Mass balance,excretion and metabolism of [<Superscript>14</Superscript>C] ASA404 in cancer patients in a phase I trial

Purpose  

To determine the mass balance, excretion and metabolism of the small molecule flavonoid tumour vascular disrupting agent ASA404 in patients with advanced cancer.     

Metabolic assessment of monofocal acute inflammatory demyelination using MR spectroscopy and <Superscript>11</Superscript>C-methionine-, <Superscript>11</Superscript>C-choline-, and <Superscript>18</Superscript>F-fluorodeoxyglucose-PET

Monofocal acute inflammatory demyelination (MAID), which is observable by CT and MRI as a well-enhanced mass lesion with prominent perifocal edema, is very similar to malignant gliomas radiologically, making differential diagnosis of the two pathologies difficult. The aim of this study was to assess the different metabolic activities between MAID and malignant gliomas by MRS, methionine-PET, choline-PET, and FDG-PET. Six patients with MAID underwent methionine, choline, and FDG-PET, and 4 of the patients also underwent magnetic resonance spectroscopy (MRS). The images obtained from these patients were compared with the corresponding images of 19 anaplastic astrocytomas (AA) and 21 glioblastomas (GBM). The mean choline/creatine ratio of MAID was significantly lower than that of GBM. There were no significant differences in the mean NAA/creatine and lactate/creatine ratios among these pathologies. The methionine T/N ratio of MAID was significantly lower than those of AA and GBM. The choline T/N ratio of MAID was significantly lower than that of GBM. There were no significant differences in the FDG T/N ratios among these pathologies. These results demonstrate that the metabolic activity of MAID significantly differs in part from that of malignant gliomas. Combined PET and MRS neuroimaging examinations may be useful for differential diagnosis of these pathologies.     

Assessment of the absorption, metabolism and excretion of [14C]pasireotide in healthy volunteers using accelerator mass spectrometry

Purpose

Pasireotide (SOM230) is a multireceptor-targeted somatostatin analog designed to have a broader somatostatin receptor binding profile than other currently available somatostatin analogs. The purpose of this study was to evaluate the absorption, metabolism and excretion of pasireotide in healthy male subjects (N = 4) following a single, subcutaneous (sc), 600 μg dose of [¹⁴C]pasireotide.

Methods

Blood, plasma, urine and feces were collected for 240 h post-dose and analyzed for total ¹⁴C and metabolite profile by accelerator mass spectrometry (AMS) or high-performance liquid chromatography–AMS. Parent drug levels were analyzed by radioimmunoassay.

Results

[¹⁴C]pasireotide was rapidly absorbed, with a mean peak plasma ¹⁴C concentration of 16.6 ± 5.28 ngEq/mL at 0.5 h in plasma. The parent drug to total ¹⁴C AUC_0–24h ratio was 1.08, indicating that little metabolite was present in plasma up to 24 h post-dose. In pooled plasma samples (0–12 h), only unchanged [¹⁴C]pasireotide was detected. Unchanged [¹⁴C]pasireotide accounted for approximately 84 % of total excretion (feces and urine). Approximately 56 % of the administered radioactive dose was recovered within 240 h, eliminated primarily in feces (48.3 ± 8.16 %) and minimally in urine (7.63 ± 2.03 %). No serious adverse events were reported.

Conclusions

A single dose of [¹⁴C]pasireotide 600 μg sc administered to healthy male subjects was rapidly absorbed and excreted in its unchanged form primarily via the hepatic route.     

Plasma and CNS pharmacokinetics of O<Superscript>4</Superscript>-benzylfolic acid (O<Superscript>4</Superscript>BF) and metabolite in a non-human primate model

Purpose  

O⁶-alkylguanine-DNA alkyltransferase (AGT) repairs DNA damage from alkylating agents by transferring the alkyl adducts from the O⁶-position of guanine in DNA to AGT. The folate analog O⁴-benzylfolic acid (O⁴BF) is an inhibitor of AGT with reported selectivity of the alpha-folate receptor in tumors. We studied plasma and cerebrospinal fluid (CSF) pharmacokinetics and CSF penetration of O⁴BF in a non-human primate model.     

