The role of HER3 on HER2-driven gallbladder carcinogenesis and possible HER2/HER3 targeting therapy by pertuzumab for gallbladder canrcinoma

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Background: ErbB2 has been known to be important for gallbladder carcinogenesis. Supporting this, the gene amplification of HER2 was found in ca. 20% of human gallbladder carcinoma (GBC) (Kawamoto, et al. Gastrointest Cancer Res 2007). Following these results, a Phase II study of trastuzumab for treatment of GBC (NSC 688097) is being conducted. Although the mechanism of HER2 activation is not well understood, the role of HER3 in HER2-driven tumorigenesis has been discussed and we have concluded that HER2/HER3 heterodimerization might be important for GBC cell proliferation (ASCOGI 2009, ab#155). In this study, we determined HER family expressions in human GBC and examined the effect of pertuzumab against human GBC cell lines. Methods: Tissues from 47 GBCs and 6 non-cancerous gallbladders were examined. All cases were screened for HER1, HER2, HER3 expressions by immunohistochemistry (IHC) and those HER family gene amplification by fluorescence in situ hybridization (FISH) were performed. 6 human GBC cell lines were also analyzed by Western blotting and FISH as well and their growth assays were investigated with heregulin stimulation to confirm the existence of HER2/HER3 heterodimerization. Then, GBC cells were cultured with heregulin and various doses of pertuzumab for 72 hours and CCK-8 assay was performed. Results: HER3, HER2 and HER1 overexpression by IHC was found in 34%, 32% and 19% of GBCs, respectively. Phosphorylated (p-) HER2 and p-HER1 were found in 23% and 11% of GBCs, respectively. FISH analysis was considered successful in the same serial sections. HER3, HER2 and HER1 FISH (+) was found in 26%, 19% and 4% of GBCs, respectively. Three of 6 GBC cell lines were recognized their growth curves with heregulin were increasing. These 3 cell lines showed good responses to the treatment with pertuzumab. Conclusions: More than 20% of GBC over-expressed either HER2 or HER3. These HER2 and HER3 may form heterodimer, which in turn results in the activation of HER2. The cell lines proliferating with the administration of heregulin showed good responses to the pertuzumab treatment. Therefore, HER2/HER3 heterodimerization may be an ideal biomarker for the treatment by pertuzumab and this agent may be a new therapeutic regimen for GBC.

No significant financial relationships to disclose.

Chronic (-)-hydroxycitrate administration spares carbohydrate utilization and promotes lipid oxidation during exercise in mice

(-)-Hydroxycitrate (HCA) is an active ingredient that is extracted from the rind of the Indian fruit, Garcinia cambogia, which is available as an herbal supplement and is used to lose weight. In this study, the acute and chronic effects of HCA on energy metabolism were examined in male Std ddY mice. Mice were placed into metabolic chambers and administered 10 mg HCA or water (control) orally. Serum free fatty acid levels were significantly higher 100 min after administration in the HCA group, but the respiratory exchange ratio was not different from that in the control group. The concentration of glycogen in the gastrocnemius muscle was higher in the HCA group 16 h after administration, and in a separate study, the maximum swimming time until fatigue was slightly longer (P: = 0. 21) than that in the control group on d 1. The difference was significant on d 3 after 3 d of HCA or water administration. Other mice were administered 10 mg HCA or water orally twice a day for 25 d. On d 26, they were placed into metabolic chambers after administration and allowed to rest for 1 h, followed by 1 h of running at 15 m/min. Respiratory gas was monitored. The respiratory exchange ratio was significantly lower in the HCA group during both resting and exercising conditions. These results suggest that chronic administration of HCA promotes lipid oxidation and spares carbohydrate utilization in mice at rest and during running.

Gallstones in patients with rheumatoid arthritis

OBJECTIVE

We performed abdominal ultrasonography (US) on patients with rheumatoid arthritis (RA) to investigate the frequency and characteristics of gallstones (GS).

METHODS

Patients with RA (n = 224; 42 male and 182 female) underwent abdominal US.

RESULTS

The incidence of GS (including post-chorecystectomy patients) was significantly higher in female patients with RA (15.4%) than in female controls (5.2%, p < 0.01). There was no significant difference in GS incidence between male patients with RA (9.5%) and male controls (3.8%). The percentage of cholesterol stones was 100% in patients with RA with GS but only 66.7% in controls with GS (p < 0.01). Compared to patients with RA without GS, patients with RA with GS were older and had lower C-reactive protein levels, a decreased creatinine clearance and urinary calcium excretion, and an increased incidence of hypercholesterolemia.

CONCLUSION

We observed a high incidence of GS in female patients with RA. With our previous observation of a high incidence of renal stones in patients with RA, these results suggest the importance of US as a diagnostic tool in the management of RA.

