Challenging case of deficient mismatch repair right-sided locally advanced adenocarcinoma of the ascending colon with duodenal involvement: A case report including step-by-step video of operation.

INTRODUCTION AND IMPORTANCE: Irresectable colon cancer presents a complex clinical challenge. Neoadjuvant immunotherapy has shown potential in improving resectability. Additionally, advancements in surgical techniques, including complete mesocolic excision (CME) with central vascular ligation (CVL), have contributed to better outcomes for right-sided colon cancer. This case report aims to demonstrate the successful laparoscopic resection of initial appearing irresectable colon cancer with suspected duodenal involvement. CASE PRESENTATION: A 70-year-old female presented with an irresectable mismatch repair deficient (dMMR) adenocarcinoma of the ascending colon with suspected duodenal ingrowth. Neoadjuvant treatment with pembrolizumab and ataluren resulted in a significant response, allowing for surgical resection. A laparoscopic right hemicolectomy with CME, including CVL, intracorporeal anastomosis and extraction through a Pfannenstiel incision, was performed. Additionally, the serosal layer of the duodenum was shaved after observing the absence of intraluminal invasion. Postoperatively, transient gastroparesis occurred, but overall outcomes were favourable. CLINICAL DISCUSSION: This case emphasizes the potential of immunotherapy in improving resectability for irresectable dMMR colon cancer with suspected involvement of surrounding organs. The combination of neoadjuvant therapy and advanced surgical techniques, such as CME with CVL, shows promise in achieving favourable clinical outcomes. However, further studies are needed to validate the effectiveness and safety of this combined approach in a larger cohort of patients. CONCLUSION: The successful laparoscopic resection of initially irresectable dMMR colon cancer with duodenal involvement, following neoadjuvant immunotherapy, demonstrated promising outcomes. This case advocates for further exploration of neoadjuvant treatments' efficacy, coupled with advanced surgical techniques, in managing locally advanced right-sided colon cancer.

Antiplatelet drugs may increase the risk for checkpoint inhibitor-related pneumonitis in advanced cancer patients.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are indicated for various cancers and are the mainstay of cancer immunotherapy. They are often associated with ICI-related pneumonitis (CIP), however, hindering a favorable clinical course. Recently, non-oncology concomitant drugs have been reported to affect the efficacy and toxicity of ICIs; however, the association between these drugs and the risk for CIP is uncertain. The aim of this study was to assess the impact of baseline concomitant drugs on CIP incidence in ICI-treated advanced cancer patients. PATIENTS AND METHODS: This was a single-center retrospective study that included a cohort of 511 patients with advanced cancer (melanoma and non-small-cell lung, head and neck, genitourinary, and other types of cancer) treated with ICIs. Univariable analysis was conducted to identify baseline co-medications associated with CIP incidence. A propensity score matching analysis was used to adjust for potential CIP risk factors, and multivariable analysis was carried out to assess the impact of the identified co-medications on CIP risk. RESULTS: Forty-seven (9.2%) patients developed CIP. In these patients, the organizing pneumonia pattern was the dominant radiological phenotype, and 42.6% had grade ≥3 CIP, including one patient with grade 5. Of the investigated baseline co-medications, the proportion of antiplatelet drugs (n = 50, 9.8%) was higher in patients with CIP (23.4% versus 8.4%). After propensity score matching, the CIP incidence was higher in patients with baseline antiplatelet drugs (22% versus 6%). Finally, baseline antiplatelet drug use was demonstrated to increase the risk for CIP incidence regardless of cancer type (hazard ratio, 3.46; 95% confidence interval 1.21-9.86). CONCLUSIONS: An association between concomitant antiplatelet drug use at baseline and an increased risk for CIP was seen in our database. This implies the importance of assessing concomitant medications for CIP risk management.

Framing the potential of public frameshift peptides as immunotherapy targets in colon cancer.