Immunohistochemical Analysis of Foxp3<Superscript>+</Superscript>, CD4<Superscript>+</Superscript>, CD8<Superscript>+</Superscript> Cell Infiltrates and PD-L1 in Oral Squamous Cell Carcinoma

The immunoexpression of the PD-L1 and the number of immune infiltrating cells have been shown to be a significant prognostic factors in various human cancers. Immunohistochemical method was used to examine the immunoexpression of PD-L1 and number of Foxp3+, CD4+, CD8+ cells in 78 cases of oral squamous cell carcinomas (OSCCs): with better prognosis - OSCCBP (n = 37), and with poorer prognosis - OSCCPP (n = 41), and 18 cases of normal mucosa as a control. The immunoexpression of PD-L1 and the mean number of Foxp3+ cells was significantly increased in OSCCPP group in comparison to OSCCBP and control groups. The mean number of CD4+ cells was significantly increased in OSCCPP group in comparison to OSCCBP and control groups. CD8+ cells were significantly more numerous in OSCCBP group in comparison to OSCCPP and control group. In both OSCCPP and OSCCBP groups there were positive significant correlations between number of Foxp3+ and CD4+ cells. We found positive correlations between the immunoexpression of PD-L1 and numbers of Foxp3+ cells, and negative correlation between the immunoexpression of PD-L1 and numbers of CD8+ cells in both OSCCPP and OSCCBP groups. We found also significant positive correlation between immunoexpression of PD-L1 and the number of CD4+ cells in OSCCPP group. In conclusion, our findings support the hypothesis of involvement of Tregs and PD-L1 in OSCC development and progression.     

Over-expression of Na<Superscript>+</Superscript>/H<Superscript>+</Superscript> exchanger 1 and its clinicopathologic significance in hepatocellular carcinoma

The activation of Na⁺/H⁺ exchanger 1 (NHE1) is involved in the formation of tumor cell pseudopodia, possibly resulting in their malignant potential. The clinicopathological significance of NHE1, however, is not yet well known in the case of hepatocellular carcinoma (HCC). In this study, we first analyzed the NHE1 expression in 100 cases of hepatocellular carcinoma (HCC) and found that NHE1, at both messenger RNA and protein levels, was over-expressed in majority of HCC tissues compared with matched non-cancerous tissue. In addition, the increased expression of NHE1 correlated with tumor size, venous invasion and advanced pTNM stage (P < 0.05). Kaplan–Meier curves demonstrated that patients with increased NHE1 expression were at significantly increased risk for shortened survival time (P < 0.05). This is the first demonstration that the expression level of NHE1 is correlated with tumor progression and prognosis in HCC. We proposed that NHE1 may have diagnostic and therapeutic potential for patients with HCC.     

Comparative study of<Superscript>99m</Superscript>TcN (NOEt)<Subscript>2</Subscript> and<Superscript>99m</Superscript>Tc-MIBI imaging in mice bearing Ehrlich ascites tumor

Objective To evaluate and compare the ability to detect tumor by bis (N-ethoxy-N-ethyl dithiocarbamato) nitrido^99mTc(V) [^99mTcN(NOEt)₂] and^99mTc hexakis-2- methoxyisobutyl isonitrile [^99mTc-MIBI]. Methods ^99mTcN(NOEt)₂ was prepared and quality control was performed using ascending thin-layer chromatography. Four mice bearing Ehrich ascites tumor cells underwent whole body planar imaging at 30 min, 2 h and 4 h after injection of^99mTc-MIBI or^99mTcN(NOEt)₂. ROIs were drawn around the tumor, head, chest, and contralateral limbs in whole body planar images, and ratios of radioactivity in tumor in head (T/H), chest (T/C), and contralateral limbs (T/L) were calculated. The mice of^99mTcN (NOEt)₂ group were killed, then blood was collected, and the tumor and organs were excised, weighed and the radioactivity was measured. Results ^99mTcN(NOEt)₂ was stable after 4h at the room temperature.^99mTcN(NOEt)₂ was delivered to the tumor selectively and efficiently.^99mTcN(NOEt)₂ was found to provide excellent tumor-to-nontumor contrast for all the tissue except the abdomen. The T/L ratios increased to their maximums (4.87) at 2 h after injection. There was significant difference between the^99mTcN(NOEt)₂ imaging group and^99mTc-MIBI imaging group. In vitro the radioactivity ratios per unit weight of tumor to blood, muscle, skeleton, lung, heart, and spleen were much higher than those of tumor to liver, instestine. Conclusion In mice bearing Ehrich ascites tumor,^99mTcN(NOEt)₂ exhibits a set of features essential for a good tracer for tumor imaging, including a rapid washout from blood, high uptake rate in tumor tissue, prolonged retention and high tumor-to-nontumor uptake ratio. The imaging quality of^99mTcN(NOEt)₂ was superior to that of^99mTc-MIBI. These features indicate that^99mTcN(NOEt)₂ may be a better tracer to detect tumor than^99mTc-MIBI.     

