The effect of 5-fluorouracil and alpha interferon and 5-fluorouracil and leucovorin on cellular anti-tumour immune responses in patients with advanced colorectal cancer

Identification of an Autophagy-Related Gene Signature for the Prediction of Prognosis in Early-Stage Colorectal Cancer

Purpose: A certain number of early-stage colorectal cancer (CRC) patients suffer tumor recurrence after initial curative resection. In this context, an effective prognostic biomarker model is constantly in need. Autophagy exhibits a dual role in tumorigenesis. Our study aims to develop an autophagy-related gene (ATG) signature-based on high-throughput data analysis for disease-free survival (DFS) prognosis of patients with stage I/II CRC.

Methods: Gene expression profiles and clinical information of CRC patients extracted from four public datasets were distributed to discovery and training cohort (GSE39582), validation cohort (TCGA CRC, n = 624), and meta-validation cohort (GSE37892 and GSE14333, n = 420). Autophagy genes significantly associated with prognosis were identified.

Results: Among 655 autophagy-related genes, a 10-gene ATG signature, which was significantly associated with DFS in the training cohort (HR, 2.76[1.56–4.82]; p = 2.06 × 10–4), was constructed. The ATG signature, stratifying patients into high and low autophagy risk groups, was validated in the validation (HR, 2.29[1.15–4.55]; p = 1.5 × 10–2) and meta-validation cohorts (HR, 2.5[1.03–6.06]; p = 3.63 × 10–2) and proved to be prognostic in a multivariate analysis. Functional analysis revealed enrichment of several immune/inflammatory pathways in the high autophagy risk group, where increased infiltration of T regulatory cells (Tregs) and decreased infiltration of M1 macrophages were observed.

Conclusion: Our study established a prognostic ATG signature that effectively predicted DFS for early-stage CRC patients. Meanwhile, the study also revealed the possible relationship among autophagy process, immune/inflammatory response, and tumorigenesis.

Autophagic Mechanism in Anti-Cancer Immunity: Its Pros and Cons for Cancer Therapy

Autophagy, a self-eating machinery, has been reported as an adaptive response to maintain metabolic homeostasis when cancer cells encounter stress. It has been appreciated that autophagy acts as a double-edge sword to decide the fate of cancer cells upon stress factors, molecular subtypes, and microenvironmental conditions. Currently, the majority of evidence support that autophagy in cancer cells is a vital mechanism bringing on resistance to current and prospective treatments, yet whether autophagy affects the anticancer immune response remains unclear and controversial. Accumulated studies have demonstrated that triggering autophagy is able to facilitate anticancer immunity due to an increase in immunogenicity, whereas other studies suggested that autophagy is likely to disarm anticancer immunity mediated by cytotoxic T cells and nature killer (NK) cells. Hence, this contradiction needs to be elucidated. In this review, we discuss the role of autophagy in cancer cells per se and in cancer microenvironment as well as its dual regulatory roles in immune surveillance through modulating presentation of tumor antigens, development of immune cells, and expression of immune checkpoints. We further focus on emerging roles of autophagy induced by current treatments and its impact on anticancer immune response, and illustrate the pros and cons of utilizing autophagy in cancer immunotherapy based on preclinical references.

Relationship between immunological parameters and the severity of neutropenia and effect of enteral nutrition on immune status during neoadjuvant chemotherapy on patients with advanced esophageal cancer

OBJECTIVES

Chemotherapy may cause various toxicities as well as impair immunological function. However, little is known about the relationship between toxicities and immunological parameters or the effect of enteral nutrition (EN) on immunological status during chemotherapy.

METHODS

91 patients who received neoadjuvant chemotherapy (NACT) for esophageal cancer were randomly assigned to receive either EN or parenteral nutrition (PN). Immunological parameters, including total lymphocyte count (TLC), type 1 and type 2 CD4-positive T cells (Th1/Th2) balance, human leukocyte antigen (HLA)-DR expression on monocytes, natural killer cell activity, and phytohemagglutinin-stimulated lymphocyte proliferation were measured at baseline and day 14 of the first chemotherapy cycle.

RESULTS

In the PN group, patients with grade 3-4 neutropenia showed significantly lower TLC, HLA-DR expression, and Th1/Th2 balance at day 14 compared to those with grade 0-2 neutropenia. Among pretherapeutic factors, Th1/Th2 balance was the only factor significantly associated with the severity of neutropenia. Concerning the comparison of immunological parameters between the EN and PN groups, HLA-DR expression at day 14 was significantly higher in the EN group.

CONCLUSIONS

Baseline Th1/Th2 balance predicted the severity of neutropenia, and EN significantly reduced the decline of monocyte HLA-DR expression in patients with esophageal cancer receiving NACT.