Approximately 15% of Colon Cancers are Microsatellite Instable (MSI). Frameshift Peptides (FPs) formed in MSI Colon Cancer are potential targets for immunotherapeutic strategies. Here we comprehensively characterize the mutational landscape of 71 MSI Colon Cancer patients from the cancer genome atlas (TCGA). We confirm that the mutations in MSI Colon Cancers are frequently frameshift deletions (23% in MSI; 1% in microsatellite stable), We find that these mutations cluster at specific locations in the genome which are mutated in up to 41% of the patients. We filter these for an adequate variant allele frequency, a sufficient mean mRNA level and the formation of a Super Neo Open Reading Frame (SNORF). Finally, we check the influence of Nonsense Mediated Decay (MMD) by comparing RNA and DNA sequencing results. Thereby we identify a set of 20 NMD-escaping Public FPs (PFPs) that cover over 90% of MSI Colon, 62.2% of MSI Endometrial and 58.8% of MSI Stomach cancer patients and 3 out of 4 Lynch patients in the TCGA-COAD. This underlines the potential for PFP directed immunotherapy, both in a therapeutic and a prophylactic setting in multiple types of MSI cancers.

Ischaemic colitis during interferon treatment for chronic hepatitis C: report of two cases and literature review.

Ischaemic colitis is known to be a severe emergency complication of interferon (IFN) therapy. However, as ischaemic colitis is an infrequent complication of IFN therapy, limited information is available regarding the safety of resuming IFN therapy after resolution of ischaemic colitis and subsequent recurrence. Here, we report two cases of ischaemic colitis during IFN therapy for chronic hepatitis C. Ischaemic colitis was fully healed within 1 week after its onset and IFN withdrawal, and IFN therapy was resumed following patients' wishes to do so. Ischaemic colitis did not recur after the resumption of IFN therapy, and sustained virological response was achieved in both patients. In this report, we also summarize the findings of 11 cases of IFN-associated ischaemic colitis (nine previously published cases plus our two cases) and review the clinical characteristics of ischaemic colitis during IFN therapy in patients with chronic hepatitis C.

Expression of cell adhesion molecules and doublecortin in canine anaplastic meningiomas.

Tumor cell invasion into the surrounding nervous tissue is one of the histologic hallmarks of anaplastic meningiomas. To identify other possible markers for aggression in canine meningiomas, the relationship between histologic features and the expression of molecules involved in cell adhesion, cell proliferation, and invasion was examined. Immunohistochemistry for epithelial cadherin (E-cadherin), neural cadherin (N-cadherin), ß-catenin, doublecortin (DCX), and Ki-67 was performed for 55 cases of canine meningioma. DCX was preferentially expressed in tumor cells invading the brain parenchyma (12 of 14 cases), suggesting its involvement in the invasion process. Regardless of the histologic type, E-cadherin and N-cadherin expression was observed in 31 of 55 and 44 of 55 cases, respectively. There was a significant positive correlation between DCX and N-cadherin expression and a significant negative correlation between E-cadherin and N-cadherin expression, suggesting that decreased E-cadherin and increased N-cadherin expression induce DCX expression. Typical membranous ß-catenin expression was observed in 10 of 55 cases, whereas nuclear translocation was observed in 33 cases. Nuclear ß-catenin expression was frequently found in anaplastic meningiomas (12 of 14 cases). The Ki-67 labeling indices were significantly higher in anaplastic meningiomas than in other types. These findings indicate that the expression of N-cadherin and DCX and the nuclear translocation of ß-catenin are closely associated with the presence of invasion and anaplasia in canine meningiomas. Notably, granular cell meningiomas were negative for almost all the molecules examined, suggesting that they have a different tumor biology than other meningiomas.

Immunohistochemical characterization of canine neuroepithelial tumors.

The expression of cell differentiation and proliferation markers of canine neuroepithelial tumors was examined immunohistochemically to identify the histogenesis of these tumors. Astrocytomas (n = 4) consisted of cells positive for glial fibrillary acidic protein (GFAP) and nestin and a few cells positive for doublecortin (DCX). Immunoreactive cells for receptor tyrosine kinases (epidermal growth factor receptor and c-erbB2) and their downstream molecules (phospho-extracellular signal-regulated kinase 1/2 and phospho-Akt) were often detected in astrocytomas, especially in medium- and high-grade tumors. Gliomatosis cerebri (n = 3) consisted of cells positive for ionized calcium-binding adaptor molecule 1 and GFAP, including a minor population of cells positive for nestin, DCX, and beta III tubulin, suggesting their glial differentiation. In choroid plexus tumors (n = 4), most tumor cells were positive for cytokeratins AE1/AE3 and 18, and few were positive for GFAP. The majority of cells of oligodendrogliomas (n = 5) were DCX positive, but the tumors also contained minor populations of cells positive for GFAP, nestin, or beta III tubulin. Primitive neuroectodermal tumors (PNETs; n = 2) consisted of heterogeneous cell populations, and the tumor cells were positive for nestin, beta III tubulin, and DCX, suggesting glial and neuronal differentiation. The major population of neuroblastoma cells (n = 3) were positive for beta III tubulin and DCX, suggesting single neuronal differentiation. As for antiapoptotic cell death molecules, most tumor cells in the choroid plexus tumors, PNETs, and neuroblastomas were intensely positive for Bcl-2 and Bcl-xL, whereas those in gliomatosis cerebri were almost negative. In astrocytomas, Bcl-xL-positive cells predominated over Bcl-2-positive cells, but the opposite was observed in oligodendrogliomas. The immunohistochemical results were analyzed by hierarchical clustering, and the constructed dendrogram clearly indicated a novel position of oligodendrogliomas: the primitive glial and neuronal differentiation.

