The molecular basis of cancer and the development of targeted therapy

Synthesis and anticancer activity of some new pyrazolo[3,4-d]pyrimidin-4-one derivatives

3,6-Dimethyl-1-phenyl-1H-pyrazolo[3,4-d][1,3]oxazin-4-one (3) was prepared by hydrolysis of ethyl 5-amino-3-methyl-1-phenyl-1H-pyrazole-4-carboxylate (1) to afford the corresponding carboxylic acid 2, which was reacted with acetic anhydride to give 3. The pyrazolo[3,4-d][1,3]oxazin-4-one 3 was reacted with hydroxylamine hydrochloride, urea, thiourea, thiosemicarbazide, phenylhydrazine and aromatic amines to afford the corresponding pyrazolo[3,4-d]pyrimidin-4-ones 4, 5a,b, 6, 7, 8a-e, respectively. Condensation of pyrazoloxazine derivative 3 with 99% hydrazine hydrate afforded the 5-aminopyrazolo[3,4-d] pyrimidine derivative 9. Coupling of 9 with aromatic aldehydes yielded a series of 3,6-dimethyl-5-(4-substitutedbenzylideneamino)-1-phenyl-1,5-dihydropyrazolo[3,4-d]pyrimidin- 4-ones 10a-e. The new compounds were tested for their antitumor activity on the MCF-7 human breast adenocarcinoma cell line. Almost all the tested compounds revealed antitumor activity, especially 3,6-dimethyl-5-(4-nitrobenzylideneamino)-1-phenyl-1,5-dihydropyrazolo[3,4-d]pyrimidin-4-one (10e) which displayed the most potent inhibitory activity with a half maximal inhibitory concentration (IC₅₀) of 11 µM.

[(99m)Tc(CO)(3)]-radiolabeled bevacizumab: in vitro and in vivo evaluation in a melanoma model

INTRODUCTION

Vascular endothelial growth factor (VEGF) is one of the classic factors to tumor-induced angiogenesis in several tumor types, including melanoma. Bevacizumab, a monoclonal antibody against VEGF, could be used as an imaging tool in preclinical studies.

OBJECTIVE

To radiolabel bevacizumab with [(99m)Tc(CO)3(OH2)3](+) and evaluate it in vivo and in vitro for melanoma imaging properties.

METHODS

Bevacizumab was radiolabeled with [(99m)Tc(CO)3(OH2)3](+) ion in saline. The radiochemical stability of the labeled antibody was assessed. The biodistribution and scintigraphy imaging of the radiolabeled antibody were evaluated in normal C57BL/6J mice and in C57BL/6J mice bearing murine B16F1 melanoma tumors. Immunoreactivity of bevacizumab to murine tumors was determined from direct immunofluorescence and immunoblotting assays.

RESULTS

We demonstrate that (99m)Tc(CO)3-bevacizumab was stable. In vivo biodistribution studies revealed that tumor uptake of (99m)Tc(CO)3-bevacizumab was 2.64 and 2.51 %ID/g at 4 and 24 h postinjection. Scintigraphy image studies showed tumor selective uptake of (99m)Tc(CO)3-bevacizumab in the tumor-bearing mice. This affinity was confirmed by immunoassays performed on B16F10 tumor samples.

CONCLUSIONS

(99m)Tc(CO)3-bevacizumab could be used as an approach for tumor nuclear imaging in preclinical studies. This should be useful to provide insights into the angiogenic stimulus before and after chemotherapy, which might help improve current antitumor therapy.

Clinical significance of expression of Piwil2 in hepatocellular carcinoma

AIM: To investigate the mRNA and protein expression of Piwil2 in hepatocellular carcinoma (HCC), and to analyze their clinical significance.

METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect the expression of Piwil2 mRNA and protein in 70 surgical HCC specimens and matched tumor-adjacent non-cancerous specimens.

