Laparoscopic resection is inappropriate in patients with known or suspected adrenocortical carcinoma.

BACKGROUND: Complete surgical resection is the mainstay of treatment for patients with adrenocortical cancer (ACC). Use of laparoscopy has been questioned in patients with ACC. This study compares the outcomes of patients undergoing laparoscopic versus open resection (OR) for ACC. METHODS: A retrospective review (2003-2008) of patients with ACC was performed. Data were collected for demographics, operative and pathologic data, adjuvant therapy, and outcome. Chi-square analysis was performed. RESULTS: Eighty-eight patients (66% women; median age, 47 (range, 18-81) years) were identified. Seventeen patients underwent laparoscopic adrenalectomy (LA). Median tumor size of those who underwent LA was 7.0 (range, 4-14) cm versus 12.3 (range, 5-27) cm for OR. Recurrent disease in the laparoscopic group occurred in 63% versus 65% in the open group. Mean time to first recurrence for those who underwent LA was 9.6 months (+/-14) versus 19.2 months (+/-37.5) in the open group (p < 0.005). Fifty percent of patients who underwent LA had positive margins or notation of intraoperative tumor spill versus 18% of those who underwent OR (p = 0.01). Local recurrence occurred in 25% of the laparoscopic group versus 20% in the open group (p = 0.23). Mean follow-up was 36.5 months (+/-43.6). CONCLUSIONS: ACC continues to be a deadly disease, and little to no progress has been made from a treatment standpoint in the past 20 years. Careful and complete surgical resection is of the utmost importance. Although feasible in many cases and tempting, laparoscopic resection should not be attempted in patients with tumors suspicious for or known to be adrenocortical carcinoma.

Respiratory viral infection in lower airways of asymptomatic children.

AIM: The aim of this study was to determine if asthmatic children have viruses more commonly detected in lower airways during asymptomatic periods than normal children. METHODS: Fifty-five asymptomatic children attending elective surgical procedures (14 with stable asthma, 41 normal controls) underwent non-bronchoscopic bronchoalveolar lavage. Differential cell count and PCR for 13 common viruses were performed. RESULTS: Nineteen (35%) children were positive for at least one virus, with adenovirus being most common. No differences in the proportion of viruses detected were seen between asthmatic and normal 'control' children. Viruses other than adenovirus were associated with higher neutrophil counts, suggesting that they caused an inflammatory response in both asthmatics and controls (median BAL neutrophil count, 6.9% for virus detected vs. 1.5% for virus not detected, p = 0.03). CONCLUSIONS: Over one-third of asymptomatic children have a detectable virus (most commonly adenovirus) in the lower airway; however, this was not more common in asthmatics. Viruses other than adenovirus were associated with elevated neutrophils suggesting that viral infection can be present during relatively asymptomatic periods in asthmatic children.

Level VI lymph node dissection for papillary thyroid cancer.

Papillary thyroid cancer (PTC) is the most common endocrine malignancy and commonly metastasizes to regional lymph nodes. Surgical treatment of cervical lymph nodes in PTC remains controversial. It has traditionally been accepted that regional lymph node metastases in PTC may increase local recurrence rates but do not ultimately affect survival. This conventional wisdom has been challenged by recent reports indicating that regional lymph node metastases do increase mortality. Thus, there has been renewed interest in operative control of nodal disease for PTC. A systematic review of central lymph node dissection (CLND) in the recent literature using evidence-based criteria permitted formation of the following five recommendations: 1) limited data suggest benefit with the addition of prophylactic CLND to thyroidectomy (grade C); 2) systematic compartment-oriented CLND may decrease recurrence of PTC and improve disease-specific survival (no grade); 3) the addition of CLND to total thyroidectomy can significantly reduce levels of serum thyroglobulin and increase rates of athyroglobulinemia (no grade); 4) there may be a higher rate of permanent hypoparathyroidism and unintentional permanent nerve injury when CLND is performed with total thyroidectomy than for total thyroidectomy alone (grade C); 5) reoperation in the central neck compartment for recurrent PTC may increase the risk of hypoparathyroidism and unintentional nerve injury when compared to total thyroidectomy with or without CLND, supporting a more aggressive initial operation by experienced endocrine surgeons (grade C). Taken together, these recommendations support the application of routine CLND at the initial operation for papillary thyroid cancer in expert hands.

