Treatment of patients with carcinomas in advanced stages with 5-fluorouracil, folinic acid and pyridoxine in tandem.

The effect of high-dose pyridoxine (PN) on activity of 5-fluorouracil (FUra) and folinic acid (FA)-containing regimens was studied in 50 patients including 14 with digestive tract, and 36 with breast carcinomas (BC) in advanced stages with poor prognostic characteristics. Patients with colorectal, and pancreas adenocarcinoma received oxaliplatin, irinotecan, FUra, FA (Folfirinox), and patients with squamous cell carcinoma of the esophagus had paclitaxel, carboplatin, FUra, FA (TCbF). Patients with BC received AVCF (doxorubicin, vinorelbine, cyclophosphamide, FUra, FA) followed by TCbF or TCbF only, and patients who overexpressed HER2 received TCbF plus trastuzumab and pertuzumab. PN (1000-3000 mg/day iv) preceded each administration of FUra and FA. 47 patients (94%) responded, including 16 (32%) with CR. Median tumor reduction was 93%. Median event-free survival (EFS) was 37.7 months. The 25 patients with tumor shrinkage ≥ 91% had EFS of 52% from 42 months onwards. Unexpected toxicity did not occur. PN enhances potency of chemotherapy regimens comprising FUra and FA.

Progressive erythrocytosis under lenvatinib treatment in patients with advanced hepatocellular carcinoma.

PURPOSE: This manuscript reports on the occurrence of early and frequent erythrocytosis in advanced hepatocellular carcinoma (HCC) patients treated with lenvatinib. METHODS: A cohort of 23 patients with advanced HCC, treated with this antiangiogenic drug for at least one month, was retrospectively analyzed. RESULTS: These patients (82.7% men, median age 58.3, cirrhosis in 60.8%) were treated between October 2019 and September 2020 with lenvatinib, as first-line systemic therapy for 82.6% of them. For 20 patients (87%), an early and significant increase in hemoglobin (Hb) level, up to 1.41 g/dL (p < 0.001) was reported and remained elevated. Ten patients (43.5%), all men, reached erythrocytosis (Hb > 16.5 g/dL), 7 were treated with low-dose aspirin for primary thromboprophylaxis and 2 needed phlebotomy. None underwent thromboembolic complications. A significant Hb decrease was observed after treatment discontinuation (p < 0.05). Erythropoietin (EPO) serum levels also increased, which was attributed to HCC after immunostaining for EPO in liver biopsies. The Naranjo adverse drug reaction probability scale documented the relationship between erythrocytosis and lenvatinib and regression at treatment discontinuation. Erythrocytosis was hypothesized to be a class effect of anti-VEGF therapies, the magnitude of which might depend on the IC50 value of each molecule. CONCLUSION: This report documents the frequent occurrence of erythrocytosis during lenvatinib treatment for advanced HCC, likely secondary to EPO secretion by tumor cells through the antiangiogenic activity levatinib. An early and close monitoring of hematologic parameters is, thus, recommended, together with thromboprophylaxis by low-dose aspirin and phlebotomy in case of symptomatic erythrocytosis.

Pharmacologic modulation of 5-fluorouracil by folinic acid and pyridoxine for treatment of patients with advanced breast carcinoma.

High concentration pyridoxal 5'-phosphate, the cofactor of vitamin B6, potentiates cytotoxicity in cancer cells exposed to 5-fluorouracil (FUra) and folinic acid (FA). We studied the effect of high-dose pyridoxine on antitumor activity of regimens comprising FUra and FA in 27 advanced breast carcinoma patients. Of 18 previously untreated patients, 12 had tumors that did not overexpress HER2 (Group I), and 6 that overexpressed HER2 (Group II). Nine patients (Group III) had prior chemotherapy. Group I received AVCF (doxorubicin, vinorelbine, cyclophosphamide, FUra, FA) or FAC (doxorubicin, cyclophosphamide, FUra, FA) followed by TCbF (paclitaxel carboplatin, FUra, FA). Groups II, and III received TCbF. Pyridoxine iv (1000-3000 mg/day) preceded each FA and FUra. Group II also received trastuzumab and pertuzumab. 26 patients responded. Three patients in Group I had CRs and 9 had PRs with 62-98% reduction rates; 4 patients in Group II had CRs and 2 had PRs with 98% reduction. Of 7 measurable patients in Group III, 2 attained CRs, and 5 had PRs with 81-94% reduction rates. Median time to response was 3.4 months. Unexpected toxicity did not occur. This pilot study suggests that high-dose vitamin B6 enhances antitumor potency of regimens comprising FUra and FA.