Oligoastrocytoma of the brain in a hooded crane (Grus monacha).

A cerebral tumor was identified at necropsy in a mature female hooded crane (Grus monacha). On gross examination, the cut surface of the tumor revealed a soft gelatinous mass. On histologic examination, the tumor was mainly composed of 2 discrete components that resembled oligodendroglioma and astrocytoma. Both components had anaplastic changes, such as pleomorphism, high proliferative activity, microvascular proliferation, and necrosis. The oligodendrogliomatous component showed a honeycomb appearance formed by the accumulation of variably sized neoplastic cells with perinuclear halos and central nuclei. The astrogliomatous component consisted of remarkably pleomorphic cells, including bizarre giant cells. Immunohistochemistry revealed that the oligodendrogliomatous component cells were partially immunoreactive for vimentin and myelin basic protein, and the astrogliomatous component cells were immunoreactive for vimentin, S-100, and glial fibrillary acidic protein. Based on these findings, the tumor was diagnosed as an oligoastrocytoma.

Anti-NMDA receptor encephalitis in Japan: long-term outcome without tumor removal.

OBJECTIVE: To report the definitive diagnosis of anti-NMDA receptor (NMDAR) encephalitis in four Japanese women previously diagnosed with "juvenile acute nonherpetic encephalitis" of unclear etiology, and to describe their long-term follow-up in the absence of tumor resection. METHODS: We extensively reviewed the case histories with current clinical and laboratory evaluations that include testing for antibodies to NR1/NR2 heteromers of the NMDAR in serum/CSF available from the time of symptom onset (4 to 7 years ago) and the present. RESULTS: All patients sequentially developed prodromal symptoms, psychosis, hypoventilation, severe orofacial dyskinesias, and bizarre immunotherapy-resistant involuntary movements that lasted 1 to 12 months. Two patients required mechanical ventilation for 6 and 9 months. Initial tests were normal or unrevealing, including the presence of nonspecific CSF pleocytosis, and normal or mild changes in brain MRI. Eventually, all patients had dramatic recovery of cognitive functions, although one had bilateral leg amputation due to systemic complications. Antibodies to NR1/NR2 heteromers were found in archived serum or CSF but not in long-term follow-up samples. An ovarian teratoma was subsequently demonstrated in three patients (all confirmed pathologically). CONCLUSION: 1) These findings indicate that "juvenile acute nonherpetic encephalitis" or a subset of this disorder is mediated by an antibody-associated immune response against NR1/NR2 heteromers of the NMDA receptor (NMDAR). 2) Our patients' clinical features emphasize that anti-NMDAR encephalitis is severe but potentially reversible and may precede by years the detection of an ovarian teratoma. 3) Although recovery may occur without tumor removal, the severity and extended duration of symptoms support tumor removal.

Hypoxia accelerates cancer invasion of hepatoma cells by upregulating MMP expression in an HIF-1alpha-independent manner.