Management of patients with adrenal cancer: recommendations of an international consensus conference.

Adrenocortical carcinomas are rare, highly malignant tumors that account for only 0.2% of deaths due to cancer. Given the limited number of patients seen in most medical centers with this diagnosis, series usually reported are small and clinical trials not randomized or blinded. In an attempt to answer important questions concerning the management of patients with adrenal cancer, a consensus conference was organized and held at the University of Michigan in Ann Arbor, MI, 11-13 September 2003, with the participation of an international group of physicians who had reported on the largest series of patients with this disease and who had recognized basic and clinical research expertise in adrenal cortical cancer. Totally 43 questions were addressed by the presenters and recommendations discussed in plenary and breakout sessions. Evidence for the recommendations of this conference was at the 2-4+ level and based on available literature and participants' experience. In addition to setting up guidelines in specific areas of the diagnosis and treatment of adrenal cancer, the conference recommended and initiated the planning of an international prospective trial for treatment of patients with adrenal cancer in stages III and IV. In terms of new therapies, first trials of dendritic cell therapy in human subjects with adrenal cancer have been started, but it is too early to comment on efficacy. Different strategies of immunotherapy, including DNA vaccination are currently being tried in animal models. There are no clinical gene therapy trials for human adrenal cortical cancer. The adrenals are a preferred target for adenovirus and the results of gene therapy in preclinical studies are promising. In addition, there is evidence that histone deacetylase inhibitors can further enhance the rate of adenoviral infectivity in human adrenal cancer cells. Testing of retroviral vectors, non-viral vectors, small interfering RNA technology, and combined approaches could be performed in various laboratories. Anti-angiogenic substances have only been applied in preclinical studies. The use of these and other agents in the treatment of adrenal cancer should be hypothesis-driven and based on a thorough analysis of tumor biology.

Children with stable asthma have reduced airway matrix metalloproteinase-9 and matrix metalloproteinase-9/tissue inhibitor of metalloproteinase-1 ratio.

BACKGROUND: Childhood asthma is characterized by inflammation of the airways. Structural changes of the airway wall may also be seen in some children early in the course of the disease. Matrix metalloproteinases (MMPs) are key mediators in the metabolism of the extracellular matrix (ECM). OBJECTIVE: To investigate the balance of MMP-8, MMP-9 and tissue inhibitor of metalloproteinases (TIMP)-1 in the airways of children with asthma. METHODS: One hundred and twenty-four children undergoing elective surgical procedures also underwent non-bronchoscopic bronchoalveolar lavage (BAL). MMP-8, MMP-9 and TIMP-1 were measured by ELISA. RESULTS: There was a significant reduction in MMP-9 in atopic asthmatic children (n=31) compared with normal children (n=30) [median difference: 0.57 ng/mL (95% confidence interval: 0.18-1.1 ng/mL)]. The ratio of MMP-9 to TIMP-1 was also reduced in asthmatic children. Levels of all three proteins were significantly correlated to each other and to the relative proportions of particular inflammatory cells in BAL fluid (BALF). Both MMP-8 and MMP-9 were moderately strongly correlated to the percentage neutrophil count (r=0.40 and 0.47, respectively, P<0.001). CONCLUSIONS: An imbalance of MMPs and their inhibitors occurs in children with well-controlled asthma, which may indicate early derangement of the metabolism of the ECM.

Non-bronchoscopic sampling and culture of bronchial epithelial cells in children.

