[Use of granulocyte-colony stimulating factor(G-CSF)in patients with cancer at high risk of febrile neutropenia on the basis of high age and complications, recommendations for patients receiving radiotherapy, and adverse events because of G-CSF].

Neutropenic complications are the primary dose-limiting toxic effects observed in patients treated with systemic cancer chemotherapy. Broad-spectrum antibiotic therapy should be promptly administered to patients with febrile neutropenia(FN). The risk assessment of FN includes the disease characteristics, chemotherapy regimen, individual patient risk factors, and treatment intent. After considering such risk factors of FN, clinicians should appropriately consider the use of granulocytecolony stimulating factor(G-CSF)as a prophylactic or therapeutic measure. Some types of lymphoma can be cured with chemotherapy. The incidence of FN in patients receiving the standard rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone(R-CHOP)regimen is approximately 20%. Primary prophylactic use of G-CSF is recommended for patients agedB 65 years having diffuse aggressive lymphoma and treated with curative chemotherapy in an effort to improve their quality of life(QOL). Primary prophylaxis is recommended for the prevention of FN in patients at high risk, on the basis of factors other than age. G-CSF should be avoided in patients receiving concomitant chemotherapy and radiation therapy, particularly in those with cancer involving the mediastinum. The adverse events of G-CSF are generally graded mild to moderate; however, rare life-threatening adverse effects have been published in the literature. A clinical practice guideline for the use of G-CSF was published by the Japan Society of Clinical Oncology in 2013. On the basis of this guideline, the above issues have been discussed in this paper.

Methylation of the KEAP1 gene promoter region in human colorectal cancer.

BACKGROUND: The Keap1-Nrf2 pathway has been reported to be impaired in several cancers. However, the status of Keap1-Nrf2 system in human colorectal cancer (CRC) has not been elucidated. METHODS: We used colorectal cancer (CRC) cell lines and surgical specimens to investigate the methylation status of the KEAP1 promoter region as well as expression of Nrf2 and its downstream antioxidative stress genes, NQO-1 and AKR1C1. RESULTS: DNA sequencing analysis indicated that all mutations detected were synonymous, with no amino acid substitutions. We showed by bisulfite genomic sequencing and methylation-specific PCR that eight of 10 CRC cell lines had hypermethylated CpG islands in the KEAP1 promoter region. HT29 cells with a hypermethylated KEAP1 promoter resulted in decreased mRNA and protein expression but unmethylated Colo320DM cells showed higher expression levels. In addition, treatment with the DNA methyltransferase inhibitor 5-Aza-dC combined with the histone deacetylase inhibitor trichostatin A (TSA) increased KEAP1 mRNA expression. These result suggested that methylation of the KEAP1 promoter regulates its mRNA level. Time course analysis with the Nrf2-antioxidant response element (ARE) pathway activator t-BHQ treatment showed a rapid response within 24 h. HT29 cells had higher basal expression levels of NQO-1 and AKR1C1 mRNA than Colo320DM cells. Aberrant promoter methylation of KEAP1 was detected in 53% of tumor tissues and 25% of normal mucosae from 40 surgical CRC specimens, indicating that cancerous tissue showed increased methylation of the KEAP1 promoter region, conferring a protective effect against cytotoxic anticancer drugs. CONCLUSION: Hypermethylation of the KEAP1 promoter region suppressed its mRNA expression and increased nuclear Nrf2 and downstream ARE gene expression in CRC cells and tissues.

[A case of gastric adenosquamous carcinoma successfully treated with second-line chemotherapy (CPT-11 and CDDP)].