Tumor hypoxia has been reported to induce tumor progression in several carcinomas. Current studies have shown that hypoxia inducible factor-1alpha (HIF-1alpha) is stabilized under hypoxic conditions and transactivates various genes related to cancer aggressiveness. In the present study, we examined whether hypoxia affects cancer invasion in hepatocellular carcinoma. We aimed to solve the molecular mechanism of tumor invasion under the hypoxic condition. We showed that tumor hypoxia accelerated cancer invasion in two hepatoma cell lines. Using Western blot and RT-PCR analyses we demonstrated striking evidence that the expression of HIF-1alpha, ETS-1, MMP-7 and MT1-MMP was strongly upregulated by hypoxic stimulation. To examine whether these invasion-related genes are regulated by HIF-1alpha, we treated hepatoma cells with TX-402, which was reported to repress HIF-1alpha expression. HIF-1alpha expression was strongly repressed by the TX-402 treatment. In contrast, the expression of ETS-1, MMP-7 and MT1-MMP mRNA was not affected by TX-402 treatment. We further established stable transfectants in which HIF-1alpha dominant negative vector was introduced into Hep3B cells (pHIF-1alphaDN). In the pHIF-1alphaDN cells, the expression of ETS-1, MMP-7 and MT1-MMP was not repressed. Moreover, the invasion activity of pHIF-1alphaDN was not altered, compared with that of the mock. In hepatoma cells, we provided evidence that hypoxic stress accelerates cancer invasion by upregulating ETS-1 and the MMP family by an HIF-1alpha-independent pathway.

G-Quadruplex stabilization by telomestatin induces TRF2 protein dissociation from telomeres and anaphase bridge formation accompanied by loss of the 3' telomeric overhang in cancer cells.

Inhibition of telomerase activity by telomerase inhibitors induces a gradual loss of telomeres, and this in turn causes cancer cells to enter to a crisis stage. Here, we report the telomerase inhibitor telomestatin, which is known to stabilize G-quadruplex structures at 3' single-stranded telomeric overhangs (G-tails), rapidly dissociates TRF2 from telomeres in cancer cells within a week, when given at a concentration that does not cause normal cells to die. The G-tails were dramatically reduced upon short-term treatment with the drug in cancer cell lines, but not in normal fibroblasts and epithelial cells. In addition, telomestatin also induced anaphase bridge formation in cancer cell lines. These effects of telomestatin were similar to those of dominant negative TRF2, which also causes a prompt loss of the telomeric G-tails and induces an anaphase bridge. These results indicate that telomestatin exerts its anticancer effect not only through inhibiting telomere elongation, but also by rapidly disrupting the capping function at the very ends of telomeres. Unlike conventional telomerase inhibitors that require long-term treatments, the G-quadruplex stabilizer telomestatin induced prompt cell death, and it was selectively effective in cancer cells. This study also identifies the TRF2 protein as a therapeutic target for treating many types of cancer which have the TRF2 protein at caps of the telomere DNA of each chromosome.

Establishment of human cementifying fibroma cell lines by transfection with temperature-sensitive simian virus-40 T-antigen gene and hTERT gene.

Human cementifying fibroma (HCF) is a benign fibro-osseous neoplasm of periodontal ligament (PDL) origin containing varying amounts of mineralized material resembling cementum. In the present study, we established cell lines from HCF, which were detected in the mandible of a 54-year-old Japanese man. To obtain immortalized cell clones, we undertook transfection with temperature-sensitive simian virus-40 (SV40) T-antigen and hTERT into HCF cells. Cells transfected with SV40 T-antigen entered "crisis" state between passages 22 and 35, but activation of telomerase by transfection with hTERT in the SV40-transformed HCF cells resulted in bypass of the crisis and maintenance over passage 200. HCF cell lines decreased the expression of SV40 T-antigen and the activity of cell proliferation at a nonpermissive temperature (39 degrees C) in comparison with that at a permissive temperature (33 degrees C). High activities of alkaline phosphatase and mineralization and the expression of type I collagen, osteocalcin, osteopontin, and bone sialoprotein by reverse transcription-polymerase chain reaction (RT-PCR) were observed in HCF cells at 39 degrees C. Overall, these findings suggest that: (i) HCF cell lines may represent a novel in vitro human cell model for the study of the regulatory mechanism of differentiation and proliferation of the human PDL; and (ii) transfection of plasmids encoding the temperature-sensitive SV40 T-antigen gene and hTERT gene may be useful for obtaining immortalized cell lines from benign human tumor and, probably, nonneoplastic human tissues.

Increased inactivation of nitric oxide is involved in impaired coronary flow reserve in heart failure.