Effect of Homoharringtonine on Bone Morrow CD34^＋CD7^＋ Cells in Chronic Granulocytic Leukemia

Objective： To explore the effect of homoharringtonine （HHT） on bone morrow CD34^＋CD7^＋ cells in chronic granulocytic leukemia （CGL）. Methods： The changes of bone morrow CD34^＋CD7^＋ cells were observed after the treatment of HHT in 23 cases with CGL. The proliferation and apoptosis of CD34^＋CD7^＋ cells treated with HHT in vitro were studied. Results： The proportion of CD34^＋CD7^＋ cells in CGL （0.145±0.021） was higher than that of normal control （0.052±0.013）. The proportion of CD34^＋CD7^＋ cells in patients who got cytogenetic responses to HHT （0.072±0.020） decreased remarkably, but not in those patients who did not got cytogenetic responses to HHT, （0.137±0.023）. the proliferation of CD34^＋ cells was inhibited and the proportion of CD34^＋CD7^＋ cells decreased after cultured with HHT （0.134 in 24 h, 0.126 in 48 h and 0.102 in 72）. The apoptosis rate of CD34^＋CD7^＋ cells was higher than that in CD34^＋CDT cells （35.39%±4.39% versus 24.57%±4.01%, P〈0.05） 72 h after culture with HHT. Conclusion： The proportion of CD34^＋CD7^＋ cells in CGL was higher than that of normal control and HHT may inhibit the proliferation and induce apoptosis of bone marrow CD34^＋CD7^＋ cells.     

Role of Na<Superscript>+</Superscript>/H<Superscript>+</Superscript> exchanger in resveratrol-induced growth inhibition of human breast cancer cells

Cancer cells maintain low intracellular pH [pHi]; therefore, it is likely that resveratrol [RSVL] inhibits cell growth through interference with regulation of pHi. Na–H exchanger [NHE] regulates pHi and NaCl uptake. In this study, we investigated a putative role of NHE-1 and NHE-3 isoforms in the RSVL-induced cell death using MDA-MB-231 estrogen receptor-negative [ER−] and MCF-7 [ER+] human breast cancer cell lines. ECL Western blot analysis and fluorescence morphometeric analysis were used. Cell viability and counting were performed using standard procedures. RSVL caused a dose- and time-dependent induction of NHE-1 and NHE-3 proteins in both cancer cell lines as shown by ECL Western blot analysis and fluorescence measurement. Interestingly, the level of actin, an internal control, remains unaltered. Thus, it is concluded that RSVL-inhibited cell growth and viability, increased cell size, and volume along with an increased apoptotic activity are due to the induction of NHE-1 and NHE-3 isoforms in the present breast cancer cell lines. Induction of NHE will increase the uptake of NaCl and decrease pHi leading to disturbance in Ca²⁺ homeostasis, which is responsible for cell death.     

Usefulness of <Superscript>13</Superscript>N-NH<Subscript>3</Subscript> PET in the evaluation of brain lesions that are hypometabolic on <Superscript>18</Superscript>F-FDG PET

