Tolerable sorafenib therapy for a renal cell carcinoma patient with hemodialysis: a case study

Sorafenib (Nexavar^®) has been approved for the treatment of advanced renal cell carcinoma (RCC) and hepatocellular carcinoma. There is little information on the dosage adjustment of sorafenib for patients with end-stage renal failure. Herein, we have examined the effect of hemodialysis on the pharmacokinetics of sorafenib and its major active metabolite, M-2, and assessed sorafenib-related toxicity throughout the therapy. The patient was a 54-year-old man who was diagnosed with advanced RCC. Pharmacokinetic analysis was carried out on days 9 and 183. The patient had stable disease on day 77 and showed progression on day 181. He has received about 6 months of continuous treatment with sorafenib 800 mg/day without any clinically relevant toxicity. The pharmacokinetic parameters of sorafenib such as C _max and AUC_0–12 on day 183 were in the range of the reference values reported in patients with normal renal function. Our results suggest that sorafenib administered at a dose of 400 mg twice per day was well tolerated, at least for 6 months, for a patient undergoing hemodialysis.     

Autophagy is activated in colorectal cancer cells and contributes to the tolerance to nutrient deprivation

Several types of cancer cells, including colorectal cancer-derived cell lines, show austerity, the resistance to nutrient starvation, but exactly how cancer cells obtain energy sources under conditions in which their external nutrient supply is extremely limited remains to be clarified. Because autophagy is a catabolic process by which cells supply amino acids from self-digested organelles, cancer cells are likely to use autophagy to obtain amino acids as alternative energy sources. Amino acid deprivation-induced autophagy was assessed in DLD-1 and other colorectal cancer-derived cell lines. The autophagosome-incorporated LC3-II protein level increased after treatment with a combination of autolysosome inhibitors, which interferes with the consumption of autophagosomes. Autophagosome formation was also morphologically confirmed using ectopically expressed green fluorescent protein-LC3 fusion proteins in DLD-1 and SW480 cells. These data suggest that autophagosomes were actively produced and promptly consumed in colorectal cancer cells under nutrient starvation. Autolysosome inhibitors and 3-methyl adenine, which suppresses autophagosome formation, remarkably enhanced apoptosis under amino acid-deprived and glucose-deprived condition. Similar results were obtained in the cells with decreased ATG7 level by the RNA interference. These data suggest that autophagy is pivotal for the survival of colorectal cancer cells that have acquired austerity. Furthermore, autophagosome formation was seen only in the tumor cells but not in the adjacent noncancerous epithelial cells of colorectal cancer specimens. Taken together, autophagy is activated in colorectal cancers in vitro and in vivo, and autophagy may contribute to the survival of the cancer cells in their microenvironment.     

Improvement of the tumor-suppressive effect of boron neutron capture therapy for amelanotic melanoma by intratumoral injection of the tyrosinase gene

Boron neutron capture therapy (BNCT) is successful when there is a sufficient (10)B concentration in tumor cells. In melanoma, (10)B-para-boronophenylalanine (BPA) accumulation is proportional to melanin-producing activity. This study was done to confirm enhancement of the tumor-suppressive effect of BNCT on amelanotic melanoma by intratumoral injection of the tyrosinase gene. D178 or FF amelanotic melanomas were implanted s.c. in Syrian hamsters. One group of D178- or FF-bearing hamsters (TD178 or TFF group) received intratumoral injections of pcDNA-Tyrs constructed as a tyrosinase expression plasmid. The other hamsters (pD178 and pFF groups) were injected with pUC119, and control hamsters (D178 and FF groups) only with transfection reagents. All the groups underwent immunofluorescence analysis of tyrosinase expression and BPA biodistribution studies. BNCT experiments were done at the Kyoto University Research Reactor. Tyrosinase expression increased in the tumors of the TD178 and TFF groups but remained the same in the pD178 and pFF groups. Tumor boron concentrations in the TD178 and TFF groups increased significantly (TD178: 49.7 +/- 12.6 versus D178: 27.2 +/- 4.9 microg/g, P < 0.0001; TFF: 30.7 +/- 6.6 versus FF: 13.0 +/- 4.7 microg/g, P < 0.0001). The BNCT tumor-suppressive effect was marked in the TD178 and TFF groups. In vivo transfection with the tyrosinase gene increased BPA accumulation in the tumors, the BNCT tumor-suppressive effect on amelanotic melanoma being significantly enhanced. These findings suggest a potential new clinical strategy for the treatment of amelanotic melanoma with BNCT.     