RESULTS: The relative expression level of Piwil2 mRNA was significantly higher in HCC than in tumor-adjacent non-cancerous tissue (0.91 ± 0.04 vs 0.32 ± 0.04, t = 37.240, P < 0.05). Piwil2 mRNA expression in HCC was correlated with tumor differentiation, intrahepatic invasion and metastasis. The protein expression of Piwil2 in HCC was also significantly higher than that in tumor-adjacent non-cancerous tissues. Piwil2 protein expression in HCC was correlated with intrahepatic invasion and metastasis. There was a significant correlation between the mRNA and protein expression of Piwil2 (χ² = 13.113, P < 0.01).

CONCLUSION: Piwil2 may be used as a novel biomarker for detection and therapy of HCC.

Radioactive iodine-refractory differentiated thyroid cancer: unmet needs and future directions

Approximately 90% of thyroid cancers are differentiated (DTCs) and have papillary, follicular or Hürthle cell morphology. Although treatment with surgery and radioactive iodine (I-131; RAI), as appropriate, is associated with significant cure rates and survival benefits, clonal disease progression with development of refractoriness to RAI poses a major therapeutic challenge in about 15% of patients. Traditional chemotherapeutic agents are relatively ineffective and are associated with significant toxicities. Molecular studies have demonstrated that the development and progression of DTC are associated with a series of consistent abnormalities in pathways such as MAPK/ERK and PI3/Akt, which govern cellular growth, proliferation, apoptosis and angiogenesis. Small molecular inhibitors that target these pathogenic pathways, without many of the impairments associated with cytotoxic chemotherapy, have demonstrated efficacy in a variety of malignancies, including renal cell carcinoma, hepatocellular carcinoma, non-small-cell lung cancer and chronic myelogenous leukemia. Several targeted therapeutic agents are in development for the treatment of RAI-refractory DTC. Sorafenib and lenvatinib are being studied in placebo-controlled Phase III trials based on encouraging efficacy results observed in single-arm Phase II studies.

Progress in molecularly targeted therapy for cholangiocarcinoma

Cholangiocarcinoma (CC) is an uncommon tumor that may arise anywhere from the biliary epithelium. Chinese CC patients account for more than 55% of CC cases in the world. Complete tumor resection has been recognized as the most effective therapy for CC. Unfortunately, only 10% of the patients are considered candidates for surgical resection. Long-term survival remains poor in these patients, and the5-year survival rate is about 5%. Median survival of patients with the tumor unresectable is only a few months. Although standard systemic chemotherapy approaches are emerging, the prognosis remains poor. Molecularly targeted therapies are a new treatment for advanced CC. The results of recent clinical trials of targeted therapies for CC appear promising. This article will review the molecular basis for targeted therapies for CC and evaluate recent clinical trials on targeted agents.

Relationship between baseline hepatic status and outcome, and effect of sorafenib on liver function: SHARP trial subanalyses

BACKGROUND & AIMS

Hepatic markers are utilized in many classification systems of patients with hepatocellular carcinoma and, by measuring organ damage and tumor stage, can influence treatment. Moreover, elevated serum concentrations of aminotransferases and alpha-fetoprotein are indicators of poor prognosis in patients with hepatocellular carcinoma. We examined the effects of sorafenib on hepatic markers by performing exploratory subset analyses of the Sorafenib HCC Assessment Randomized Protocol (SHARP) trial in patients categorized by baseline concentrations of alanine aminotransferase/aspartate aminotransferase, alpha-fetoprotein, and bilirubin; and by evaluating the effects of sorafenib on bilirubin concentrations during treatment.

METHODS

Patients (n=602) were grouped by baseline concentrations of alanine aminotransferase/aspartate aminotransferase (not significantly elevated, mildly elevated, or moderately elevated), alpha-fetoprotein (normal or elevated), and bilirubin (normal or elevated). Bilirubin was measured at baseline and on day 1 of each cycle.

RESULTS

Patients with elevated baseline concentrations of alanine aminotransferase/aspartate aminotransferase, alpha-fetoprotein, or bilirubin had shorter overall survival (OS) than those with normal baseline concentrations, irrespective of treatment group. No notable differences in safety profiles were observed between patients with normal vs. elevated alanine aminotransferase/aspartate aminotransferase, alpha-fetoprotein, or bilirubin. Median changes from baseline in bilirubin concentration at the last cycle of treatment were +0.17 and +0.19 mg/dl in the sorafenib and placebo groups, respectively.

