospectively and did not affect patients' treatments. Carriers of at least one DPYD variant experienced higher toxicity management costs (€2,972; 95% confidence interval (CI), €2,456-€3,505) than noncarriers (€825; 95% CI, €785-€864) (P < 0.0001) and had a higher risk for toxicity requiring hospitalization (odds ratio, 4.14; 95% CI, 1.87-9.14). In patients receiving fluoropyrimidine/irinotecan, the incremental cost between DPYD variant and UGT1A1*28/*28 carriers and noncarriers was €2,975. This study suggests that the toxicity management costs during fluoropyrimidine-based therapy are associated with DPYD and UGT1A1*28 variants and supports the utility of genotyping.

Identification of Novel Somatic TP53 Mutations in Patients with High-Grade Serous Ovarian Cancer (HGSOC) Using Next-Generation Sequencing (NGS).

Somatic mutations in TP53 are a hallmark of high-grade serous ovarian cancer (HGSOC), although their prognostic and predictive value as markers is not well defined. Next-generation sequencing (NGS) can identify novel mutations with high sensitivity, that may be repurposed as potential druggable anti-cancer targets and aid in therapeutic decisions. Here, a commercial NGS cancer panel comprising 26 genes, including TP53, was used to identify new genetic markers of platinum resistance and patient prognosis in a retrospective set of patients diagnosed with epithelial ovarian cancer. Six novel TP53 somatic mutations in untreated tumors from six distinct patients diagnosed with HGSOC were identified: TP53 c.728_739delTGGGCGGCATGA (p.Met243_Met247del, in-frame insertion or deletion (INDEL); TP53 c.795_809delGGGACGGAACAGCTT (p.Gly266_Phe270del, in-frame INDEL); TP53 c.826_827GC>AT (p.Ala276Ile, missense); TP53 c.1022insT (p.Arg342Profs*5, frameshift INDEL); TP53 c.1180delT (p.Ter394Aspfs*28, frameshift INDEL); and TP53 c.573insT (p.Gln192Serfs*17, frameshift INDEL). Novel TP53 variants were validated by classical sequencing methods and their impact on protein expression in tumors explored by immunohistochemistry. Further insights into the potential functional effect of the mutations were obtained by different in silico approaches, bioinformatics tools, and structural modeling. This discovery of previously unreported TP53 somatic mutations provides an opportunity to translate NGS technology into personalized medicine and identify new potential targets for therapeutic applications.

Identification of proteins associated to multi-drug resistance in LoVo human colon cancer cells.

Multi-drug resistance (MDR) limits the effectiveness of chemotherapy. P-glycoprotein encoded by the MDR1 gene, is known to be implicated in MDR phenotype, but other factors could be determinant in MDR. The aim of this study was to investigate new molecular factors potentially associated with the MDR phenotype using a proteomic approach. Two dimensional fluorescence difference gel electrophoresis (2D-DIGE) and MALDI-TOF peptide mass fingerprinting were used to determine differentially expressed proteins between LoVo human colon carcinoma cell line and one of its MDR sublines (LoVo-R1). Thirty-four differentially expressed proteins were identified. They were classified into five groups based on their biological functions: i) proteins involved in energy request pathways, ii) in detoxification pathways, iii) in cell survival activity, iv) in drug transport and v) in chaperone functions. Among these proteins, endothelin 1 and proteasome subunit beta2 regulations were validated by immunofluorescence and Western blotting, respectively, showing complete consistency with 2D-DIGE results. In conclusion, the proteomic approach indicates that multiple mechanisms are simultaneously involved in MDR. These might be useful in the search for new forms of interventional therapeutic approaches for MDR reversal.

Prevalence of methylenetetrahydrofolate reductase polymorphisms in young patients with inflammatory bowel disease.

Inflammatory bowel disease (IBD) has been related to mutations of methylenetetrahydrofolate reductase (MTHFR), a critical enzyme in the metabolism of folate and methionine, both of which are important factors in DNA methylation and synthesis. A mutated MTHFR genotype was associated with increased toxicity of methotrexate treatment. The objective of this study was to verify, in a population of young patients with IBD, the presence of an association among mutations in the MTHFR gene, the incidence of IBD, and the risk of adverse events during the treatment with thiopurines azathioprine (AZA) or 6-mercaptopurine (6MP). Ninety-two patients with IBD were enrolled; 63 were treated with thiopurines; patients and 130 controls were genotyped for MTHFR mutations by PCR-based methods. The incidence of mutations in the MTHFR gene was not different between patients with IBD and control subjects; the mutated genotype was not associated with an increased risk of toxicity during thiopurine treatment.

Thymidylate synthetase mRNA levels are increased in liver metastases of colorectal cancer patients resistant to fluoropyrimidine-based chemotherapy.