We investigated the usefulness of ¹³N-NH₃ PET in characterizing brain lesions which show hypometabolism on ¹⁸F-FDG PET. ¹³N-NH₃ PET was performed in 18 patients with brain lesions (in 14 for initial diagnosis and in 4 for detection of astrocytoma recurrence) that showed hypometabolism compared with normal brain tissue on ¹⁸F-FDG PET. The diagnoses were ten gliomas, one metastatic tumor, one dysembryoplastic neuroepithelial tumor (DNT), and six non-neoplastic lesions (including three cases of radiation necrosis, two cases of encephalitic foci, and one ischemic lesion). Diagnosis was verified by histopathological examination in 13 patients or was established by clinical follow-up and additional investigations in the remainder. Seven of 12 brain tumors (58%, sensitivity) showed increased ¹³N-NH₃ uptake despite hypometabolism on ¹⁸F-FDG PET. The three low-grade gliomas, one metastatic tumor, and one DNT showed decreased ¹³N-NH₃ uptake. The mean (±SD) uptake ratio of ¹³N-NH₃ was significantly higher than that of ¹⁸F-FDG (1.24 ± 0.57 vs. 0.67 ± 0.21, P < 0.01) in the tumors. By contrast, all six non-neoplastic lesions showed decreased ¹³N-NH₃ uptake (100% specificity). The mean (±SD) uptake ratio of ¹⁸F-FDG and ¹³N-NH₃ in the non-neoplastic lesions was 0.68 ± 0.15 and 0.70 ± 0.19, respectively, and there was no significant difference between them (P > 0.05). The mean (±SD) uptake ratio of ¹³N-NH₃ in the tumors was significantly higher than that in the non-neoplastic lesions (1.24 ± 0.53 vs. 0.70 ± 0.19, P < 0.05). The preliminary results of this study suggest that ¹³N-NH₃ PET may be helpful to detect and differentiate brain tumors which show hypometabolism on ¹⁸F-FDG PET from non-neoplastic lesions with high specificity, especially for cerebral astrocytomas, but the sensitivity is relatively limited.     

Characterization of the distribution,retention, and efficacy of internal radiation of <Superscript>188</Superscript>Re-lipid nanocapsules in an immunocompromised human glioblastoma model

Internal radiation strategies hold great promise for glioblastoma (GB) therapy. We previously developed a nanovectorized radiotherapy that consists of lipid nanocapsules loaded with a lipophilic complex of Rhenium-188 (LNC¹⁸⁸Re-SSS). This approach resulted in an 83?% cure rate in the 9L rat glioma model, showing great promise. The efficacy of LNC¹⁸⁸Re-SSS treatment was optimized through the induction of a T-cell immune response in this model, as it is highly immunogenic. However, this is not representative of the human situation where T-cell suppression is usually encountered in GB patients. Thus, in this study, we investigated the efficacy of LNC¹⁸⁸Re-SSS in a human GB model implanted in T-cell deficient nude mice. We also analyzed the distribution and tissue retention of LNC¹⁸⁸Re-SSS. We observed that intratumoral infusion of LNCs by CED led to their complete distribution throughout the tumor and peritumoral space without leakage into the contralateral hemisphere except when large volumes were used. Seventy percent of the ¹⁸⁸Re-SSS activity was present in the tumor region 24 h after LNC¹⁸⁸Re-SSS injection and no toxicity was observed in the healthy brain. Double fractionated internal radiotherapy with LNC¹⁸⁸Re-SSS triggered survival responses in the immunocompromised human GB model with a cure rate of 50?%, which was not observed with external radiotherapy. In conclusion, LNC¹⁸⁸Re-SSS can induce long-term survival in an immunosuppressive environment, highlighting its potential for GB therapy.     

Absorption, metabolism and excretion of [14C]pomalidomide in humans following oral administration

Purpose

To investigate the pharmacokinetics and disposition of [¹⁴C]pomalidomide following a single oral dose to healthy male subjects.

Methods

Eight subjects were administered a single 2 mg oral suspension of [¹⁴C]pomalidomide. Blood (plasma), urine and feces were collected. Mass balance of radioactivity and the pharmacokinetics of radioactivity, pomalidomide and metabolites were determined. Metabolite profiling and characterization was performed. The enzymes involved in pomalidomide metabolism and the potential pharmacological activity of metabolites were evaluated in vitro.

Results

Mean recovery was 88 %, with 73 and 15 % of the radioactive dose excreted in urine and feces, respectively, indicating good oral absorption. Mean C _max, AUC_0?∞ and t _max values for pomalidomide in plasma were 13 ng/mL, 189 ng*h/mL and 3.0 h. Radioactivity and pomalidomide were rapidly cleared from circulation, with terminal half-lives of 8.9 and 11.2 h. Pomalidomide accounted for 70 % of the circulating radioactivity, and no circulating metabolite was present at >10 % of parent compound. Pomalidomide was extensively metabolized prior to excretion, with excreted metabolites being similar to those observed in circulation. Clearance pathways included cytochrome P450-mediated hydroxylation with subsequent glucuronidation (43 % of the dose), glutarimide ring hydrolysis (25 %) and excretion of unchanged drug (10 %). 5-Hydroxy pomalidomide, the notable oxidative metabolite, was formed primarily via CYP1A2 and CYP3A4. The hydroxy metabolites and hydrolysis products were at least 26-fold less pharmacologically active than pomalidomide in vitro.