BACKGROUND: The bronchial epithelium is likely to play a vital role in airway diseases in children, such as asthma and viral-associated wheeze. In adults, studies with primary bronchial epithelial cells cultured from samples obtained by fibre-optic bronchoscopy have provided key insights into the role of the epithelial cell. However, it is difficult to justify bronchoscopy in children to obtain epithelial cells for research purposes. OBJECTIVE: To examine the possibility of retrieving and culturing viable epithelial cells using a blind non-bronchoscopic method from children undergoing elective surgery. METHODS: Subjects were children undergoing elective surgery under general anaesthesia. Following intubation, non-bronchoscopic bronchoalveolar lavage and non-bronchoscopic bronchial brushing were performed. A sheathed bronchial cytology brush was advanced through the endotracheal tube, wedged and then withdrawn 2-3 cm before gentle sampling was used to collect bronchial epithelial cells. Initial samples were used to characterize the number, type and viability of epithelial cells recovered compared to a control group of adults undergoing standard bronchoscopic sampling. Subsequent samples were used to establish primary bronchial epithelial cell cultures in children both with and without wheezing illness. RESULTS: A total of 63 children underwent bronchial brushing [38 male; median age 7.1 years (1.0-14.2 years]. Initial samples (n=30) showed recovery of viable epithelial cells comparable to that from a single brush obtained via a bronchoscope in an adult control group (n=11). In 27 (82%) of the subsequent 33 samples obtained non-bronchoscopically from children, primary bronchial epithelial cell cultures were successfully established. There were no adverse effects attributable to sampling. CONCLUSION: We have shown that non-bronchoscopic bronchial brushing is a safe and effective technique for recovering viable bronchial epithelial cells that consistently yield primary cultures. This method will facilitate examination of the role of the epithelium in paediatric disease.

Role of endoscopic ultrasonography in screening and treatment of pancreatic endocrine tumours in asymptomatic patients with multiple endocrine neoplasia type 1.

BACKGROUND: Patients with multiple endocrine neoplasia (MEN) type 1 risk premature death from pancreatic endocrine tumours (PETs). Endoscopic ultrasonography (EUS) is the most sensitive imaging modality for small PETs. A screening and therapeutic approach for asymptomatic patients is delineated in which EUS plays a pivotal role. METHODS: This was a retrospective study of 15 patients with MEN-1 but with no symptoms of a PET. All patients underwent serum hormone measurement, including gastrin, and EUS. The findings were used to facilitate operative treatment. RESULTS: Six of 15 patients had a normal basal gastrin level and nine had a raised level. EUS demonstrated PETs in 14 patients and identified multiple lesions in 12. There was no predictive relationship between age or gastrin level and the number or size of PETs discovered. Thirteen patients have undergone enucleation or resection of PETs and two remain under observation. Nine of the 13 patients underwent transduodenal exploration to excise gastrinoma(s). One patient had lymph node metastases found at operation. There was no death. Self-limiting pancreatic fistula in five patients and biliary fistula in one. CONCLUSION: Early and aggressive screening using EUS identifies PETs in asymptomatic patients with MEN-1. Detection of tumours at an early stage, before the development of symptoms, lymph node metastases or liver metastases, may facilitate prompt surgical intervention and improve prognosis.

Multiple endocrine neoplasia type 1: duodenopancreatic tumours.

The pancreaticoduodenal disease in Multiple endocrine neoplasia type 1 (MEN1) is the most frequent cause of death due to the syndrome, and the most controversial with regard to its management. This article discusses the current data and recommendations with respect to disease screening, functional tumour diagnosis, natural history, preoperative imaging, operative strategy and follow-up.

Risk of malignancy in thyroid incidentalomas identified by fluorodeoxyglucose-positron emission tomography.

BACKGROUND: Thyroid tumors often exhibit increased metabolic activity, as evidenced by enhanced glucose uptake on positron emission tomography (PET) with use of (18)F-fluorodeoxyglucose (FDG). The incidence of new thyroid lesions found on routine FDG-PET has not been previously reported. METHODS: A retrospective review of all patients who underwent FDG-PET imaging at our institution from June 1, 1996, through March 15, 2001, identified patients with a newly diagnosed thyroid lesion. Thyroid incidentaloma was defined as a thyroid lesion seen initially on FDG-PET in a patient without a history of thyroid disease. Available follow-up data were documented. RESULTS: One hundred and two of 4525 FDG-PET examinations (2.3%) demonstrated thyroid incidentalomas. Eighty-seven of 102 patients had no thyroid histology because of other malignancies. Fifteen patients had thyroid biopsy: 7 (47%) with thyroid cancer, 6 (40%) with nodular hyperplasia, 1 with thyroiditis, and 1 with atypical cells of indeterminate origin. The average standardized uptake values were higher for malignant compared with benign lesions. CONCLUSIONS: Thyroid incidentaloma identified by FDG-PET occurred with a frequency of 2.3%. Of the thyroid incidentalomas that underwent biopsy, 47% were found to be malignant. Given the risk of malignancy, patients with new thyroid lesions on PET scan should have a tissue diagnosis if it will influence outcome and management. Standardized uptake values may be helpful in predicting benign versus malignant histology.