Mismatch repair and response to DNA-damaging antitumour therapies

Most antitumour therapies damage tumour cell DNA either directly or indirectly. DNA damage responses, and particularly DNA repair, influence the outcome of therapy. Because DNA repair normally excises lethal DNA lesions, it is intuitive that efficient repair will contribute to intrinsic drug resistance. Indeed, in certain circumstances reduced levels of DNA nucleotide excision repair are associated with a good therapeutic outlook (Curr Biol 9 (1999) 273). A paradoxical relationship between DNA mismatch repair (MMR) and drug sensitivity has been revealed by model studies in cell lines. This suggests that connections between MMR and tumour therapy might be more complex. Here, we briefly review how MMR deficiency can affect drug resistance and the extent to which loss of MMR is a prognostic factor in certain cancer therapies. We also consider how the inverse relationship between MMR activity and drug resistance might influence the development of treatment-related malignancies which are increasingly linked to MMR defects.

Toxicity and effects of adjuvant therapy in colon cancer: results of the German prospective, controlled randomized multicenter trial FOGT-1

In this adjuvant three-arm multicenter trial, we studied whether modulating the standard 5-fluorouracil (5-FU) treatment with either folinic acid (FA) or interferon-alpha-2a (IFN-alpha) was superior to the recommended standard of adjuvant treatment in R0 resected colon cancer, 5-FU plus levamisole (LEV) for 12 months, in terms of toxicity and outcome. From July 1992 to October 1999, a total of 813 patients with resected colon cancer in stage II (T4N0M0; n = 63) or stage III (TxN1-3M0; n = 750) were randomized into three treatment groups and stratified according to N stage and participating centers (64 hospitals). The patients received a postoperative loading dose of 5-FU (450 mg/m2 on days 1 to 5 [arms A and C]) or 5-FU (450 mg/m2) plus FA (Rescuvolin, Medac, Hamburg, Germany, 200 mg/m2 on days 1 to 5 [arm B]). After completion of the first chemotherapy cycle, LEV was administered orally at a dosage of 150 mg per day on days 1 to 3, once every 2 weeks. After a 4-week chemotherapy-free interval, the treatment was continued weekly for 52 weeks. Treatment in one arm A ("standard") (n = 279) consisted of 5-FU intravenously (450 mg/m2 on day 1, once a week) plus LEV. 5-FU plus LEV was modulated in arm B (n = 283) with FA (200 mg/m2 on day 1, once a week) and in arm C (n = 251) with IFN-alpha at 6 million units three times a week repeated weekly. Treatment dosages were adjusted if toxic events above WHO grade 2 occurred. Patients were closely followed to determine recurrence and survival; the latter was calculated according to Kaplan-Meier analysis. Toxic events above WHO grade 2, mainly leukopenia, diarrhea, and nausea, occurred in 113 (14%) of 649 patients who had completed treatment in arms A (8.4%), B (13.5%), and C (31.7%). Discontinuance rates were as follows: 28% for all patients, 29% in arm A, 21% in arm B, and 34% in arm C. Overall relapse rates were 27% for all patients, 30% in arm A, 24% in arm B, and 28% in arm C. Relapses were local (8%), distant (78%), or combined (12%). Four-year overall survival rates in arms A, B, and C were 66.1%, 77.5%, and 66.2%, respectively. The 4-year survival rate in arm B was significantly higher compared to arm A (P <0.02, log-rank test) with arm A being equal to arm C. Adjuvant therapy with 5-FU plus FA plus LEV for 12 months is superior to the recommended standard (5-FU + LEV for 12 months). IFN-alpha modulation of 5-FU (plus LEV) adds to the toxicity with no therapeutic benefit.

Synergistic inhibitory effects of interferon-alpha and 5-fluorouracil in meningioma cells in vitro

We have investigated the effects of interferon-alpha (IFN-alpha) and 5-fluorouracil (5-FU) on meningioma cells in two different culture systems, evaluated by the uptake of radiolabelled methionine. With both IFN-alpha and 5-FU an inhibitory effect on the uptake of radiolabelled methionine by the meningioma cells was demonstrated, and we found a synergistic inhibitory effect with a combination of IFN-alpha and 5-FU. To obtain a maximal inhibition of cell metabolism without causing cell toxicity, we were able to decrease the dose of 5-FU by simultaneously adding IFN-alpha. Our results suggest that a combined treatment of IFN-alpha and 5-FU may be a successful alternative for patients with inoperable meningiomas. A novel in vitro positron emission tomography technique was used for the study of metabolic changes in tumour cells caused by drug treatment, which is complementary to conventional cell culture techniques.