Conclusions

Following oral administration, pomalidomide was well absorbed, with parent compound being the predominant circulating component. Pomalidomide was extensively metabolized prior to excretion, and metabolites were eliminated primarily in urine.     

Expression of p21<Superscript>waf1/cip1</Superscript>, p27<Superscript>kip1</Superscript>, p63 and Androgen Receptor in Low and High Gleason Score Prostate Cancer

The aim of this study was to investigate the expression of p21^waf1/cip1, p27^kip1, p63 and androgen receptor proteins in relation to serum prostate specific antigen levels in low and high Gleason score prostate cancers. Biopsies of patients suffering from prostate adenocarcinoma of low (3 + 3 to 3 + 4) and high (5 + 4 to 5 + 5) Gleason scores (13 cases each group) were immunostained for positive regulators of cell cycle control (p21^waf1/cip1 and p27^kip1), and essential markers of normal prostate gland ontogeny (p63) and growth (androgen receptor) to find differentially expressed markers of malignant progression. Serum prostate specific antigen levels were also monitored at the time of biopsy and following anti-androgen therapy. All cases except one in each group were androgen receptor positive. P63 and p21^waf1/cip1 proteins detected in normal basal cell nuclei were lost in all but one studied tumors respectively. P27^kip1 protein, however, was detected in all low Gleason score prostate cancers, but it was found in only 7/13 high score cases. Prostate specific antigen levels, either pre- or post-treatment, did not show strict correlation with the p27^kip1 results. The low to high grade dedifferentiation of prostate adenocarcinoma is accompanied with the down-regulation of p27^kip1 protein, which may be an important molecular sign of the lost cell cycle control.     

Changes in cerebral metabolism during ketogenic diet in patients with primary brain tumors: <Superscript>1</Superscript>H-MRS study

Pediatric posterior fossa (PF) tumor survivors experience long-term motor deficits. Specific cerebrocerebellar connections may be involved in incidence and severity of motor dysfunction. We examined the relationship between long-term ataxia as well as fine motor function and alteration of differential cerebellar efferent and afferent pathways using diffusion tensor imaging (DTI) and tractography. DTI-based tractography was performed in 19 patients (10 pilocytic astrocytoma (PA) and 9 medulloblastoma patients (MB)) and 20 healthy peers. Efferent Cerebello-Thalamo-Cerebral (CTC) and afferent Cerebro-Ponto-Cerebellar (CPC) tracts were reconstructed and analyzed concerning fractional anisotropy (FA) and volumetric measurements. Clinical outcome was assessed with the International Cooperative Ataxia Rating Scale (ICARS). Kinematic parameters of fine motor function (speed, automation, variability, and pressure) were obtained by employing a digitizing graphic tablet. ICARS scores were significantly higher in MB patients than in PA patients. Poorer ICARS scores and impaired fine motor function correlated significantly with volume loss of CTC pathway in MB patients, but not in PA patients. Patients with pediatric post-operative cerebellar mutism syndrome showed higher loss of CTC pathway volume and were more atactic. CPC pathway volume was significantly reduced in PA patients, but not in MB patients. Neither relationship was observed between the CPC pathway and ICARS or fine motor function. There was no group difference of FA values between the patients and healthy peers. Reduced CTC pathway volumes in our cohorts were associated with severity of long-term ataxia and impaired fine motor function in survivors of MBs. We suggest that the CTC pathway seems to play a role in extent of ataxia and fine motor dysfunction after childhood cerebellar tumor treatment. DTI may be a useful tool to identify relevant structures of the CTC pathway and possibly avoid surgically induced long-term neurological sequelae.     

Expression of the Na<Superscript>+</Superscript>/l<Superscript>-</Superscript>symporter (NIS) is markedly decreased or absent in gastric cancer and intestinal metaplastic mucosa of Barrett esophagus

Background  

The sodium/iodide symporter (NIS) is a plasma membrane glycoprotein that mediates iodide (I^-) transport in the thyroid, lactating breast, salivary glands, and stomach. Whereas NIS expression and regulation have been extensively investigated in healthy and neoplastic thyroid and breast tissues, little is known about NIS expression and function along the healthy and diseased gastrointestinal tract.