Recent evidence suggests that increased inactivation of endothelium-derived nitric oxide (NO) by oxygen free radical (OFR) formation is involved in the pathogenesis of endothelial dysfunction in heart failure (HF). However, it is unclear whether increased OFR limits coronary flow reserve in HF. To test this hypothesis, we examined the effects of antioxidant therapy on coronary flow reserve in a canine model of tachycardia-induced HF. The flow reserve (percent increase in coronary blood flow) to adenosine or to 20-s ischemia was less and OFR formation (electron-spin resonance spectroscopy) in myocardial tissues was greater in HF dogs than in controls. Immunohistochemical staining of 4-hydroxy-2-nonenal, an OFR-induced lipid peroxide, was detected in coronary microvessels of HF dogs. Intracoronary infusion of a cell-permeable OFR scavenger, tiron, suppressed OFR formation and improved the vasodilating capacity to adenosine or brief ischemia in HF dogs but not in controls. A NO synthesis inhibitor, N(G)-monomethyl-L-arginine (L-NMMA), diminished the beneficial effects of tiron in HF dogs. Vasodilation to sodium nitroprusside was similar between control and HF dogs, and no change in its response was noted with tiron or tiron + L-NMMA in either group. In summary, antioxidant treatment with tiron improved coronary flow reserve by increasing NO bioactivity in HF dogs. Thus increased OFR formation may impair coronary flow reserve in HF by reducing NO bioactivity.

The mechanisms by which both heterozygous peroxisome proliferator-activated receptor gamma (PPARgamma) deficiency and PPARgamma agonist improve insulin resistance.

Peroxisome proliferator-activated receptor (PPAR) gamma is a ligand-activated transcription factor and a member of the nuclear hormone receptor superfamily that is thought to be the master regulator of fat storage; however, the relationship between PPARgamma and insulin sensitivity is highly controversial. We show here that supraphysiological activation of PPARgamma by PPARgamma agonist thiazolidinediones (TZD) markedly increases triglyceride (TG) content of white adipose tissue (WAT), thereby decreasing TG content of liver and muscle, leading to amelioration of insulin resistance at the expense of obesity. Moderate reduction of PPARgamma activity by heterozygous PPARgamma deficiency decreases TG content of WAT, skeletal muscle, and liver due to increased leptin expression and increase in fatty acid combustion and decrease in lipogenesis, thereby ameliorating high fat diet-induced obesity and insulin resistance. Moreover, although heterozygous PPARgamma deficiency and TZD have opposite effects on total WAT mass, heterozygous PPARgamma deficiency decreases lipogenesis in WAT, whereas TZD stimulate adipocyte differentiation and apoptosis, thereby both preventing adipocyte hypertrophy, which is associated with alleviation of insulin resistance presumably due to decreases in free fatty acids, and tumor necrosis factor alpha, and up-regulation of adiponectin, at least in part. We conclude that, although by different mechanisms, both heterozygous PPARgamma deficiency and PPARgamma agonist improve insulin resistance, which is associated with decreased TG content of muscle/liver and prevention of adipocyte hypertrophy.

Dietary mold oil rich in gamma linolenic acid increases insulin-dependent glucose utilization in isolated rat adipocytes.

Effects of dietary fats differing in fatty acid composition on insulin-stimulated glucose metabolism in adipocytes isolated from rat white adipose tissue were compared. Rats were fed experimental diets containing various fats differing in fatty acid composition for 7 days. In the first experiment, rats were fed palm oil mainly consisting of palmitic (45.3%) and oleic acids (39.1%) or safflower oil rich in linoleic acid (71.6%). In the second trial, rats were fed palm oil, or a fat mixture rich in linoleic acid or mold oil rich in gamma-linolenic acid. Contents of fatty acids except for linoleic and gamma-linolenic acid were comparable between the fat mixture and mold oil. The former was devoid of gamma-linolenic acid and contained 42.0% linoleic acid, while the latter contained 25.9% gamma-linolenic and 15.7% linoleic acids. In the first experiment, the insulin-dependent increase in glucose oxidation and incorporation into lipids was higher in rats fed safflower oil compared to those fed palm oil. In the second experiment, the insulin-dependent increase in glucose oxidation and incorporation into lipids was higher in rats fed the fat mixture and mold oil than in those fed palm oil. However, the extent of the increase in these parameters was much greater in rats fed mold oil than in those fed the fat mixture. Therefore, dietary gamma-linolenic acid compared to linoleic acid increases glucose metabolism in response to insulin stimuli in isolated rat adipocytes.

Long-term follow-up of interferon-treated chronic hepatitis C and serum hepatic fibrosis markers.

