KCa3.1 channels are involved in the infiltrative behavior of glioblastoma in vivo.

Glioblastoma multiforme (GBM) is a diffuse brain tumor characterized by high infiltration in the brain parenchyma rendering the tumor difficult to eradicate by neurosurgery. Efforts to identify molecular targets involved in the invasive behavior of GBM suggested ion channel inhibition as a promising therapeutic approach. To determine if the Ca(2+)-dependent K(+) channel KCa3.1 could represent a key element for GBM brain infiltration, human GL-15 cells were xenografted into the brain of SCID mice that were then treated with the specific KCa3.1 blocker TRAM-34 (1-((2-chlorophenyl) (diphenyl)methyl)-1H-pyrazole). After 5 weeks of treatment, immunofluorescence analyses of cerebral slices revealed reduced tumor infiltration and astrogliosis surrounding the tumor, compared with untreated mice. Significant reduction of tumor infiltration was also observed in the brain of mice transplanted with KCa3.1-silenced GL-15 cells, indicating a direct effect of TRAM-34 on GBM-expressed KCa3.1 channels. As KCa3.1 channels are also expressed on microglia, we investigated the effects of TRAM-34 on microglia activation in GL-15 transplanted mice and found a reduction of CD68 staining in treated mice. Similar results were observed in vitro where TRAM-34 reduced both phagocytosis and chemotactic activity of primary microglia exposed to GBM-conditioned medium. Taken together, these results indicate that KCa3.1 activity has an important role in GBM invasiveness in vivo and that its inhibition directly affects glioma cell migration and reduces astrocytosis and microglia activation in response to tumor-released factors. KCa3.1 channel inhibition therefore constitutes a potential novel therapeutic approach to reduce GBM spreading into the surrounding tissue.

Sentinel lymph node in patients with rectal cancer invading the anal canal.

BACKGROUND: To assess the feasibility of the sentinel lymph node procedure in patients with rectal cancer extending to the anal canal. METHODS: Between January 2005 and April 2008, 15 patients with adenocarcinoma of the rectum with direct invasion of the anal canal and no clinical evidence of inguinal involvement were prospectively enrolled in the study. The sentinel node procedure consisted of a combination of preoperative radiocolloid lymphoscintigraphy and intraoperative detection of the inguinal sentinel node with a gamma probe. Patent blue dye was also used to facilitate direct identification of the blue-stained lymph node. After removal, the sentinel node was studied by hematoxylin-eosin staining and immunohistochemistry. RESULTS: Detection and removal of inguinal sentinel nodes was possible in all patients. Four patients (26.7%) had sentinel nodes identified as positive for metastatic adenocarcinoma. All positive cases also had metastases detected in perirectal lymph nodes; three of them developed hepatic or pulmonary metastases within 6 months after surgery. Of the 11 patients with negative sentinel nodes, only four (36.4%) also presented metastatic perirectal lymph nodes. Although none of the negative cases developed late inguinal metastases, three developed systemic or pelvic recurrence within 12 months after surgery. CONCLUSIONS: The standardized procedure was highly effective in sampling inguinal sentinel nodes in very low rectal cancers, allowing the detection of subclinical metastatic disease. Although this technique can be potentially useful for a subgroup of patients with isolated inguinal metastases, it cannot be routinely recommended for patients with rectal tumors invading the anal canal at this moment.

Evidence for an association of human papillomavirus infection and colorectal cancer.