Outcomes analysis in patients undergoing laparoscopic adrenalectomy for hormonally active adrenal tumors.

BACKGROUND: Laparoscopic adrenalectomy (LA) has become the preferred method of removal of most adrenal neoplasms, but few studies have evaluated the functional outcomes of this approach. The purpose of this study was to analyze our operative results and the clinical and biochemical responses to LA in patients with various hormonally active adrenal tumors. METHODS: From 1993 through November 2000, 72 patients with functional adrenal tumors underwent attempted LA. Data were obtained retrospectively by review of medical records, during routine follow-up, and by patient questionnaire. RESULTS: Indications for adrenalectomy were pheochromocytoma (n = 35), aldosteronoma (n = 29), cortisol-producing adenoma (n = 5), and adrenocorticotropic hormone-dependent Cushing's syndrome (n = 3). LA was completed in 70 of 72 patients, with 2 conversions (3%) to open adrenalectomy. Mean operative time for unilateral LA was 176 +/- 60 minutes, and postoperative length of hospital stay averaged 3.0 +/- 1.7 days. Complications, most of which were minor, occurred in 19% of patients; there were no serious complications or perioperative deaths. Two patients were unavailable for follow-up. At a mean follow-up interval of 37.6 months after LA (range, 2-90 months), resolution of clinical and biochemical signs of adrenal hyperfunction was accomplished in 34 of 34 patients with pheochromocytomas, 25 of 26 patients with aldosteronomas, 5 of 5 patients with cortisol-producing adenomas, and 3 of 3 patients with andrenocorticotropic hormone-dependent Cushing's syndrome. Two patients with multiple endocrine neoplasia (MEN) type 2 had contralateral pheochromocytomas removed 4 and 5 years after the initial surgery. Persistent hypertension necessitating medication was present in 72% of patients with aldosteronomas, although 92% of these patients had improved blood pressure control after LA. Recurrent hypokalemia developed in 1 patient (4%) with a cortical nodule in the contralateral adrenal. No local or distant tumor recurrences have occurred. CONCLUSIONS: LA results in an excellent clinical outcome in patients with various functional endocrine tumors. LA is associated with few major complications, and clinical and biochemical cure rates are comparable with those of open adrenalectomy during long-term follow-up.

Interferon regulatory factor expression in human breast cancer.

OBJECTIVE: To investigate the expression of interferon regulatory factors 1 and 2 (IRF-1 and IRF-2) in human breast cancer. SUMMARY BACKGROUND DATA: Interferon regulatory factors 1 and 2 are transcription factors in the interferon gamma signal transduction pathway. IRF-1 acts as the effector arm of the interferon gamma response; IRF-2 binds to the same DNA consensus sequence and opposes IRF-1 activity. Previous work in the authors' laboratory has shown the tumor suppressor activity of IRF-1 expression and the oncogenic effect of IRF-2 in human and murine tumor models, including human breast cancer cell lines. The authors' hypothesis is that this pathway is involved in human tumor development, and alterations in the expression of IRF-1 and IRF-2 may occur in breast cancer tissue compared with normal breast tissue, and between more and less differentiated breast cancers. METHODS: Formalin-fixed paraffin-embedded human archival tissue specimens were obtained from 33 patients with pure ductal carcinoma in situ (DCIS) and 49 women with invasive ductal cancer. Adjacent areas of normal breast tissue were assayed in 31 women. These specimens were stained with polyclonal IRF-1 and IRF-2 antibodies using an avidin-biotin-peroxidase complex technique after epitope retrieval. RESULTS: Most normal breast tissue showed expression of IRF-1 and no expression of IRF-2 by immunohistochemistry. High-grade DCIS or node-positive invasive ductal cancers were less likely to express the tumor suppressor IRF-1 than normal tissue. More strikingly, high-grade DCIS and invasive ductal cancers were much more likely to express the oncogenic IRF-2 protein than was normal tissue. CONCLUSIONS: Expression of IRF-1 and IRF-2 is altered in human breast cancer compared with normal adjacent tissue. The loss of IRF-1 expression is consistent with tumor suppressor loss and the development of IRF-2 expression with oncogenic activation. These data support the hypothesis that this pathway is involved in human breast oncogenesis, which warrants further investigation regarding prognostic and therapeutic implications.