BACKGROUND/AIMS: We investigated the clinical application of serum fibrosis markers in a long-term follow-up of patients with chronic hepatitis C treated with interferon-alpha. METHODOLOGY: This study included 52 patients treated with interferon-alpha (total: 480 MU) for 6 months. They each underwent liver biopsy before and after treatment. Twenty-eight patients who underwent liver biopsy less than 2 years after treatment were classified as group 1, and 24 patients as group 2. The two groups were subdivided into HCV RNA-negative responders and HCV RNA-positive nonresponders. Liver specimens were estimated using grading and staging scores. Serum hyaluronan, PIIIP, and type IV collagen levels were measured before and after treatment. RESULTS: In the responders of groups 1 and 2, grading score after treatment was significantly decreased compared with that before treatment. Staging score after treatment was significantly improved only in the responders of group 2. In the responders of group 2, serum hyaluronan level was significantly decreased compared with that before treatment. In group 2, the grading score was significantly correlated with serum PIIIP and type IV collagen levels, and the staging score was significantly correlated with only serum hyaluronan level. CONCLUSIONS: These findings indicate that the serum PIIIP and type IV collagen levels reflect the activity, and serum hyaluronan reflects the degree of fibrosis in liver specimens of HCV RNA-negative patients in a long-term follow-up of patients after interferon-alpha treatment.

Clonal chromosomal aberrations accompanied by strong telomerase activity in immortalization of human B-lymphoblastoid cell lines transformed by Epstein-Barr virus.

Human B-lymphoblastoid cell lines transformed by Epstein-Barr (EBV-LCLs) are considered to be immortalized, although most of them show a normal diploid karyotype. Recently, we and others have shown that only part of EBV-LCLs is immortalized by developing strong telomerase activity that stabilizes the telomeres. In this study, we investigated the change in karyotypes during immortalization. All the eight immortalized cell lines developed clonal chromosomal aberrations accompanied by the development of strong telomerase activity. Interestingly, abnormal chromosomes were not shared among the immortalized cell lines. These results strongly suggest that chromosomal rearrangements and induction of strong telomerase activity are two events that take place in parallel in the process of immortalization of EBV-LCLs, and indicate that EBV-LCLs are clearly divided into two distinct groups, pre-immortal cell lines mostly with a normal diploid karyotype and post-immortal cell lines with a clonally abnormal karyotype.

Transcription-mediated amplification is more useful in the follow-up of patients with chronic hepatitis B treated with lamivudine.

Changes in the HBV DNA level during the treatment of patients with chronic hepatitis B with lamivudine were investigated by the transcription-mediated amplification (TMA) assay. Twenty-four patients treated with lamivudine (males:female= 20:4, age: 44.0+/-9.0 years, chronic hepatitis: 14, cirrhosis: 7, cirrhosis with hepatocellular carcinoma: 3) were investigated. The dosage of lamivudine was 75 mg/day in 3, 100 mg/day in 8, and 150 mg/day in 13 patients, and the administration period was 48+/-16 weeks (24-79 weeks). Sixteen patients were HBe antigen-positive before treatment, and the HBV DNA level was 7.4+/-1.2 (4.0- more than 8.7) LGE/ml. The HBV DNA level was measured every 1-6 months by the TMA assay and the branched DNA signal amplification technology (b-DNA assay). Serum HBV DNA disappeared in all patients by the b-DNA during the treatment period, while six patients had persistent HBV DNA by the TMA. The time of HBV DNA disappearance by the TMA in 18 patients was 2-5 months after initiation of treatment. The disappearance rate of HBV DNA was 3/8 (38%) in patients whose HBV DNA level before treatment was 8.0 LGE/ml or higher, 7/8 (88%) in those with 7-7.9 LGE/ml, and 8/8 (100%) in those with 6.9 LGE/ml or lower, showing that disappearance of HBV DNA became difficult when the HBV DNA level before treatment was high (P<0.01). In six patients, the HBV DNA level disappeared once, then increased thereafter. The present findings suggested that these increases in the HBV DNA level were due to an increase of YMDD mutant in three of these six patients, and due to a decrease in the dosage in two patients. In treatment with lamivudine, the TMA assay is more useful for understanding the changes in the HBV DNA level than b-DNA assay.

X-rays induce dose-dependent and cell cycle-independent accumulation of p21(sdi1/WAF1).