AIM: To investigate the presence of human papillomavirus (HPV) in colorectal carcinomas and the correlation of the viral infection with prognostic factors for the disease outcome. METHODS: Seventy-two patients with primary colorectal adenocarcinoma were studied. From each patient two tissue samples were collected: one sample of the tumor and one sample of normal colorectal tissue from an area located 15 cm away from the tumor. Samples of colorectal mucosa obtained from 30 individuals without malignant disease were also studied as control group. Tissues were initially analyzed through MY/GP nested polymerase chain reaction (PCR) and through GP5+/GP6+ auto-nested PCR. Specific primer sets targeting the E6/E7 region of the HPVs 6, 11, 16, 18, 31, 33, 45 were used for typing. Direct DNA sequencing was conducted to confirm positive PCR results. RESULTS: HPV DNA was detected in colorectal specimens of 60 patients with cancer (83.3%), but in none of the tissues from the non-malignant control group (p<0.001). Twenty-three cancer patients had HPV DNA detected in both the tumor and the matched normal tissue, 23 had HPV only in the tumor, and 14 had HPV only in the normal colorectal tissue. HPV16 was the viral type most frequently detected, being present in 41 out of 60 positive cases (68.3%). No correlation between the presence of the virus and specific prognostic predictors for the disease outcome was observed. CONCLUSION: HPV is present in the colon and rectum of most patients with colorectal adenocarcinoma, suggesting that this virus may be related to the pathogenesis of colorectal cancer.

Sentinel lymph node in carcinoma of the anal canal: a review.

AIMS: To review the studies investigating the efficacy of the sentinel lymph node (SLN) procedure in anal canal carcinoma and to evaluate its potential role in guiding a more selective approach for patients with the malignancy. METHODS: A literature search in the PubMed database was preformed using the key words "sentinel lymph node" and "anal cancer". All indexed original articles (except case reports) on the SLN procedure in cancer of the anal canal were analysed. RESULTS: There are five published series to date. Eighty-four patients were studied. Rates of SLN detection and removal ranged from 66 to 100% of patients investigated. Nodal metastases were found in 7.1 to 42% of cases. No serious complications were reported. CONCLUSIONS: The technique has proven to be safe and effective in sampling inguinal SLNs. The detection of occult metastases in clinically unsuspicious nodes represents an important improvement in the process of staging these patients, which has not been possible with any other method of diagnosis. Although SLN procedure is still in an early phase of investigation in this type of cancer, it emerges as an objective method to guide individual therapeutic decisions.

Massive zosteriform cutaneous metastasis from rectal carcinoma.

A 44-year-old man presented with a large and rapidly growing skin lesion approximately six months after resection of a rectal carcinoma. The lesion measured 40 cm in size, extended from the suprapubic area to the proximal half of the left groin, and showed a particular zosteriform aspect. Biopsy confirmed a metastatic skin adenocarcinoma. Cutaneous metastases from rectal cancer are very uncommon. Their gross appearance is not distinctive, although the skin tumors are usually solid, small (less than 5 cm) and painless nodules or papules. Early biopsies for suspicious skin lesions are needed in patients with a history of colorectal cancer.

[Magnifying colonoscopy in the diagnosis of colorectal carcinoma invading the submucosa in familial adenomatous polyposis]. / Colonoscopia com magnificação de imagem no diagnóstico de carcinoma colorretal invasivo da submucosa na polipose adenomatosa familiar.

The development of colonoscopy with image magnification has enable to study the colonic mucosa in detail and to do differential diagnosis between neoplastic and non-neoplastic lesions from the observation of pit patterns. The results are comparable to stereomicroscopy being possible to predict the histologic diagnosis. In a patient with familial adenomatous polyposis magnifying colonoscopy was performed and this method demonstrated a wide variation of benign polypoid lesions and the morphological features of early colorectal cancer. In this patient, the evaluation by image magnification, together with indigo carmin 0.4% chromoscopy, showed a wide variety of lesions in the colon and rectum: laterally spreading tumor in the cecum, with IIIL + IV pits, subpediculate polyp in the transverse colon with approximately 2.0 cm diameter and IV + V pits, flat elevated lesions IIIL type, and in the sigmoid colon IIa + IIc lesion with V type of Kudo's classification were observed. The evaluation of pit patterns of the lesions in the transverse and sigmoid colon has enable to do the endoscopic diagnosis of the lesion with submucosal invasion.