Mutations of the epidermal growth factor receptor gene in gastrointestinal tract tumor cell lines

The epidermal growth factor receptor (EGFR) is commonly overexpressed in many human tumors including gastrointestinal tract tumors. Gefitinib is a selective inhibitor of EGFR tyrosine kinase, and blocks several signal transduction pathways including those involved in tumor cell proliferation, angiogenesis and metastasis. Recent mutational and biological studies have suggested that mutations in the tyrosine kinase domain of the EGFR gene are well correlated with the response to gefitinib, and that these mutations are frequently observed in non-small cell lung cancers affecting women, East Asians and non-smokers. This led us to speculate that EGFR gene mutations may occur frequently in gastrointestinal tract carcinomas (GITCs) because overexpression is observed in these tumor types. To investigate EGFR mutations in GICTs, we studied 11 esophageal, 6 gastric, and 12 colorectal cancer cell lines. We found a missense mutation in a gastric cancer cell line, and 10 single nucleotide polymorphisms. The occurrence of rare mutations in the tyrosine kinase domain of the EGFR gene suggests that gefitinib is unlikely to be reliable as single-drug therapy for GITCs.     

Association between carotenoids and outcome of cervical intraepithelial neoplasia: a prospective cohort study

Background

It has been suggested that micronutrients such as alpha-tocopherol, retinol, lutein, cryptoxanthin, lycopene, and alpha- and beta-carotene may help in the prevention of cervical cancer. Our aim was to investigate whether serum concentrations and/or dietary intake of micronutrients influence the regression or progression of low-grade cervical abnormalities.

Methods

In a prospective cohort study of 391 patients with cervical intraepithelial neoplasia (CIN) grade 1–2 lesions, we measured serum micronutrient concentrations in addition to a self-administered questionnaire about dietary intake. We evaluated the hazard ratio (HR) adjusted for CIN grade, human papillomavirus genotype, total energy intake and smoking status.

Results

In non-smoking regression subjects, regression was significantly associated with serum levels of zeaxanthin/lutein (HR 1.25, 0.78–2.01, p = 0.024). This benefit was abolished in current smokers. Regression was inhibited by high serum levels of alpha-tocopherol in smokers (p = 0.042). In progression subjects, a significant protective effect against progression to CIN3 was observed in individuals with a medium level of serum beta-carotene [HR 0.28, 95 % confidence interval (CI) 0.11–0.71, p = 0.007), although any protective effect from a higher level of serum beta-carotene was weaker or abolished (HR 0.52, 95 % CI 0.24–1.13, p = 0.098). Increasing beta-carotene intake did not show a protective effect (HR 2.30, 95 % CI 0.97–5.42, p = 0.058).

Conclusions

Measurements of serum levels of carotenoids suggest that regression is modulated by smoking status. Maintaining a medium serum level of beta-carotene has a protective effect for progression; however, carotene intake is not correlated with serum levels of carotenoids.

     

Identification of intravascular tumor microenvironment features predicting the recurrence of pathological stage I lung adenocarcinoma

