Biomedical subjects
Publications and source records attributed to S K Boolbol.
The current protocol for use of sentinel lymph node biopsy at Memorial Sloan-Kettering Cancer Center, NY, USA is described. The technique requires to be validated both by individual surgeons and institutions prior to use. Ongoing American multi-institutional trials to investigate the true role of sentinel lymph node biopsy are underway.
Sulindac, a non-steroidal anti-inflammatory drug (NSAID), is effective in treating intestinal adenomas in humans with Familial Adenomatous Polyposis (FAP) and in preventing intestinal tumors in the C57Bl/6J-Min+ (Min) mouse, an animal model of FAP. Sulindac is a prodrug metabolized by the liver and intestinal flora to a sulfone, which has no anti-inflammatory activity, and a sulfide, which is the active anti-inflammatory metabolite. In this study, we determined which of these metabolites is responsible for the anti-tumor effect of sulindac in Min mice. Min mice were treated with either sulindac sulfone or sulindac sulfide (0.5 +/- 0.1 mg/day). Min mice and homozygous C57Bl/6J-(+/+) normal litter-mates lacking the Apc mutation (+/+) were used as controls. At 110 days of age, all mice were euthanized and their intestinal tracts examined. Control Min mice had 33.2 +/- 6.6 tumors per mouse compared to 0.6 +/- 0.3 tumors for sulindac sulfide-treated Min mice (P < 0.001) and 21.9 +/- 4.5 tumors per mouse for sulindac sulfone-treated Min mice (P > 0.05). Decreased enterocyte apoptosis was observed in Min control mice and Min mice treated with sulindac sulfone. Sulindac sulfide restored to normal the level of apoptosis in the mucosa of Min animals and decreased levels of PGE2 in the small intestine of treated Min animals by 59% (P < 0.001). These data suggest that the anti-tumor effect of sulindac in Apc-deficient animals is mediated by the sulfide metabolite and correlates with suppression of tissue prostaglandin synthesis.
Apc-associated intestinal tumor formation appears to require functional loss of both Apc alleles. Apc has, therefore, been classified as a tumor suppressor gene. Loss of APC protein function results in increased intracellular beta-catenin, a molecule important to both cell-cell adhesion and regulation of cellular growth. In mice bearing a germ-line Apc mutation, we found that enterocyte beta-catenin expression was also increased in histologically normal intestinal mucosa. Enterocyte crypt-villus migration was decreased by 25%, and treatment of Min/+ animals with sulindac sulfide normalized both beta-catenin expression and enterocyte migration. Our data suggest that alterations in enterocyte migration occur in cells bearing a single mutant Apc allele, and that sulindac sulfide may normalize enterocyte growth in these cells.
Inducible cyclooxygenase (Cox-2), also known as prostaglandin H synthase 2 (PGH-2) is a key enzyme in the formation of prostaglandins and thromboxanes. Cox-2 is the product of an immediate-early gene that is expressed in response to growth factors, tumor promoters, or cytokines. Overexpression of Cox-2 is associated with both human colon cancers and suppression of apoptosis in cultured epithelia] cells, an activity that is reversed by the nonsteroidal anti-inflammatory drug, sulindac sulfide. To address the relationship between Cox-2, apoptosis, and tumor development in vivo, we studied C57BL/6J-Min/+(Min) mice, a strain containing a fully penetrant dominant mutation in the Apc gene, leading to the development of gastrointestinal adenomas by 110 days of age. Min mice were fed AIN-76A chow diet and given sulindac (0.5 +/- 0.1 mg/day) in drinking water. Control Min mice and homozygous C57BL/6J-+/+ normal littermates lacking the Apc mutation (+/+) were fed AIN-76A diet and given tap water to drink. At 110 days of age, all mice were sacrificed, and their intestinal tracts were examined. Control Min mice had 11.9 +/- 7.8 tumors per mouse compared to 0.1 +/- 0.1 tumors for sulindac-treated Min mice. As expected, +/+ littermates had no macroscopic tumors. Examination of histologically normal-appearing small bowel from Min animals revealed increased amounts of Cox-2 and prostaglandin E(2) compared to +/+ littermates. Using two different in situ techniques, terminal transferase-mediated dUTP nick end labeling and a direct immunoperoxidase method, Min animals also demonstrated a 27-47% decrease in enterocyte apoptosis compared to +/+ animals. Treatment with sulindac not only inhibited tumor formation but decreased small bowel Cox-2 and prostaglandin E(2) to baseline and restored normal levels of apoptosis. These data suggest that overexpression of Cox-2 is associated with tumorigenesis in the gastrointestinal epithelium, and that both are inhibited by sulindac administration.
BACKGROUND: The combined approach of radioactive tracer and blue-dye mapping of sentinel lymph nodes (SLN) has evolved into a safe and effective alternative to routine axillary node dissection in specific patient populations with breast carcinoma. The optimal route of injection for the isotope has not been clearly defined. To assess the intradermal route of isotope injection, we prospectively evaluated 100 patients with biopsy-proven invasive breast carcinoma with SLN biopsy followed by planned axillary node dissection. METHODS: All patients were given an intradermal injection of Tc-99m sulfur colloid and an intraparenchymal injection of blue dye. All patients underwent a complete axillary node dissection. Each sentinel node was serially sectioned and examined by immunohistochemistry. RESULTS: Sentinel nodes were successfully identified in 99% of cases. Forty-six patients had axillary metastases; of these, four had falsely negative sentinel nodes (false-negative rate, 9%). The false-negative rate was 0 of 24 (0%) for T1 tumors, 2 of 18 (11%) for T2 tumors, and 2 of 4 (50%) for T3 tumors. Three of four patients with false negatives had palpable, clinically suspicious axillary nodes found intraoperatively. If these cases are excluded, the accuracy of the procedure was 100% for T1 and T2 tumors. Of the 42 positive axillae identified by SLNB (true positives), 40 were localized using the intradermal injection of radioisotope; in 13 of these cases, this was the only method that identified the true-positive node. CONCLUSION: These data demonstrate that intradermal injection of radioactive tracer is an effective method of localizing the SLN in cases involving small breast cancers. Further investigation is warranted before this technique is adopted for use in larger breast cancers. Intraoperative examination and biopsy of any suspicious nonsentinel nodes are critical.