Investigation into the Role of Tumor-Associated Macrophages in the Antitumor Activity of Doxil

Purpose. Our recent studies show specific localization of long-circulating liposomes (LCL) within the endosomal/lysosomal compartment of tumor-associated macrophages (TAM). Based on this finding, the present study aims to investigate whether clinically applied LCL formulations such as Doxil (LCLencapsulated doxorubicin), have alternative mechanisms of action additionally to direct drug-mediated cytotoxicity towards tumor cells. Methods. The antitumor activity of Doxil was evaluated in B16.F10 melanoma-bearing mice, in the presence and in the absence of TAM. To suppress TAM functions, liposomal clodronate (Lip-CLOD) was injected 24 h before the actual treatment. The effect of Doxil on the levels of angiogenic factors was determined using an angiogenic protein array. As positive control, the same experiments were conducted with LCL-encapsulated prednisolone phosphate (LCL-PLP), a tumor-targeted formulation with known strong anti-angiogenic/anti-inflammatory effects on TAM. Results. Our results show that the antitumor efficacy of Doxil was only partially attributed to the inhibition of TAM-mediated angiogenesis whereas LCL-PLP inhibited tumor growth through strong suppressive effects on pro-angiogenic functions of TAM. As described previously, the main mechanism of Doxil might be a cytotoxic effect on tumor cells. Conclusions. Our findings suggest that the antitumor activity of Doxil does not depend mainly on the presence of functional TAM in tumors

A prospective controlled study of sexual function and sexually related personal distress up to 12 months after premenopausal risk-reducing bilateral salpingo-oophorectomy

OBJECTIVE: Premenopausal risk-reducing bilateral salpingo-oophorectomy (RRBSO) may impair sexual function, but the nature and degree of impairment and impact of estrogen therapy on sexual function and sexually related personal distress after RRBSO are uncertain. METHODS: Prospective observational study of 73 premenopausal women at elevated risk of ovarian cancer planning RRBSO and 68 premenopausal controls at population risk of ovarian cancer. Participants completed the Female Sexual Function Index and the Female Sexual Distress Scale-Revised. Change from baseline in sexual function following RRBSO was compared with controls at 12 months according to estrogen therapy use. RESULTS: Baseline sexual function domains did not differ between controls and those who underwent RRBSO and subsequently initiated (56.2%) or did not initiate (43.8%) estrogen therapy. At 12 months, sexual desire and satisfaction were unchanged in the RRBSO group compared with controls. After RRBSO, nonestrogen therapy users demonstrated significant impairment in sexual arousal (β-coefficient (95% confidence interval) -2.53 (-4.86 to -0.19), P < 0.03), lubrication (-3.40 (-5.84 to -0.96), P < 0.006), orgasm (-1.64 (-3.23 to -0.06), P < 0.04), and pain (-2.70 (-4.59 to 0.82), P < 0.005) compared with controls. Although sexually related personal distress may have been more likely after RRBSO, irrespective of estrogen therapy use, there was insufficient data to formally test this effect. CONCLUSIONS: The findings suggest premenopausal RRBSO adversely affects several aspects of sexual function which may be mitigated by the use of estrogen therapy. Further research is needed to understand the effects of RRBSO on sexual function and sexually related personal distress, and the potential for estrogen therapy to mitigate against any adverse effects

DNA-based therapeutics and DNA delivery systems: A comprehensive review

The past several years have witnessed the evolution of gene medicine from an experimental technology into a viable strategy for developing therapeutics for a wide range of human disorders. Numerous prototype DNA-based biopharmaceuticals can now control disease progression by induction and/or inhibition of genes. These potent therapeutics include plasmids containing transgenes, oligonucleotides, aptamers, ribozymes, DNAzymes, and small interfering RNAs. Although only 2 DNA-based pharmaceuticals (an antisense oligonucleotide formulation, Vitravene, (USA, 1998), and an adenoviral gene therapy treatment, Gendicine (China, 2003), have received approval from regulatory agencies; numerous candidates are in advanced stages of human clinical trials. Selection of drugs on the basis of DNA sequence and structure has a reduced potential for toxicity, should result in fewer side effects, and therefore should eventually yield safer drugs than those currently available. These predictions are based on the high selectivity and specificity of such molecules for recognition of their molecular targets. However, poor cellular uptake and rapid in vivo degradation of DNA-based therapeutics necessitate the use of delivery systems to facilitate cellular internalization and preserve their activity. This review discusses the basis of structural design, mode of action, and applications of DNA-based therapeutics. The mechanisms of cellular uptake and intracellular trafficking of DNA-based therapeutics are examined, and the constraints these transport processes impose on the choice of delivery systems are summarized. Finally, the development of some of the most promising currently available DNA delivery platforms is discussed, and the merits and drawbacks of each approach are evaluated