CONCLUSIONS

These subset analyses suggest that sorafenib is safe and effective for hepatocellular carcinoma, irrespective of baseline alanine aminotransferase/aspartate aminotransferase, alpha-fetoprotein, or bilirubin concentration and that hepatic function remains stable over the course of sorafenib therapy.

The next step: innovative molecular targeted therapies for treatment of intracranial chordoma patients

BACKGROUND

Chordomas are rare, locally aggressive malignancies that often exhibit an insidious natural history and are difficult to eradicate. Surgery and radiotherapy are the treatment mainstays of chordoma, but the chance of local recurrence remains high. Patients who relapse or cannot undergo a complete en bloc resection generally have a poor prognosis. New agents for postoperative adjuvant treatment of chordomas are needed.

OBJECTIVE

To highlight potential clinical trials that could evolve from new insights into the molecular biology of chordoma.

METHODS

We performed a review of recent studies published in the literature that have begun to characterize the molecular features of chordoma, and with this knowledge, several targets for potential clinical therapies have been determined.

RESULTS

Several receptor tyrosine kinases and their downstream signaling cascades show dysregulation in chordoma and represent attractive targets for future therapeutic interventions. The pathways shown to be of particular importance in chordoma involve the platelet-derived growth factor receptor, epidermal growth factor receptor, hepatocyte growth factor receptor, and common downstream cascade of phosphoinositide 3-kinases, Akt, and mammalian target of rapamycin.

CONCLUSION

Recent findings characterizing the molecular biology of chordoma have illuminated multiple possible targets for future clinical trials. The availability of inhibitors against these aberrant pathways makes clinical trials with chordoma both feasible and immediately realizable. Additionally, we emphasize the rationale for combination therapy when implementing molecular therapy in chordoma and other cancers.

Subcutaneous Metastatic Adenocarcinoma: An Unusual Presentation of Colon Cancer - Case Report and Literature Review

Subcutaneous metastasis from a visceral malignancy is rare with an incidence of 5.3%. Skin involvement as the presenting sign of a silent internal malignancy is an even rarer event occurring in approximately 0.8%. We report a case of a patient who presented to her dermatologist complaining of rapidly developing subcutaneous nodules which subsequently proved to be metastatic colon cancer, and we provide a review of the literature.

Targeted Therapy Database (TTD): a model to match patient's molecular profile with current knowledge on cancer biology

Background

The efficacy of current anticancer treatments is far from satisfactory and many patients still die of their disease. A general agreement exists on the urgency of developing molecularly targeted therapies, although their implementation in the clinical setting is in its infancy. In fact, despite the wealth of preclinical studies addressing these issues, the difficulty of testing each targeted therapy hypothesis in the clinical arena represents an intrinsic obstacle. As a consequence, we are witnessing a paradoxical situation where most hypotheses about the molecular and cellular biology of cancer remain clinically untested and therefore do not translate into a therapeutic benefit for patients.

Objective

To present a computational method aimed to comprehensively exploit the scientific knowledge in order to foster the development of personalized cancer treatment by matching the patient's molecular profile with the available evidence on targeted therapy.

Methods

To this aim we focused on melanoma, an increasingly diagnosed malignancy for which the need for novel therapeutic approaches is paradigmatic since no effective treatment is available in the advanced setting. Relevant data were manually extracted from peer-reviewed full-text original articles describing any type of anti-melanoma targeted therapy tested in any type of experimental or clinical model. To this purpose, Medline, Embase, Cancerlit and the Cochrane databases were searched.

Results and Conclusions

We created a manually annotated database (Targeted Therapy Database, TTD) where the relevant data are gathered in a formal representation that can be computationally analyzed. Dedicated algorithms were set up for the identification of the prevalent therapeutic hypotheses based on the available evidence and for ranking treatments based on the molecular profile of individual patients. In this essay we describe the principles and computational algorithms of an original method developed to fully exploit the available knowledge on cancer biology with the ultimate goal of fruitfully driving both preclinical and clinical research on anticancer targeted therapy. In the light of its theoretical nature, the prediction performance of this model must be validated before it can be implemented in the clinical setting.