Histological vascular invasion (VI) by tumors is reportedly a risk factor influencing recurrence or survival after surgical treatment; however, few studies have evaluated which VI features affect recurrence or survival. The objective of this study was to evaluate how VI features affect recurrence in lung adenocarcinoma patients. We selected 106 patients with pathological stage I lung adenocarcinoma who showed VI and examined the properties of intravascular tumors associated with recurrence. First we investigated the relationship between the frequency of VI in a histological cross‐section and the incidence of recurrence; however, a significant impact was not observed. Microscopic examination revealed the intravascular tumors were composed of not only cancer cells but also non‐cancerous cells. To examine whether the characteristics of intravascular cancer cells and/or non‐cancerous cells have prognostic value, we examined the expression levels of epithelial–mesenchymal transition‐related markers in cancer cells and the numbers of infiltrating non‐cancerous cells, including macrophages, endothelial cells, and fibroblasts. High levels of E‐cadherin expression in the intravascular cancer cells were significant predictors of recurrence (P = 0.004), whereas the expressions of CD44, CD44 variant 6, and vimentin were not. Large numbers of intravascular CD204(+) macrophages (P = 0.016), CD34(+) microvessels (P = 0.007), and α‐smooth muscle actin (+) fibroblasts (P = 0.033) were also significant predictors of recurrence. Our results indicated VI with abundant stromal cell infiltrates might be a predictor of recurrence and suggested the tumor microenvironment created by cancer cells and stromal cells within the blood vessel may play an important role during the metastatic process.     

Ziram induces apoptosis and necrosis in human immune cells

Ziram as a dithiocarbamate fungicide is widely used throughout the world in agriculture and as an accelerating agent is used in latex production. In order to investigate ziram-induced apoptosis/necrosis and its underlying mechanism in human immune cells, a human monocyte-like cell line (U937) was treated with ziram at 0.0312–2 μM for 2–24 h at 37°C in a 5% CO₂ incubator. Apoptosis/necrosis induced by ziram was determined by analysis of FITC-Annexin-V/PI staining and the intracellular level of active caspase-3 by flow cytometry and DNA fragmentation analysis. We found that ziram induced apoptosis/necrosis in U937 in a time- and dose-dependent manner, as shown by FITC-Annexin-V/PI staining. DNA fragmentation was detected when cells were treated with 0.5, 1, or 2 μM ziram for 24 h. Ziram also induced an increase in intracellular active caspase-3 in U937 cells in a dose-dependent manner, and a caspase-3 inhibitor, Z-DEVD-FMK, significantly inhibited the ziram-induced apoptosis. Moreover, it was found that ziram induced mitochondrial cytochrome c release in U937 cells. These findings indicate that ziram can induce apoptosis/necrosis in U937 cells, and this effect is partially mediated by activation of intracellular caspase-3 and mitochondrial cytochrome c release.     

Inactivated Sendai virus particle upregulates cancer cell expression of intercellular adhesion molecule‐1 and enhances natural killer cell sensitivity on cancer cells

We have already reported that the inactivated Sendai virus (hemagglutinating virus of Japan; HVJ) envelope (HVJ‐E) has multiple anticancer effects, including induction of cancer‐selective cell death and activation of anticancer immunity. The HVJ‐E stimulates dendritic cells to produce cytokines and chemokines such as β‐interferon, interleukin‐6, chemokine (C‐C motif) ligand 5, and chemokine (C‐X‐C motif) ligand 10, which activate both CD8⁺ T cells and natural killer (NK) cells and recruit them to the tumor microenvironment. However, the effect of HVJ‐E on modulating the sensitivity of cancer cells to immune cell attack has yet to be investigated. In this study, we found that HVJ‐E induced the production of intercellular adhesion molecule‐1 (ICAM‐1, CD54), a ligand of lymphocyte function‐associated antigen 1, in several cancer cell lines through the activation of nuclear factor‐κB downstream of retinoic acid‐inducible gene I and the mitochondrial antiviral signaling pathway. The upregulation of ICAM‐1 on the surface of cancer cells increased the sensitivity of cancer cells to NK cells. Knocking out expression of ICAM‐1 in MDA‐MB‐231 cells using the CRISPR/Cas9 method significantly reduced the killing effect of NK cells on ICAM‐1‐depleted MDA‐MB‐231 cells. In addition, HVJ‐E suppressed tumor growth in MDA‐MB‐231 tumor‐bearing SCID mice, and the HVJ‐E antitumor effect was impaired when NK cells were depleted by treatment with the anti‐asialo GM1 antibody. Our findings suggest that HVJ‐E enhances NK cell sensitivity against cancer cells by increasing ICAM‐1 expression on the cancer cell surface.