Pancreatic endocrine tumors.

Pancreatic endocrine tumors are rare but have long held a fascination for clinicians because of the physiologic derangements that they can cause, and the dramatic corrections that can be achieved by appropriate management. In the year reviewed in this article, the literature again demonstrated the ongoing interest and research in this area. In particular, the areas of gastrinoma, insulinoma, and multiple endocrine neoplasia type 1 have received careful attention.

Minimal incision parathyroidectomy: cure, cosmesis, and cost.

The goals of operative treatment of primary hyperparathyroidism are (1) cure; (2) minimal invasion; and (3) cost-effectiveness. The optimal strategy is controversial. Retrospective review of was undertaken 66 previously unoperated patients having minimal-incision, full-neck exploration by one surgeon over 29 months. A group of 51 women and 15 men had open full neck exploration under general anesthesia through a small (25-40 mm) incision using specifically selected instruments; patients remained hospitalized overnight. Preoperative sestamibi scans were obtained before referral for 17 patients: 11 had localized disease, and 6 did not (65% sensitivity). Four parathyroid glands were identified in 98% of patients; intraoperative frozen section was used selectively on a median of one gland per patient. About 76% of patients had single-gland disease, 6% had two-gland disease, and 18% had four-gland hyperplasia. One patient had four normal cervical parathyroid glands and an aortopulmonary window parathyroid adenoma resected at thoracotomy 1 week later; preoperative sestamibi scans failed to localize his disease. There were no nerve injuries and a 98% cure rate after initial cervical exploration. Excluding the cost of the sestamibi scans, there was no difference between those who had preoperative localization and those who did not; 60% of hospital costs were operating room time-related. Minimal-incision parathyroidectomy is effective for curing hyperparathyroidism and has excellent cosmetic results with negligible scar. Preoperative sestamibi scanning had no impact on cure or treatment costs. Strategies to improve cost-effectiveness must address the substantial costs of anesthesia and operating room services.

Duodenopancreatic resections in patients with multiple endocrine neoplasia type 1.

OBJECTIVE: To review the authors' 7-year experience with a surgical approach for pancreatic and duodenal neuroendocrine tumors (NETs) in patients with multiple endocrine neoplasia type 1 (MEN 1) designed to remove all gross tumor with limited complications, preserving pancreatic function. SUMMARY BACKGROUND DATA: MEN 1 is an autosomal dominant familial neoplasia syndrome characterized by the development of NETs of the duodenum and pancreas. Some tumors are clinically insignificant or follow a benign course, although a subset pursues a malignant, lethal natural history; the risk of surgical management must be appropriate to the disease course. METHODS: The clinical, biochemical, genetic, and pathologic data were retrospectively reviewed for 21 consecutive MEN 1 patients undergoing pancreatic resection for NETs between 1993 and 1999 at one institution. Age at operation, presenting symptoms, results of preoperative and intraoperative localization studies, major and minor complications, and pathology, including metastases, were analyzed. RESULTS: The surgical approach was selected based on the location and size of the tumors. Five patients required pancreaticoduodenectomy, 11 patients underwent non-Whipple pancreatic resections, and 5 underwent simple enucleation of benign NETs. The incidence of regional lymph node metastases was 33%. CONCLUSIONS: Major pancreatic procedures can be performed safely in most patients with MEN 1 and NETs. Because NETs are the most common MEN 1-related cause of death in the authors' kindreds, an aggressive surgical approach, including early intervention before malignant spread and major pancreatic resection where indicated, appears justified.

Papillary thyroid cancer.

