Xiao-Tang Kong

p53 Mutants Have Selective Dominant-Negative Effects on Apoptosis but Not Growth Arrest in Human Cancer Cell Lines

ABSTRACT A bidirectional expression vector that allowed equal transcription of cloned wild-type and mutant p53 cDNAs from the same vector was developed. The vector was transfected into CaLu 6 lung carcinoma cells or Saos-2 osteosarcoma cells. All p53 mutants examined were recessive to wild-type p53 transactivation ofp21WAF1/CIP1 but dominant-negative for transactivation of Bax. An examination of effects on growth arrest and apoptotic pathways indicated that all mutants were recessive to wild type for growth arrest but only three of seven mutants were dominant negative for induction of apoptosis.

Treatment of acute bronchiolitis with Chinese herbs.

In a randomised single blind trial the Chinese herbs Shuang Huang Lian were evaluated for the treatment of acute bronchiolitis. Children with acute bronchiolitis and serological evidence of recent respiratory syncytial virus infection were studied in a tertiary hospital in Harbin, China. The 96 children were randomised into three treatment groups: herbs, herbs with antibiotics, and antibiotics alone. The herbs were prepared by the medical school pharmacy and administered daily by intravenous infusion for seven days. The main outcomes, assessed blindly, were symptomatic improvement in cough, fever, wheezing, chest signs, and duration of stay in hospital. The mean duration of symptoms from the start of treatment was 6.2 (confidence interval 5.6 to 6.9) days in the two groups treated with herbs compared with 8.6 (confidence interval 7.5 to 9.8) days in the group treated with antibiotics alone. The mean reductions in duration of clinical manifestations for treatment with antibiotics alone compared with herbs were: from 3.1 to 1.5 days for fever, 9.1 to 6.1 days for cough, 6.5 to 4.1 days for wheezing, and 7.2 to 4.9 days for chest crackles. No adverse effect of Shuang Huang Lian herbal treatment was detected. In conclusion, this study confirms Chinese experience with Shuang Huang Lian that it is safe and effective, and warrants further study.

Big Potassium (BK) ion channels in biology, disease and possible targets for cancer immunotherapy

The Big Potassium (BK) ion channel is commonly known by a variety of names (Maxi-K, KCNMA1, slo, stretch-activated potassium channel, KCa1.1). Each name reflects a different physical property displayed by this single ion channel. This transmembrane channel is found on nearly every cell type of the body and has its own distinctive roles for that tissue type. The BKα channel contains the pore that releases potassium ions from intracellular stores. This ion channel is found on the cell membrane, endoplasmic reticulum, Golgi and mitochondria. Complex splicing pathways produce different isoforms. The BKα channels can be phosphorylated, palmitoylated and myristylated. BK is composed of a homo-tetramer that interacts with β and γ chains. These accessory proteins provide a further modulating effect on the functions of BKα channels. BK channels play important roles in cell division and migration. In this review, we will focus on the biology of the BK channel, especially its role, and its immune response towards cancer. Recent proteomic studies have linked BK channels with various proteins. Some of these interactions offer further insight into the role that BK channels have with cancers, especially with brain tumors. This review shows that BK channels have a complex interplay with intracellular components of cancer cells and still have plenty of secrets to be discovered.

Alterations of the Tumour Suppressor Gene DCC in Neuroblastoma

The deleted in colorectal carcinoma (DCC) gene, a candidate tumour suppressor, might be inactivated in a number of human cancers. In order to evaluate the possible role of DCC alterations in the pathogenesis of neuroblastoma, we examined 25 neuroblastoma cell lines and 16 primary tumours, including 6 samples with loss of heterozygosity (LOH) at the DCC locus for DCC mRNA expression, by using the reverse transcriptase-polymerase chain reaction (RT-PCR) technique. The level of DCC expression was significantly reduced or undetectable in 12 of 25 (48%) cell lines and 7 of 16 (44%) primary tumours, suggesting that inactivation of the DCC gene is involved in the development of neuroblastoma. Three of the 6 tumours with LOH at the DCC locus revealed reduced DCC mRNA expression, indicating that LOH at the DCC locus might have affected the levels of DCC mRNA. We also screened for mutations in 4 exons of the DCC gene in 12 cell lines by using PCR-single strand conformation polymorphism (PCR-SSCP) analysis. Point mutations were not found except a polymorphic change at codon 201. The mechanism for inactivation of the DCC gene will be further investigated.

Therapeutic Immunization against Glioblastoma

Glioblastoma is the most common form of brain cancer in adults that produces severe damage to the brain leading to a very poor survival prognosis. The standard of care for glioblastoma is usually surgery, as well as radiotherapy followed by systemic temozolomide chemotherapy, resulting in a median survival time of about 12 to 15 months. Despite these therapeutic efforts, the tumor returns in the vast majority of patients. When relapsing, statistics suggest an imminent death dependent on the size of the tumor, the Karnofsky Performance Status, and the tumor localization. Following the standard of care, the administration of Bevacizumab, inhibiting the growth of the tumor vasculature, is an approved medicinal treatment option approved in the United States, but not in the European Union, as well as the recently approved alternating electric fields (AEFs) generator NovoTTF/Optune. However, it is clear that regardless of the current treatment regimens, glioma patients continue to have dismal prognosis and novel treatments are urgently needed. Here, we describe different approaches of recently developed therapeutic glioma brain cancer vaccines, which stimulate the patient’s immune system to recognize tumor-associated antigens (TAA) on cancer cells, aiming to instruct the immune system to eventually attack and destroy the brain tumor cells, with minimal bystander damage to normal brain cells. These distinct immunotherapies may target particular glioma TAAs which are molecularly defined, but they may also target broad patient-derived tumor antigen preparations intentionally evoking a very broad polyclonal antitumor immune stimulation.

The use of intravitreal rituximab in conjunction with systemic temozolomide and intravenous rituximab for the treatment of primary intraocular lymphoma

Abstract Primary intraocular lymphoma (PIOL) is rare malignancy affecting the eyes. It is a type of B cell malignancy, although T-cell type PIOL has been reported. PIOL is closely associated with primary CNS lymphoma (PCNSL). As many as