Hepatic arterial infusion chemotherapy in the treatment of advanced hepatocellular carcinoma with portal vein thrombosis: a case-control study

AIM

To study the treatment efficacy and survival of hepatic arterial infusion chemotherapy (HAIC) for patients with advanced hepatocellular carcinoma (HCC) and portal vein tumour thrombosis (PVTT) with compensated cirrhosis in comparison with sorafenib as the standard of care therapy versus best supportive care (BSC).

MATERIALS AND METHODS

This case-control study included 91 patients with advanced HCC and PVTT divided into three groups: Group 1 20 treated with HAIC, (50 mg adriamycin and 50 mg cisplatin were infused in hepatic artery); Group 2, 42 patients treated with BSC; and Group 3, 29 patients treated with sorafenib. Patients were followed up for assessment and comparison of treatment outcome by modified Response Evaluation Criteria in Solid Tumours (mRECIST) and survival.

RESULTS

There was no significant difference among the groups studied regarding baseline demographic and tumour characteristics. The majority of patients who received sorafenib therapy (82.8%) had stable disease. The response rate (complete response + partial response) was significantly better in the HAIC group. HAIC patients had the longest survival compared with the best supportive care and sorafenib groups, which was statistically significant (29.2 ± 21.8, 4.55 ± 11.41, and 11.52 ± 8.72 months respectively, p=0.007) CONCLUSION: HAIC is a safe procedure with a better response rate and longer survival than best supportive care or sorafenib for patients with advanced HCC and PVTT.

Facial hyperpigmentation during imatinib therapy for gastrointestinal stromal tumor

We report a rare case of facial hyperpigmentation during imatinib therapy for a gastrointestinal stromal tumor.

The initial experience of safety and efficacy of argon plasma coagulation (APC) in the primary prevention of variceal bleeding

BACKGROUND AND STUDY AIMS

The well-known complications of variceal bleeding together with the high mortality rate mandate effective prophylaxis. Because of the intolerance, failure of response and lack of compliance related to B blockers and because of the high incidence of variceal recurrence after endoscopic variceal ligation (EVL), other alternatives should be investigated. As APC provides coagulation at a shallow depth, it has been considered an ideal procedure to promote mucosal fibrosis for oesophageal varices. This study aims to investigate the safety and effectiveness of APC application to the oesophagus post-variceal obliteration in an attempt to decrease variceal recurrence and bleeding, as compared to EVL.

PATIENTS AND METHODS

This study included 60 patients with chronic liver disease and portal hypertension referred to the Gastrointestinal Endoscopy Unit, Kasr Al-Aini Hospital, Cairo University, during the period from August 2008 till January 2010. Patients had to have large-sized varices (F3), without history of bleeding, portal hypotensive drugs or intervention. Patients were allocated into either group I that included 30 patients for whom EVL was performed and sequentially followed by one session of APC or group II that included 30 patients for whom EVL alone was done. Patients underwent surveillance endoscopy at 3 and 6months to evaluate variceal recurrence (F1 or more).

RESULTS

Both groups were comparable in terms of the demographic features, hepatic functional reserve and endoscopic findings. Post-APC, fever was reported in 6.7%, dysphagia in 3.3%, procedure-related bleeding in 0% and stricture in 3.3%. At 3 and 6months follow-up, both groups were comparable in terms of variceal recurrence and none of the patients in both groups developed variceal bleeding.

CONCLUSION

Although, APC application to the oesophageal mucosa is a safe technique, its additive benefit in terms of variceal recurrence and re-bleeding is comparable to EVL alone. This is encountered when only a single session of APC is applied. A more beneficial effect of multiple sessions of APC awaits further studies.

The metallochaperone Atox1 plays a critical role in perinatal copper homeostasis

Copper plays a fundamental role in the biochemistry of all aerobic organisms. The delivery of this metal to specific intracellular targets is mediated by metallochaperones. To elucidate the role of the metallochaperone Atox1, we analyzed mice with a disruption of the Atox1 locus. Atox1(-/-) mice failed to thrive immediately after birth, with 45% of pups dying before weaning. Surviving animals exhibited growth failure, skin laxity, hypopigmentation, and seizures because of perinatal copper deficiency. Maternal Atox1 deficiency markedly increased the severity of Atox1(-/-) phenotype, resulting in increased perinatal mortality as well as severe growth retardation and congenital malformations among surviving Atox1(-/-) progeny. Furthermore, Atox1-deficient cells accumulated high levels of intracellular copper, and metabolic studies indicated that this defect was because of impaired cellular copper efflux. Taken together, these data reveal a direct role for Atox1 in trafficking of intracellular copper to the secretory pathway of mammalian cells and demonstrate that this metallochaperone plays a critical role in perinatal copper homeostasis.

