Expression of the monoclonal antibody-defined CAR-3 epitope on neoplastic and preneoplastic lesions of the colon mucosa

The Monoclonal Antibody-defined CAR-3 Antigen is a Serological Marker Associated with Pancreatic Carcinoma

The monoclonal antibody-defined CARS antigen is a new carcinoma associated marker which is expressed on a mucin-like molecule. Serum concentrations of CARS were assayed in 181 patients with carcinomas of different organs, 20 patients with non-carcinomatous malignancies, 123 patients with inflammatory diseases and 150 healthy controls. Serum levels of CARS were significantly increased in 51% of the patients with pancreatic carcinomas, in 60% of patients with biliary tract carcinomas and in about 15% of the patients with carcinomas of the digestive apparatus. Sera from patients with breast carcinomas were negative, as well as sera from patients with melanomas or sarcomas. CAR-3 values in samples from patients with chronic pancreatitis were constantly negative, as were samples from healthy donors. Significant concentrations of CAR-3 were detected in 20% of the sera from patients with acute pancreatitis and in 15% of the sera from patients with cirrhosis. Because of its high specificity for pancreatic carcinomas compared to chronic pancreatitis, CARS seems a promising marker for distinguishing between neoplastic and chronic inflammatory diseases of the pancreas, whose differential diagnosis is difficult.

New trends in guided nanotherapies for digestive cancers: A systematic review

Digestive tract tumors are among the most common and deadliest malignancies worldwide, mainly due to late diagnosis and lack of efficient therapeutics. Current treatments essentially rely on surgery associated with (neo)adjuvant chemotherapy agents. Despite an upfront response, conventional drugs often fail to eliminate highly aggressive clones endowed with chemoresistant properties, which are responsible for tumor recurrence and disease dissemination. Synthetic drugs also present severe adverse systemic effects, hampering the administration of biologically effective dosages. Nanoencapsulation of chemotherapeutic agents within biocompatible polymeric or lipid matrices holds great potential to improve the pharmacokinetics and efficacy of conventional chemotherapy while reducing systemic toxicity. Tagging nanoparticle surfaces with specific ligands for cancer cells, namely monoclonal antibodies or antibody fragments, has provided means to target more aggressive clones, further improving the selectivity and efficacy of nanodelivery vehicles. In fact, over the past twenty years, significant research has translated into a wide array of guided nanoparticles, providing the molecular background for a new generation of intelligent and more effective anti-cancer agents. Attempting to bring awareness among the medical community to emerging targeted nanopharmaceuticals and foster advances in the field, we have conducted a systematic review about this matter. Emphasis was set on ongoing preclinical and clinical trials for liver, colorectal, gastric and pancreatic cancers. To the best of our knowledge this is the first systematic and integrated overview on this field. Using a specific query, 433 abstracts were gathered and narrowed to 47 manuscripts when matched against inclusion/exclusion criteria. All studies showed that active targeting improves the effectiveness of the nanodrugs alone, while lowering its side effects. The main focus has been on hepatocarcinomas, mainly by exploring glycans as homing molecules. Other ligands such as peptides/small proteins and antibodies/antibody fragments, with affinity to either tumor vasculature or tumor cells, have also been widely and successfully applied to guide nanodrugs to gastrointestinal carcinomas. Conversely, few solutions have been presented for pancreatic tumors. To this date only three nanocomplexes have progressed beyond pre-clinical stages: i) PK2, a galactosamine-functionalized polymeric-DOX formulation for hepatocarcinomas; ii) MCC-465, an anti-(myosin heavy chain a) immunoliposome for advanced stage metastatic solid tumors; and iii) MBP-426, a transferrin-liposome-oxaliplatin conjugate, also for advanced stage tumors. Still, none has been approved for clinical use. However, based on the high amount of pre-clinical studies showing enthusiastic results, the number of clinical trials is expected to increase in the near future. A more profound understanding about the molecular nature of chemoresistant clones and cancer stem cell biology will also contribute to boost the field of guided nanopharmacology towards more effective solutions.

A prospective, blinded analysis of A-PROTEIN (recoverin or CAR protein) levels in pediatric patients with central nervous system tumors

BACKGROUND

Abnormal expression of A-PROTEIN has been identified in a number of tumors including carcinoma of the lung, breast, colon, prostate, and cervix. Brain tumors have been reported to express high plasma levels of A-PROTEIN, suggesting that it may be of significant diagnostic and prognostic value.

PROCEDURE

This prospective study evaluated the sensitivity and specificity of A-PROTEIN levels in pediatric brain tumor patients. Patients included those with newly diagnosed disease pre- and post-surgery, during treatment, during routine follow-up, and at recurrence or progression. A total of 154 A-PROTEIN levels from 54 patients were evaluated.

RESULTS

For patients without evidence of disease, 42% had normal A-PROTEIN levels, 35% were elevated, and 23% were equivocal. For patients with stable disease, 53% demonstrated normal A-PROTEIN levels, 19% were elevated, and 28% were equivocal. For patients with progressive disease, 53% had normal A-PROTEIN levels, 35% were elevated, and 12% were equivocal. The sensitivity was 35% and the specificity was 50%. A correlation of increased A-PROTEIN levels in patients with increased disease in glial tumors was also identified.

CONCLUSIONS

A-PROTEIN levels were not predictive of disease status in children with most brain tumors. However, in patients with glial tumors there was a correlation with increased disease and elevated A-PROTEIN levels. This could represent variability of A-PROTEIN during growth, development, or tumor cell origin and needs further evaluation.