Cell cycle arrest at the G1 checkpoint is governed by a function of wild-type p53. We assessed the behavior of the sdi1 gene, which codes for a 21kDa potent inhibitor of cdk/cyclins, after X-irradiation. X-irradiation induced sdi1 mRNA accumulation and G1 arrest only in cells possessing wild-type p53. Elevation of p21(sdi1/WAF1) was preceded by p53 accumulation, which occurred despite p53 mRNA constancy in normal cells growing in the log phase. The quantity of accumulated p53 and p21(sdi1/WAF1) was radiation dose dependent. A decrease in the S phase cell population in normal cells observed after irradiation reached a minimum at less-than-maximum levels of p53 and p21(sdi1/WAF1). Furthermore, an accumulation of p53 and p21(sdi1/WAF1) was also observed when cells were synchronized in the G0, G1 and S phase and X-irradiated. These results indicated that an X-ray induced p53 and p21(sdi1/WAF1) accumulation mechanism exists throughout the cell cycle, and that the signal strength induced by X-irradiation is dose-dependent.

Dietary gamma-linolenic acid in the form of borage oil causes less body fat accumulation accompanying an increase in uncoupling protein 1 mRNA level in brown adipose tissue.

Rats were fed a low-fat diet containing 2% safflower oil or 20% fat diets containing either safflower oil rich in linoleic acid, borage oil containing 25% gamma (gamma)-linolenic acid or enzymatically prepared gamma-linolenic acid enriched borage oil containing 47% gamma-linolenic acid for 14 days. Energy intake and growth of animals were the same among groups. A high safflower oil diet compared with a low-fat diet caused significant increases in both epididymal and perirenal white adipose tissue weights. However, high-fat diets rich in gamma-linolenic acid failed to do so. Compared with a low-fat diet, all the high-fat diets increased mRNA levels of uncoupling protein 1 and lipoprotein lipase in brown adipose tissue. The extents of the increase were greater with high-fat diets rich in gamma-linolenic acid. Various high-fat diets, compared with a low-fat diet, decreased glucose transporter 4 mRNA in white adipose tissue to the same levels. The amount and types of dietary fat did not affect the leptin mRNA level in epididymal white adipose tissue. However, a high safflower oil diet, but not high-fat diets rich in gamma-linolenic acid relative to a low-fat diet, increased perirenal white adipose tissue leptin mRNA levels. All high-fat diets, relative to a low-fat diet, increased the hepatic mitochondrial fatty acid oxidation rate and fatty acid oxidation enzyme mRNA abundances to the same levels. High-fat diets also increased these parameters in the peroxisomal pathway, and the increases were greater with high-fat diets rich in gamma-linolenic acid. The physiological activity in increasing brown adipose tissue gene expression and peroxisomal fatty acid oxidation was similar between the two types of borage oil differing in gamma-linolenic acid content. It was suggested that dietary gamma-linolenic acid attenuates body fat accumulation through the increase in gene expressions of uncoupling protein 1 in brown adipose tissue. An increase in hepatic peroxisomal fatty acid oxidation may also contribute to the physiological activity of gamma-linolenic acid in decreasing body fat mass.

Differential regulation of human RecQ family helicases in cell transformation and cell cycle.

Three human RecQ DNA helicases, WRN, BLM and RTS, are involved in the genetic disorders associated with genomic instability and a high incidence of cancer. RecQL1 and RecQL5 also belong to the human RecQ helicase family, but their correlation with genetic disorders, if any, is unknown. We report here that in human B cells transformed by Epstein-Barr virus (EBV), human fibroblasts and umbilical endothelial cells transformed by simian virus 40, the expression of WRN, BLM, RTS and RecQL1 was sharply up-regulated. In B cells this expression was stimulated within 5-40 h by the tumor promoting agent phorbol myristic acetate (PMA). Interestingly, RecQL5beta, an alternative splicing product of RecQL5 with a nuclear localization signal, is expressed in resting B cells without significant modulation of its synthesis by EBV or PMA, suggesting it has a role in resting cells. We also roughly determined the number of copies per cell for the five RecQ helicase in B cells. In addition, levels of the different RecQ helicases are modulated in different ways during the cell cycle of actively proliferating fibroblasts and umbilical endothelial cells. Our results support the view that the levels of WRN, BLM, RTS and RecQL1 are differentially up-regulated to guarantee genomic stability in cells that are transformed or actively proliferating.