Structure, expression, and chromosomal localization of the mouse Atox1 gene

Copper trafficking in eukaryotes involves small proteins termed metallochaperones, which mediate copper delivery to specific intracellular sites. Previous studies in yeast and human cell lines have suggested that Atox1 plays a critical role in copper delivery to the secretory pathway. In the present study, a mouse Atox1 (mAtox1) cDNA was cloned and shown to encode an open reading frame with 85% amino acid identity to human Atox1. RNA blot analysis revealed that mAtox1 was expressed as a single transcript in multiple tissues, and immunoblotting indicated that the relative abundance of mAtox1 mRNA directly correlated with mAtox1 protein. Analysis of the mAtox1 gene locus revealed a genomic structure with four exons encompassing a total of 14.5 kb. RFLP and haplotype analyses indicated that the mAtox1 locus was tightly linked to the Trhr and D15Bir7 loci on mouse chromosome 15. Taken together, these data reveal marked evolutionary conservation of Atox1 structure and provide a genomic organization and localization that will aid in the genetic deciphering of the molecular role of this protein in copper homeostasis.

Interaction of the copper chaperone HAH1 with the Wilson disease protein is essential for copper homeostasis

The delivery of copper to specific sites within the cell is mediated by distinct intracellular carrier proteins termed copper chaperones. Previous studies in Saccharomyces cerevisiae suggested that the human copper chaperone HAH1 may play a role in copper trafficking to the secretory pathway of the cell. In this current study, HAH1 was detected in lysates from multiple human cell lines and tissues as a single-chain protein distributed throughout the cytoplasm and nucleus. Studies with a glutathione S-transferase-HAH1 fusion protein demonstrated direct protein-protein interaction between HAH1 and the Wilson disease protein, which required the cysteine copper ligands in the amino terminus of HAH1. Consistent with these in vitro observations, coimmunoprecipitation experiments revealed that HAH1 interacts with both the Wilson and Menkes proteins in vivo and that this interaction depends on available copper. When these studies were repeated utilizing three disease-associated mutations in the amino terminus of the Wilson protein, a marked diminution in HAH1 interaction was observed, suggesting that impaired copper delivery by HAH1 constitutes the molecular basis of Wilson disease in patients harboring these mutations. Taken together, these data provide a mechanism for the function of HAH1 as a copper chaperone in mammalian cells and demonstrate that this protein is essential for copper homeostasis.

Heme is an effector molecule for iron-dependent degradation of the bacterial iron response regulator (Irr) protein

The bacterial iron response regulator (Irr) protein mediates iron-dependent regulation of heme biosynthesis. Pulse-chase and immunoprecipitation experiments showed that Irr degraded in response to 6 microM iron with a half-life of approximately 30 min and that this regulated stability was the principal determinant of control by iron. Irr contains a heme regulatory motif (HRM) near its amino terminus. A role for heme in regulation was implicated by the retention of Irr in heme synthesis mutants in the presence of iron. Addition of heme to low iron (0.3 microM) cultures was sufficient for the disappearance of Irr in cells of the wild-type and heme mutant strains. Spectral and binding analyses of purified recombinant Irr showed that the protein bound heme with high affinity and caused a blue shift in the absorption spectrum of heme to a shorter wavelength. A Cys(29) --> Ala substitution within the HRM of Irr (IrrC29A) abrogated both high affinity binding to heme and the spectral blue shift. In vivo turnover experiments showed that, unlike wild-type Irr, IrrC29A was stable in the presence of iron. We conclude that iron-dependent degradation of Irr involves direct binding of heme to the protein at the HRM. The findings implicate a regulatory role for heme in protein degradation and provide direct evidence for a functional HRM in a prokaryote.

Identification of a functional fur gene in Bradyrhizobium japonicum

The recent identification of the iron response regulator (Irr) in Bradyrhizobium japonicum raised the question of whether the global regulator Fur is present in that organism. A fur gene homolog was isolated by the functional complementation of an Escherichia coli fur mutant. The B. japonicum Fur bound to a Fur box DNA element in vitro, and a fur mutant grown in iron-replete medium was derepressed for iron uptake activity. Thus, B. japonicum expresses at least two regulators of iron metabolism.

The bacterial irr protein is required for coordination of heme biosynthesis with iron availability

Heme is a ubiquitous macromolecule that serves as the active group of proteins involved in many cellular processes. The multienzyme pathway for heme formation culminates with the insertion of iron into a protoporphyrin ring. The cytotoxicity of porphyrins suggests the need for coordination of its biosynthesis with iron availability. We isolated a mutant strain of the bacterium Bradyrhizobium japonicum that, under iron limitation, accumulated protoporphyrin and showed aberrantly high expression of hemB, an iron-regulated gene encoding the heme synthesis enzyme delta-aminolevulinic acid dehydratase. The strain carries a loss of function mutation in irr, a newly described gene that encodes a putative member of the GntR family of bacterial transcriptional regulators. Irr accumulated only under iron limitation, and turned over rapidly upon an increase in iron availability. A separate role for Irr in controlling the cellular iron level was inferred based on a deficiency in high affinity iron transport activity in the irr strain, and suggests that regulation of the heme pathway is coordinated with iron homeostasis. A high level of protoporphyrin accumulation is not a normal consequence of nutritional iron deprivation, thus a mechanism for iron-dependent control of heme biosynthesis may be present in other organisms.