Gastric adenosquamous carcinoma is known as an infrequent histological cancer with a poor prognosis. A 69-year-old man was revealed to have gastric squamous carcinoma on the gastric body remote from esophagus (cT4 cN3, cStage IV). A curative operation was impossible so he was treated with systemic chemotherapy using S-1+docetaxel. After 1 course, we changed to second-line chemotherapy combining CPT-11+CDDP because of heterochronic multiple hepatic metastases. PET-CT and CT findings after 5 courses of second-line therapy showed reduced primary tumor and metastatic lesions. The curative operation was performed based on the effective response with downstaging. The final histological diagnosis showed gastric adenosquamous carcinoma. The adjuvant chemotherapy of CPT-11 was continued without relapse for almost 2 years.

[A case of unresectable advanced gastric cancer with Trousseau syndrome].

Cancer-related coagulopathy is known as Trousseau syndrome with a poor prognosis. A 55-year-old woman was revealed to have gastric cancer (cT3 cN3, cStage IV) with deep vein thrombosis and pulmonary embolism. A curative operation was impossible so she was treated with systemic chemotherapy using S-1 combined with an anticoagulant agent (warfarin). Some studies indicated that the interaction between S-1 and warfarin might cause strong effects of their mutual interaction. Although the dose of warfarin had to be decreased, this patient was able to take both drugs safely without this severe adverse effect until a shift to palliative therapy.

Influence of cancer-related gene polymorphisms on clinicopathological features in colorectal cancer.

BACKGROUND AND AIM: Single nucleotide polymorphisms (SNP) are shown to be related with cancer incidence. It has been reported that CCND1, p21(cip1)DCC, MTHFR, and EXO1 are related with the risk of malignant neoplasm, but few studies have mentioned the prognosis of the patients. We investigated the SNP of patients and related this to clinicopathological features, including survival rate. METHOD: DNA from the tissues of primary colorectal cancer was obtained from surgical resections of 114 patients (68 males and 46 females, 29-83 years). The CCND1 polymorphism was analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and those of other genes were investigated by the TaqMan method. The polymorphisms obtained were statistically analyzed for the relationship with clinicopathological features. RESULTS: The CG + GG allele was more invasive than the CC allele in histological tumor depth in the DCC codon 201 (P = 0.0086). The 677TT allele in MTHFR had a larger tumor size than the 677CC allele (P = 0.028). In EXO1 P757L polymorphism, patients with the TT allele had a statistically reduced survival rate compared with the other alleles. In CCND1 polymorphisms, we found no statistical significance in clinicopathological features. CONCLUSIONS: From these preliminary data, these polymorphisms would be candidates predicting the clinicopathological features of colorectal cancer, but further more systematic gene analyses are warranted.

Interconversion of intra- and extra-chromosomal sites of gene amplification by modulation of gene expression and DNA methylation.

We previously showed that plasmids containing a mammalian replication initiation region and a matrix attachment region were efficiently amplified to few thousand copies per cell, and that they formed extrachromosomal double minutes (DMs) or chromosomal homogeneously staining regions (HSRs). In these structures, the plasmid sequence was arranged as a tandem repeats, and we suggested a mechanism of plasmid amplification. Since amplification was very efficient, easy, and convenient, it might be adapted to a novel method for protein production. In the current study, we found that gene expression from the tandem plasmid repeat was suppressed. We identified several strategies to overcome this suppression, including: (1) use of higher concentrations of antibiotic during cell selection; (2) treatment of cells with agents that influence DNA methylation (5-azacytidine) or histone acetylation (butyrate); (3) co-amplification of an insulator sequence; and (4) co-amplification of sequences that encode a transcriptional activator. Expression from the plasmid repeat was always higher at DMs compared to HSRs. We found that continuous activation of a plasmid-encoded inducible promoter prevented the generation of long HSRs, and favored amplification at DMs. Consistent with this finding, there was a synergistic effect of transcriptional activation and inhibition of DNA methylation on the fragmentation of long HSRs and the generation of DMs and short HSRs. Our results indicate that both transcriptional activation and DNA methylation regulate the interconversion between extra- and intra-chromosomal gene amplification. These results have important implications for both protein production technology, and the generation of chromosomal abnormalities found in human cancer cells.