TOP2A amplification in the absence of that of HER-2/neu: toward individualization of chemotherapeutic practice in breast cancer.

PRIMARY OBJECTIVE: To investigate the relationship between human epidermal growth factor receptor (HER)-2/neu and the gene encoding topoisomerase IIα (TOP2A) in breast cancer, while elucidating their association with clinicopathological variables. METHODS: Real-time quantitative polymerase chain reaction (RQ-PCR) was performed on a 96-patient study group to assess gene amplification, and levels were determined using the comparative cycle threshold approach and Taqman assays. An immunohistochemistry (IHC) microarray (n = 76) was then employed to check for correlation between gene amplification and protein expression levels. RESULTS: Amplification levels of TOP2A did not differ significantly according to HER-2/neu status by either RQ-PCR or IHC microarray. Of the HER-2/neu(-) patients, 29.1% demonstrated levels of TOP2A above the third quartile, whereas 22.9% of the HER-2/neu(+) patients had values in the first quartile (log TOP2A <0.62), thereby indicating low-level amplification. Of the 60 patients characterized as HER-2/neu(-) using IHC and fluorescence in situ hybridization (FISH), 22.9% were classified as TOP2A(+) on the IHC microarray. Of the 14 patients deemed HER-2/neu(+) using IHC and FISH, meanwhile, the majority (n = 10) were classified as TOP2A(+). CONCLUSIONS: Our results indicate that amplification of TOP2A in breast cancer is not confined to those who are concomitantly HER-2/neu(+), and suggest that a significant proportion of HER-2/neu(-) patients exhibit high levels of TOP2A.

Expression levels of HER2/neu and those of collocated genes at 17q12-21, in breast cancer.

HER2/neu is associated with poorer clinical outcome in breast cancer. Expression patterns of co-localised cancer-associated genes at 17q12-21 were examined using RT-PCR. The study group consisted of a 96-patient cohort. Relative quantity of mRNA expression was calculated using the comparative cycle threshold method and Qbase software. Results were analysed to detect expression patterns among the genes, and to identify associations between expression levels and clinical data. Levels of HER2/neu correlated with those of GRB7 (r=0.551, p<0.001), RARA (r=0.391, p<0.001), RPL19 (r=0.549, p<0.001) and LASP1 (r=0.399, p<0.001). GRB7 was significantly inversely associated with improved DFS at 60 months (p=0.036). RARA levels were greater in HER2/neu-positive as opposed to HER2/neu-negative patients (p=0.021); levels were significantly higher in ER-positive patients, relative to those who were ER-negative (p=0.003). Levels of RPL19 were significantly higher in the HER2/neu-overexpressing (p=0.010) and luminal B subtypes (p=0.007). LASP1 levels were higher in those patients who had been classified clinically as HER2/neu-positive (p=0.004). This study reaffirms the correlation between HER2/neu and the co-localised LASP1 and GRB7; the latter target may hold additional significance in addition to being a surrogate marker for HER2/neu expression. The relationship identified between RARA and ER-positivity may herald an avenue for targeted therapy of these tumours.

Primary splenic lymphoma presenting with ascites.

An 84 year-old gentleman presented with abdominal distension, anorexia and occasional epigastric pain over a four-week period. Blood parameters revealed a hypochromic microcytic anaemia. Both CT and US scan identified ascites and a mass in the left upper quadrant. An ascitic tap was performed identifying bloody ascites and the presence of reactive mesothelial cells on cytology. A subsequent laparotomy and splenectomy was performed. Histology of the resected spleen revealed a Grade 2 follicular lymphoma (Figure 2). The patient had an uneventful postoperative recovery and was well at 6 months follow up. The spleen is an organ with an important immunological function. Primary splenic involvement occurs in less than 1% of non-hodgkin's lymphoma. Symptoms of primary splenic lymphoma (PSL) include pyrexia, weight-loss, night sweats, generalised weakness and left upper quadrant pain secondary to spleno - megaly. Ascites is a rare presenting feature of PSL. This report illustrates a case of primary splenic lymphoma which poses diagnostic challenges for the pathologist and clinician and ultimately requires definitive splenectomy to confirm a diagnosis.Figure 2Photograph of histology slide displaying the lymphoma at 10× magnification.

The xc- cystine/glutamate antiporter as a potential therapeutic target for small-cell lung cancer: use of sulfasalazine.

PURPOSE: To determine whether the xc- cystine transporter could be a useful therapeutic target for small-cell lung cancer (SCLC). METHODS: Human SCLC cell cultures were examined for growth dependence on extracellular cystine, xc- expression, glutathione levels and response to highly specific xc- inhibitors, i.e., monosodium glutamate (MSG) and the anti-inflammatory drug, sulfasalazine (SASP). In studying tumor growth inhibition by SASP, use was also made of a novel SCLC tissue xenograft model, LU6-SCLC, derived from a chemoresistant patient's SCLC specimen. RESULTS: Growth of NCI-H69 and NCI-H82 SCLC cells greatly depended on xc- -mediated uptake of cystine. SASP substantially reduced their glutathione levels (>70%; 0.3 mM SASP; 24 h) and growth (72 h) with IC(50)s of 0.21 and 0.13 mM, respectively; MSG also inhibited growth markedly. Both SASP- and MSG-induced growth arrests were largely prevented by cystine uptake-enhancing 2-mercaptoethanol (66 approximately microM) indicating they were primarily due to cystine starvation. Without major side-effects, SASP (i.p.) restrained growth of NCI-H69 cell xenografts (approximately 50%) and, importantly, substantially inhibited growth of the clinically more relevant LU6-SCLC tissue xenografts (approximately 70% by stereological analysis), reducing tumor glutathione contents. CONCLUSIONS: The xc- cystine/glutamate antiporter is potentially useful as a target for therapy of SCLC based on glutathione depletion. Sulfasalazine may be readily used for this approach, especially in combination chemotherapy.