BACKGROUND: Fluoropyrimidines such as 5-fluorouracil (5-FU) and 5-fluoro-2'deoxyuridine (FUDR) are among the most effective chemotherapeutic agents for treatment of metastatic colorectal cancer (CRC). Increased expression of thymidylate synthetase (TS) in CRC metastases has been proposed to be an important mechanism of resistance to fluoropyrimidine-based chemotherapy. METHODS: The present study investigated whether TS mRNA levels in liver metastases of 20 CRC patients before treatment with FUDR by hepatic arterial infusion (HAI) correlated with frequency of clinical response or survival duration. RESULTS: Median survival duration of patients with TS mRNA levels above and below the median was 15 and 18 months, respectively (p > 0.05). Clinical response was achieved in 40% of patients with low TS mRNA levels, but in only 20% of patients with high TS mRNA levels (p = 0.01). TS mRNA levels were also measured for liver metastases of 7 of the patients that did not achieve a clinical response. A statistically significant increase in expression of TS mRNA was observed for liver metastases resistant to chemotherapy (21 +/- 14) in comparison to liver metastases of the same patients before chemotherapy (8 +/- 4) (p = 0.03). CONCLUSION: This is the first report to demonstrate increased TS expression in liver metastases from CRC patients resistant to fluoropyrimidine based chemotherapy. These findings are consistent with previous studies indicating that increased TS expression is associated with resistance to fluoropyrimidine-based chemotherapy.

Methylenetetrahydrofolate reductase 677 C-->T polymorphism and risk of proximal colon cancer in north Italy.

PURPOSE: Gene silencing by hypermethylation plays an important role in proximal colon carcinogenesis. Conversely, DNA hypomethylation has been associated with distal colon cancer (CLC). Methylenetetrahydrofolate reductase (MTHFR) catalyzes the conversion of 5',10'-methylenetetrahydrofolate to 5'-methyl tetrahydrofolate, which serves as methyl donor in the remethylation of homocysteine to methionine. A common MTHFR 677 C-->T polymorphism is characterized by reduced catalytic activity, which affects methionine synthesis and DNA methylation. The aim of the study was to investigate the role of MTHFR 677 C-->T gene polymorphism in the tumorigenesis of proximal and distal CLC in a monoinstitutional group of patients in North Italy. EXPERIMENTAL DESIGN: One-hundred thirty four consecutive proximal and 142 consecutive distal CLC patients, and 279 control subjects without cancer were genotyped for MTHFR using PCR-restriction fragment-length polymorphism analysis. RESULTS: The prevalence of the 677 TT genotype was significantly (P = 0.005) lower in patients with proximal tumors (10 of 134, 7%) than in subjects with distal tumors (28 of 142, 20%). Case/control approach indicated that individuals homozygous for the 677 TT allele had a significantly reduced risk (2.8-fold) (adjusted odds ratio, 0.36; 95% confidence intervals, 0.14-0.91) of developing proximal CLC compared with those harboring the wild-type or heterozygous genotype (677 CC or 677 CT). No significant association between CLC risk and TT genotype was observed in patients with distal tumors (odds ratio, 1.01; 95% confidence interval, 0.48-2.14). CONCLUSIONS: Our findings support a role for MTHFR 677 TT genotype in reducing proximal CLC risk in North Italy.

Effect of methylenetetrahydrofolate reductase 677C-->T polymorphism on toxicity and homocysteine plasma level after chronic methotrexate treatment of ovarian cancer patients.

MTHFR is a critical enzyme that regulates the metabolism of folate and methionine, both of which are important factors in DNA methylation and synthesis. Subjects with the 677C-->T variant have impaired remethylation of Hcy to methionine that could determine hyperhomocysteinemia. Remethylation of Hcy into methionine and DNA methylation are also affected by MTX treatment. Thus, a combined effect between MTX and reduced activity of the MTHFR 677C-->T polymorphism could occur, leading to toxicity. In a clinical trial, 43 ovarian cancer patients were treated with low doses of MTX. During MTX therapy, 12 patients (27.9%) developed G3/4 WHO toxicity. In these 12 patients, we observed 6 G3/4 thrombocytopenias, 1 G3 neutropenia, 1 G3 anemia, 9 G3 mucositis cases and 1 G4 mucositis case. A significant association was observed between toxicity and TT MTHFR 677 genotype (p < 0.0001). G3/4 toxicity occurred in 10 of 13 (77%), 1 of 17 (6%) and 1 of 13 (8%) patients with the TT, CT and CC MTHFR genotypes, respectively. According to the logistic regression model, patients with the TT genotype had a relative risk of 42.0 (95% CI 4.2-418.6) of developing G3/4 toxicity compared to patients with the CC and CT genotypes. Patients with the TT genotype had Hcy plasma levels after MTX therapy significantly (p = 0.0001) higher than basal levels (mean +/- SD = 16.71 +/- 4.72 vs. 12.48 +/- 3.57 micromol/l); moreover, they also had higher Hcy plasma levels after MTX than patients with other MTHFR 677 genotypes (CC mean +/- SD = 9.87 +/- 3.61 micromol/l and CT mean +/- SD = 11.48 +/- 3.13 micromol/l). Finally, significant associations were observed between G3/4 WHO toxicity and higher Hcy plasma levels after MTX treatment (p = 0.0004). In conclusion, our data suggest that the TT MTHFR 677 genotype is associated with marked MTX-induced hyperhomocysteinemia and could represent a pharmacogenetic marker for toxicity after chronic treatment with low doses of MTX.