Papillary thyroid cancer is the most common neoplasm of the thyroid gland. Surgical resection is the cornerstone of therapy. There is controversy regarding the extent of resection, ranging from thyroid lobectomy plus isthmusectomy to total thyroidectomy, but in experienced hands total thyroidectomy has many significant advantages over a lesser operation. Nonoperative therapy has no role as primary therapy for papillary thyroid cancer, but can be used in conjunction with surgery to improve outcome. Radioiodine in patients who have received total thyroidectomy can be used to identify residual occult tumor, recurrence, and metastasis, and can also be used to ablate the neoplasm, resulting in a substantial cure rate. Thyroid hormone is needed as replacement after total thyroidectomy, but can also be given as thyroid-stimulating hormone suppression, which may have an adjunctive benefit after resection.

Multiple endocrine neoplasia type 1: clinical and genetic features.

Multiple endocrine neoplasia type 1 has intrigued clinicians since its description because of its rarity and complex presentation of tumours in disparate endocrine organs. Its unpredictable course has made the development of strategies for clinical management difficult. The frequently indolent course in some family members, punctuated by lethal, aggressively malignant disease in others, has been frustrating as we strive to develop low-morbidity schemes for the prevention of the lethal manifestations of the syndrome. The recent description of the genetic abnormality responsible for the disease in many, if not all, families, will be of great assistance, even if it only allows the cessation of diagnostic testing for kindred members who are found to not carry the genetic abnormality. In fact, there is great promise in this discovery, as it may shed light on significant aspects of neuroendocrine oncogenesis. In spite of this, the clinical management strategies for these families will require further focused attention, in order to develop rational, prospective studies to answer the many questions that remain.

Preservation of the recurrent laryngeal nerves in thyroid and parathyroid reoperations.

BACKGROUND: The recurrent laryngeal nerve (RLN) is vulnerable to injury in thyroid and parathyroid reoperations because of the presence of scar tissue and displacement of the nerve from its normal position. METHODS: Since 1993, we have performed 132 reoperations for recurrence of thyroid or parathyroid carcinoma (102 cases), persistent hyperparathyroidism (21 cases), and recurrent goiter (9 cases). One or both RLNs were identified in all cases (208 nerves). Exposure of the nerve was accomplished by a lateral approach (159 nerves), a low anterior approach (41 nerves), or the identification of the nerve between the larynx and the upper pole of the thyroid, in parathyroid reoperations (8 nerves). Dissection was then done while the nerve was kept in view at all times. RESULTS: Preoperatively, unilateral vocal cord paralysis was noted in 6 patients. Resection of a functioning RLN encased with a tumor was intentionally carried out in 5 patients. The RLNs were identified and preserved in all other cases. Among these 121 patients, transient hoarseness lasting up to a month occurred in 12 patients. CONCLUSIONS: Careful identification and exposure of the RLN through a previously undissected area can be done safely in thyroid and parathyroid reoperations and resulted in no permanent recurrent nerve injuries in our experience.

Interferon regulatory factor-1 and -2 expression in human melanoma specimens.

BACKGROUND: Interferon regulatory factor (IRF)-1 and IRF-2 are nuclear transcription factors that respond to interferon-gamma. IRF-1 acts as the effector arm of the interferon-gamma response in tumor cells, whereas IRF-2 binds to the same DNA consensus sequence and opposes IRF-1 activity. This effect is intact in human and murine tumor models, including melanomas; previous work in our laboratory demonstrated the tumor-suppressing activity of IRF-1 expression in in vivo models and the opposing effect of IRF-2. The expression of IRF-1 and -2 in human solid tumors had not been previously investigated. METHODS: Formalin-fixed, paraffin-embedded, archival tissue specimens from 38 human melanomas were obtained and stained with polyclonal anti-IRF-1 and anti-IRF-2 antibodies, using an avidin-biotin-peroxidase complex technique with epitope retrieval. RESULTS: Twenty-nine specimens showed granular cytoplasmic staining with the anti-IRF-1 or anti-IRF-2 antibodies. IRF-1 staining was correlated with less advanced disease. Superficial spreading and in situ lesions exhibited more frequent IRF-1 staining, compared with nodular or metastatic disease. Only more advanced lesions showed neither IRF-1 nor IRF-2 staining. CONCLUSIONS: Immunohistochemical staining of archival tissue identified IRF-1 and -2 in human melanomas; this had not been previously demonstrated. IRF-1 staining was correlated with the morphologic characteristics of less advanced disease. Tumor-suppressing effects of IRF-1 may account for the less aggressive biologic features of IRF-1-expressing melanomas, as we would predict from the experimental data.