Pharmacologic modulation of 5-fluorouracil by folinic acid and high-dose pyridoxine for treatment of patients with digestive tract carcinomas.

Supplementation of cancer cells exposed to 5-fluorouracil (FUra) and folinic acid (FA) with high concentration pyridoxal 5'-phosphate, the cofactor of vitamin B6, potentiates the cytotoxicity of FUra in a synergistic interaction mode. We report a pilot study in 13 patients with previously untreated advanced carcinoma of the digestive tract to assess the impact of high-dose pyridoxine (PN) on the antitumor activity of regimens comprising FUra and FA. Five patients had colorectal adenocarcinoma (CRC); 5 had pancreas adenocarcinoma (PC); and 3 had squamous cell carcinoma of the esophagus (EC). Patients with CRC and with PC received oxaliplatin, irinotecan, FUra and FA, and patients with EC had paclitaxel, carboplatin, FUra and FA. PN iv from 1000 to 3000 mg/day preceded each administration of FA and FUra. Eleven patients responded. Two patients with CRC attained CRs and 3 had PRs with reduction rates ≥ 78%. Two patients with PC attained CRs, and 2 had PRs with reduction rates ≥ 79%. Responders experienced disappearance of most metastases. Of 3 patients with EC, 2 attained CRs. Median time to attain a response was 3 months. Unexpected toxicity did not occur. Results suggest that high-dose vitamin B6 enhances antitumor potency of regimens comprising FUra and FA.

Anti-Programmed death-1 therapy in advanced hepatocellular carcinoma: A real-world experience.

Nivolumab is an effective and safe treatment in HCC.

Effects in Cancer Cells of the Recombinant l-Methionine Gamma-Lyase from Brevibacterium aurantiacum. Encapsulation in Human Erythrocytes for Sustained l-Methionine Elimination.

Methionine deprivation induces growth arrest and death of cancer cells. To eliminate l-methionine we produced, purified, and characterized the recombinant pyridoxal 5'-phosphate (PLP)-dependent l-methionine γ-lyase (MGL)- BL929 from the cheese-ripening Brevibacterium aurantiacum Transformation of an Escherichia coli strain with the gene BL929 from B. aurantiacum optimized for E. coli expression led to production of the MGL-BL929. Elimination of l-methionine and cytotoxicity in vitro were assessed, and methylation-sensitive epigenetics was explored for changes resulting from exposure of cancer cells to the enzyme. A bioreactor was built by encapsulation of the protein in human erythrocytes to achieve sustained elimination of l-methionine in extracellular fluids. Catalysis was limited to α,γ-elimination of l-methionine and l-homocysteine. The enzyme had no activity on other sulfur-containing amino acids. Enzyme activity decreased in presence of serum albumin or plasma resulting from reduction of PLP availability. Elimination of l-methionine induced cytotoxicity on a vast panel of human cancer cell lines and spared normal cells. Exposure of colorectal carcinoma cells to the MGL-BL929 reduced methyl-CpG levels of hypermethylated gene promoters including that of CDKN2A, whose mRNA expression was increased, together with a decrease in global histone H3 dimethyl lysine 9. The MGL-erythrocyte bioreactor durably preserves enzyme activity in vitro and strongly eliminates l-methionine from medium.

Enhancement of 5-Fluorouracil Cytotoxicity by Pyridoxal 5'-Phosphate and Folinic Acid in Tandem.

