Highly-succinylated N-succinyl-chitosan (Suc) was fluorescein-labeled, and the labeled product (Suc-FTC) was examined for biodisposition in Sarcoma 180-bearing mice after i.v. and i.p. administration. Suc-FTC injected intravenously was sustained at a high level in the blood circulation and showed little distribution to tissues other than tumor. On the other hand, it took a few hours for Suc-FTC to be transferred to the blood circulation after i.p. administration. There were no marked differences in the distribution of Suc-FTC between i.v. and i.p. administration routes except in the early stage. The urinary excretion of Suc-FTC following both i.v. and i.p. administration was small, but the excretion tended to be suppressed after i.p. administration. Water-soluble Sucmitomycin C conjugate (Suc-MMC) prepared using water-soluble carbodiimide exhibited marked effect at a high dose and suppressed the acute toxic side effect of MMC. Suc-MMC tended to be more toxic at i.p. administration than at i.v. administration. The difference in biodisposition between the two administrations was thought to affect the toxic side effect. The plasma levels of conjugated and free MMCs at 8 h after i.v. administration were higher than those at 8 h after i.p. administration. These suggested more localization of the conjugate in peripheral tissues and less excretion at i.p. administration, which might result in greater toxicity.
Abstract Abstract: Novel 8-hydroxy-4-oxochroman derivatives were prepared from appropriate 4-chromanones via the Baeyer-Villiger oxidation followed by an intramolecular Fries rearrangement.
Therapies for liver cancer particularly those including radiation are still inadequate. Inhibiting the stress response machinery is an appealing anti-cancer and radiosensitizing therapeutic strategy. Heat-shock-protein-90 (HSP90) is a molecular chaperone that is a prominent effector of the stress response machinery and is overexpressed in liver cancer cells. HSP90 client proteins include critical components of pathways implicated in liver cancer cell survival and radioresistance. The effects of a novel non-geldanamycin HSP90 inhibitor, ganetespib, combined with radiation were examined on 3 liver cancer cell lines, Hep3b, HepG2 and HUH7, using in vitro assays for clonogenic survival, apoptosis, cell cycle distribution, γH2AX foci kinetics and client protein expression in pathways important for liver cancer survival and radioresistance. We then evaluated tumor growth delay and effects of the combined ganetespib-radiation treatment on tumor cell proliferation in a HepG2 hind-flank tumor graft model. Nanomolar levels of ganetespib alone exhibited liver cancer cell anti-cancer activity in vitro as shown by decreased clonogenic survival that was associated with increased apoptotic cell death, prominent G2-M arrest and marked changes in PI3K/AKT/mTOR and RAS/MAPK client protein activity. Ganetespib caused a supra-additive radiosensitization in all liver cancer cell lines at low nanomolar doses with enhancement ratios between 1.33-1.78. These results were confirmed in vivo, where the ganetespib-radiation combination therapy produced supra-additive tumor growth delay compared with either therapy by itself in HepG2 tumor grafts. Our data suggest that combined ganetespib-radiation therapy exhibits promising activity against liver cancer cells, which should be investigated in clinical studies.
BACKGROUND: Endocan was reported to affect breast cancer patients negatively and was able to be detected from patients’ blood. OBJECTIVE: This study aimed to investigate if the measurement of blood endocan in breast cancer patients with high ESM1 expression could be an effective tool to detect postoperative recurrence compared with existing tumor markers. METHODS: Blood was collected before and after the tumor resection from the mouse models of breast cancer, and endocan levels were measured while visualizing metastatic recurrence with noninvasive luminescence imaging. In clinical settings, blood was withdrawn from 16 breast cancer patients before and after the tumor resection, and the effect of lumpectomy on blood endocan level was evaluated. Additionally, the blood endocan from 20 patients diagnosed with postoperative recurrence was measured, and their positivity rate for endocan was compared with that for serum carcinoembryonic antigen (CEA) or cancer antigen 15-3 (CA15-3). RESULTS: Our preclinical and clinical experiments revealed that blood endocan levels reflected tumor burden. Furthermore, over 60% of patients suffering from postoperative recurrence who tested negative for CEA or CA15-3 were positive for endocan. CONCLUSIONS: Our results support the clinical significance of endocan in breast cancer patients for detecting breast cancer recurrence.
Poor drug delivery to brain tumors caused by aberrant tumor vasculature and a partly intact blood-brain barrier (BBB) and blood-brain tumor barrier (BTB) can significantly impair the efficacy of chemotherapy. Determining drug delivery to brain tumors is a challenging problem, and the noninvasive detection of drug directly in the tumor can be critically important for accessing, predicting, and eventually improving effectiveness of therapy. In this study, in vivo magnetic resonance spectroscopy (MRS) was used to detect an anticancer agent, temozolomide (TMZ), in vivo in murine xenotransplants of U87MG human brain cancer. Dynamic magnetic resonance imaging (MRI) with the low-molecular-weight contrast agent, gadolinium diethylenetriaminepentaacetic acid (GdDTPA), was used to evaluate tumor vascular parameters. Carbon-13-labeled TMZ ([13C]TMZ, 99%) was intraperitoneally administered at a dose of ∼140 mg/kg (450 mg/m2, well within the maximal clinical dose of 1000 mg/m2 used in humans) during the course of in vivo MRS experiments. Heteronuclear multiple-quantum coherence (HMQC) MRS of brain tumors was performed before and after i.p. administration of [13C]TMZ. Dynamic MRI experiments demonstrated slower recovery of MRI signal following an intravenous bolus injection of GdDTPA, higher vascular flow and volume obtained by T*2-weighted MRI, as well as enhanced uptake of the contrast agent in the brain tumor compared with normal brain detected by T1-weighted MRI. These data demonstrate partial breakdown of the BBB/BTB and good vascularization in U87MG xenografts. A [13C]TMZ peak was detected at 3.9 ppm by HMQC from a selected volume of about 0.15 cm3 within the brain tumor with HMQC pulse sequences. This study clearly demonstrates the noninvasive detection of [13C]TMZ in xenografted U87MG brain tumors with MRS. Noninvasive tracking of antineoplastic agents using MRS can have a significant impact on brain tumor chemotherapy.
Abstract (S)-γ-carboxymethylbutanolide (4) is a key oxidative degradation product of agrimonolide in the determination of the absolute configuration of the latter natural product.1 We wish to communicate a novel and symple one step preparation of racemic γ-carboxymethlbutanolide (2), resolution of which, and determination of the absolute configuration of the obtained (−)-γ-carboxymethylbutanolide (3).