Increased 9,13-di-cis-retinoic acid in rat hepatic fibrosis: implication for a potential link between retinoid loss and TGF-beta mediated fibrogenesis in vivo

BACKGROUND/AIMS

During hepatic fibrosis, hepatic stellate cells (HSCs) transform into myofibroblastic cells and lose their intracellular droplets of retinyl esters, the storage form of vitamin A. Recently, we have demonstrated that 9,13-di-cis-retinoic acid (RA), a geometric isomer identified as a stable and major metabolite of vitamin A in circulation, stimulates the synthesis of plasminogen activator (PA) and induces PA/plasmin-dependent latent transforming growth factor (TGF)-beta activation in HSC cultures, probably via induction and activation of RA receptor (RAR) alpha. The aim of the present study was to address a potential link between the loss of retinyl esters to increased formation of RA(s), which might play a role in facilitating TGF-beta-mediated liver fibrogenesis in vivo.

METHODS

We examined the effect of 9,13-di-cis-RA on transactivating activity of RARalpha in HeLa cells as well as its effect on PA- and TGF-beta-dependent collagen synthesis in rat and human HSC cultures. We measured the changes in 9,13-di-cis-RA levels both during activation of rat HSCs in vitro and during porcine serum-induced rat hepatic fibrosis in vivo and correlated this with RAR alpha/beta, PA, TGF-beta and type I procollagen mRNA expression in the fibrotic liver.

RESULTS

9,13-di-cis-RA transactivated RARalpha, and provoked PA/plasmin and TGF-beta-dependent procollagen synthesis in HSCs. 9,13-di-cis-RA levels were increased both in activated HSCs in vitro and in fibrotic liver accompanying the enhanced expression of RAR alpha/beta, PA, TGF-beta and procollagen in vivo.

CONCLUSIONS

These findings suggest a potential link between 9,13-di-cis RA formation and hepatic fibrosis via formation of TGF-beta in vivo, and thus provide further insight into the biologic role of retinoids during hepatic fibrogenesis.

[Randomized controlled trial of MMC + UFT and MMC + 5-FU therapy in advanced gastric cancer]

To compare the effects of MMC + UFT (A) with MMC + 5-FU (B) therapy on the response rate, survival time and changes with time in quality of life (QOL) in unresectable or recurrent gastric cancer, we carried out a study by a multicenter, randomized controlled trial from June 1990 to August 1992. 39 patients were randomly divided into A group and B group, including 6 incompletely evaluated cases and 3 in eligible cases. Responses were recognized in 3 out of 13 evaluable cases (23.1%) treated with regimen A and in one out of 15 evaluable cases (6.7%) treated with regimen B. Mean survival time was 150 days (A) and 116 days (B), respectively. These results suggested that MMC + UFT therapy is one of the effective regimens for advanced gastric cancer and as useful as MMC + 5-FU therapy. Moreover, it showed that regimen A was superior to B on QOL.

[Methicillin-resistant Staphylococcus aureus (MRSA) isolated in hospitals in Fukuoka City area]

Bacteriological and clinical studies were carried out on 280 strains of Staphylococcus aureus isolated in hospitals in Fukuoka city area from September 1990 to March 1991. Of all S. aureus strains studied 116 (41.4%) were methicillin-resistant. The proportion of MRSA in S. aureus isolates from outpatients was 10% (11/109), 69.2% (90/130) in those from inpatients. The average age of patients with isolated MRSA was 70.5 +/- 16.9 years and that of patients with isolated MSSA, 44.2 +/- 29.3. MRSA strains were recovered mainly from sputum and pus. The isolation rate did not vary significantly with hospitals of different size (number of beds). Of all MRSA strains 48 (41.3%) produced coagulase type VII. As for drug susceptibility, MRSA strains with coagulase type VII were more sensitive to clindamycin and more resistant to minocyclin compared to MRSA with other coagulase types.

Imipenem/cilastatin as secondary therapy for bacterial infections

Imipenem/cilastatin (IPM/CS) was used to treat 39 documented infections in patients who had failed to respond to other antibiotic regimens. The overall response rating was 76.9%. Respiratory infections responded less frequently (efficacy rating, 55.6%) to IPM/CS than abdominal infections, urinary tract infections, or sepsis. Methicillin-resistant Staphylococcus aureus, Xanthomonas maltophilia, and Acinetobacter calcoaceticus were less sensitive to IPM/CS therapy than the other bacterial strains encountered. Respiratory tract infections were though to be less responsive to IPM/CS, probably because imipenem-resistant strains of S aureus were present in most of those cases. It is concluded that IPM/CS is well tolerated and effective in the treatment of various bacterial infections.