The current study originates from the assumption that, in tumors, levels of naturally occurring pyridoxal 5'-phosphate (PLP) are too small to allow conversion of tetra hydro pteroylglutamate (H4PteGlu) into methylene tetra hydro pteroylglutamate (CH2-H4PteGlu) in amounts required to improve inhibition of thymidylate synthase by 5-fluorouracil (FUra) through ternary complex stabilization. The hypothesis relates to the low affinity for cofactor of the PLP-dependent serine hydroxymethyl transferase (SHMT), the enzyme that catalyzes formation of CH2-H4PteGlu by transfer of the Cß of serine to H4PteGlu. Intracellular concentrations of PLP are smaller than the dissociation constant of SHMT for cofactor, which suggests that enzyme activity should be sensitive to PLP level changes. Three cancer cell lines were supplemented with PLP to investigate the influence of this cofactor on FUra cytotoxicity. Cells were exposed to FUra, FUra and folinic acid (FA), FUra and PLP, and FUra combined with both FA and PLP. The median-effect principle for concentration-effect analysis and combination indices were used to determine interactions on cytotoxicity. FUra cytotoxicity in vitro was enhanced by FA and PLP in tandem. Synergistic cytotoxic interaction of FUra with FA and PLP was demonstrated in HT29 and L1210 cells. Summation was found in HCT116 cells. Parenteral pyridoxamine was administered in mice to explore erythrocyte production of PLP in vivo. Cofactor attained levels in the range of the KD for binding to SHMT, and it was rapidly cleared from cells. Pharmacokinetics of pyridoxamine suggests that modulation of FUra by vitamin B6 could be achieved in vivo.

Very late recurrence of Diethylstilbestrol - related clear cell carcinoma of the cervix: case report.

Clear cell adenocarcinoma of the cervix is a rare tumor of the lower genital tract. It has been described in young women with a history of intra uterine exposure to diethylstilbestrol. This tumor is characterized by a greater tendency for late recurrences. In this article, we report the case of one exposed-patient who developed recurrence as liver metastases, 24 years after the initial treatment. This case demonstrates the need and the importance for continued follow-up in individuals prenatally exposed to diethylstilbestrol.

Treatment of cancer cells with methioninase produces DNA hypomethylation and increases DNA synthesis.

Methionine depletion in the human cell line CCRF-CEM through the action of recombinant methioninase (rMETase), a methionine-cleaving enzyme, was previously demonstrated to produce a strong cytotoxic synergistic effect with fluorouracil (FUra) throughout a broad range of concentrations of FUra and rMETase, including subcytotoxic levels of rMETase. Potentiation was associated with a decrease in free thymidylate synthase from preexisting levels. To further investigate the action of rMETase on CCRF-CEM cells, in the present study we explored the effects of rMETase as a single agent on DNA methylation levels and DNA synthesis, which may be changed as a result of deprivation of methionine. Cells treated with rMETase under subcytotoxic conditions contained significantly lower levels of genomic methylated DNA than did control cells, as demonstrated by incorporation of the methyl radical of [methyl-(3)H]S-adenosylmethionine in DNA and by use of methylation-sensitive arbitrarily primed PCR. DNA hypomethylation produced by rMETase was of similar magnitude as that produced with the DNA methyltransferase inhibitor 5-azacytidine. Cells exposed to rMETase synthesized significantly more DNA than did untreated cells. Incorporation of [6-3H]thymidine and [6-3H]2'-deoxyuridine in these cells was augmented over that in control by mean factors of 1.78 and 2.36, respectively. Increased 3H nucleoside incorporation resulted in greater numbers of nuclear grains as demonstrated by autoradiography. The increase in DNA synthesis induced by rMETase is likely to result from enhancement of DNA repair because it was not accompanied by differences in cell cycle phase distribution or in total DNA content as determined by flow cytometry. We hypothesize that potentiation of FUra cytotoxicity by rMETase may result from increased inhibition of thymidylate synthase, together with DNA hypomethylation and enhanced DNA repair that could be involved in cell responses to drug-induced damage.