Enhancing in vivo tumorigenicity of B16 melanoma by overexpressing interferon regulatory factor-2: resistance to endogenous IFN-gamma.

We investigated the role of interferon (IFN) regulatory factor-2 (IRF-2) as an oncoprotein in vivo, opposing endogenous IFN-gamma suppression of tumor growth. Using syngeneic IFN-gamma knockout mice, we show that endogenous IFN-gamma slows growth of the mouse melanoma cell line B16-F10 in immunocompetent mice, suggesting that tumor cell resistance to IFN-gamma may lead to greater tumorigenicity. IRF-2 is a nuclear transcription factor induced by IFN-gamma that represses numerous IFN-inducible genes, including genes that regulate cell growth, in opposition to the transcriptional activator IRF-1. B16-F10 has a marked growth inhibitory response to IFN-gamma in vitro and has very little IRF-2 induction compared with other murine tumor cell lines. We engineered B16-F10 cells to stably overexpress murine IRF-2. In vitro, these transfected cells showed a marked resistance to the growth-inhibitory effect of IFN-gamma. In normal mice the IRF-2-transfected cells grew much faster than control tumors. In syngeneic IFN-gamma knockout mice, control cells grew at a rate similar to that of IRF-2-transfected cells, implicating resistance to endogenous IFN-gamma as playing the major role in enhanced growth of IRF-2-transfected tumors in intact mice. These experiments demonstrate that (1) IRF-2 enhances B16 melanoma growth and increases resistance to IFN-gamma in vitro, and (2) IRF-2 opposes the growth suppression mediated by endogenous IFN-gamma in vivo.

Recognition of breast cancer-associated peptides by tumor-reactive, HLA-class I restricted allogeneic cytotoxic T lymphocytes.

Strategies to identify tumor-associated antigens rely on the paradigm that tumor-associated peptides presented in the context of HLA-class I are recognized by the cellular immune system. Approaches to isolate tumor-specific cytotoxic T lymphocytes (CTL) from tumor-infiltrating lymphocytes are difficult because long-term growth of the CTL requires autologous tumor cells and lymphocytes (PBL) as feeder cells. In this study, a CTL line (BL.HBL-100 CTL) was generated from PBL from a normal healthy donor by stimulating with irradiated, HLA-class I partially matched breast cancer cell line HBL-100. Activated T lymphocytes generated expressed TCR alpha/beta+ with a predominant CD8+ population after 12 stimulations (98.54% CD8+ vs. 0.18% CD4+). These CTL lysed HLA-A1+, but not HLA-A1-, breast cancer cell lines. Moreover, HLA-A1+, non breast cancer cell lines were not recognized. The lytic activity of BL.HBL-100 CTL against HLA-A1+ breast cancer cell lines was blocked by monoclonal antibodies (MAbs) to HLA-class I and CD8, but not by anti-HLA-class II and CD4. Recognition of HLA-A1+ breast cancer cells by the CTL was dependent on peptides associated with HLA-class I since the lysis was inhibited by acid elution of HLA bound peptides. HBL-100 tumors were grown in severe combined immunodeficient (SCID) mice. Immunohistochemical staining of the HBL-100 tissue harvested from SCID mice demonstrated human breast cancer cells. HLA-class I molecules were affinity purified from the HBL-100 harvested from the SCID mice; class I bound peptides were eluted and separated by RP-HPLC. Pooled HPLC peptide fractions were tested for reconstituting antigenic epitopes recognized by the BL.HBL-100 CTL and found to reside within fraction 40. Our results show that a tumor reactive, HLA-class I restricted CTL was produced by stimulating normal PBL against an HLA-class I matched breast cancer cell line. We also provide evidence for a breast cancer-associated, HLA-class I bound peptide antigen(s) that reconstitutes the antigenic epitope(s) recognized by these CTL.