Gene expression quantification using reverse transcription–quantitative polymerase chain reaction (RT–qPCR) requires data normalization using an invariable reference gene. Here we assessed the ...stability of 15 housekeeping genes in 31 tumor and normal rectal samples to validate a reliable reference gene for rectal cancer studies. Our data show that
18S and
28S RNA are stably expressed in all samples. Moreover, when used for normalization,
18S, but not
28S, greatly reduced unspecific variations of gene expression due to RNA degradation. These results demonstrate that
18S is an appropriate reference gene for normalization of RT–qPCR data from rectal cancer samples.
125I-labeled monoclonal antibodies (125I-mAbs) can efficiently treat small solid tumors. Here, we investigated the role of apoptosis, autophagy and mitotic catastrophe in 125I-mAb toxicity in p53−/− ...and p53+/+ cancer cells.
We exposed p53−/− and p53+/+ HCT116 cells to increasing activities of internalizing (cytoplasmic location) anti-HER1 125I-mAbs, or non-internalizing (cell surface location) anti-CEA 125I-mAbs. For each targeting model we established the relationship between survival and mean nucleus absorbed dose using the MIRD formalism.
In both p53−/− and p53+/+ HCT116 cells, anti-CEA 125I-mAbs were more cytotoxic per Gy than anti-HER1 125I-mAbs. Sensitivity to anti-CEA 125I-mAbs was p53-independent, while sensitivity to anti-HER1 125I-mAbs was higher in p53−/− HCT 116 cells, suggesting that they act through different signaling pathways. Apoptosis was only induced in p53+/+ HCT116 cells and could not explain cell membrane radiation sensitivity. Inhibition of autophagy did not modify the cell response to 125I-mAbs. By contrast, mitotic death was similarly induced in both p53−/− and p53+/+ HCT116 cells by the two types of 125I-mAbs. We also showed using medium transfer experiments that γ-H2AX foci were produced in bystander cells.
Cell membrane sensitivity to 125I-mAbs is not mediated by apoptosis and is p53-independent. Bystander effects-mediated mitotic death could be involved in the efficacy of 125I-mAbs binding cell surface receptors.
The analytical and clinical validation of new biomarkers for the early detection of prostate is necessary. (-2)proPSA, total PSA and free PSA values are used to calculate a standardized PHI index ...linked to a higher probability of a positive biopsy in patients with PSA levels between 3-4 and 10 ng/L, the gray zone for prostate cancer diagnosis. The purpose of this study is to validate the analytical performance of the (-2)proPSA and to determine the predictive value of PHI for the early detection of prostate cancer. Analytical performances are correct. It is not necessary to dilute samples before analysis. The stability of (-2)proPSA is good until at least 3 hours at room temperature before centrifugation. The study of the PSAT, PSAL, (-2)proPSA and PHI values in a population of patients consulting for an early prostate cancer diagnosis shows that the index PHI is the most powerful predictive marker of cancer with an area under ROC curve of 0.70, whereas it is only 0.56 for total PSA.
We assessed the efficiency and toxicity of brief intraperitoneal radioimmunotherapy using high activities of (125)I-labeled monoclonal antibody (mAb) in the treatment of small-volume peritoneal ...carcinomatosis.
Brief intraperitoneal radioimmunotherapy consisted of a 185-MBq (740 MBq/mg) intraperitoneal injection of (125)I-35A7 (an anti-carcinoembryonic antigen mAb) into athymic nude mice 4 d after peritoneal tumor xenografting and, after 1 h, abundant washing of the peritoneal cavity with saline solution to remove unbound radioactivity. Another group of mice received this treatment plus a 37-MBq intravenous injection of (125)I-35A7 on day 7 or 11 after grafting. Control groups received a brief treatment followed by an additional intravenous injection on day 7 of either saline solution or irrelevant (125)I-PX. Tumor growth was monitored by bioluminescence imaging and SPECT/CT, and hematologic toxicity was evaluated by complete blood counts. Survival time was reported, and the mice were sacrificed when the bioluminescence signal reached 4.5 × 10(7) photons/s. The biodistribution of (125)I-35A7 mAb after intravenous or brief treatment was assessed, and the mean absorbed irradiation dose by organs and tumors was calculated using the MIRD formalism.
Mild, transient hematologic toxicity was observed after the brief treatment plus intravenous (125)I-mAb, with no weight loss. Median survival increased from 32 d in the control groups, to 46 d in the brief treatment group, to 66 d in the group additionally receiving intravenous treatment on day 11, to 73 d in the group additionally receiving intravenous treatment on day 7. The brief treatment alone resulted in a 3-fold higher tumor-to-blood uptake ratio than did the standard intravenous treatment, and the mean absorbed irradiation doses by tumors were 11.6 Gy for the brief treatment and 16.7 Gy for the additional intravenous treatment. For healthy tissues other than blood, the mean absorbed irradiation dose did not exceed 1 Gy after brief treatment and 4.2 Gy after intravenous treatment.
The efficiency, low toxicity, and high tumor-to-healthy tissue uptake ratio associated with brief intraperitoneal (125)I-35A7 radioimmunotherapy suggest that this method can be used in combination with radiation-synergistic drugs in the therapy of small-volume peritoneal carcinomatosis after cytoreductive surgery.
Gene expression quantification using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) requires data normalization using an invariable reference gene. Here we assessed the ...stability of 15 housekeeping genes in 31 tumor and normal rectal samples to validate a reliable reference gene for rectal cancer studies. Our data show that 18S and 28S RNA are stably expressed in all samples. Moreover, when used for normalization, 18S, but not 28S, greatly reduced unspecific variations of gene expression due to RNA degradation. These results demonstrate that 18S is an appropriate reference gene for normalization of RT-qPCR data from rectal cancer samples.
We have previously shown that, in vitro, monoclonal antibodies (mAbs) labeled with the Auger electron emitter (125)I are more cytotoxic if they remain at the cell surface and do not internalize in ...the cytoplasm. Here, we assessed the in vivo biologic efficiency of internalizing and noninternalizing (125)I-labeled mAbs for the treatment of small solid tumors.
Swiss nude mice bearing intraperitoneal tumor cell xenografts were injected with 37 MBq (370 MBq/mg) of internalizing (anti-HER1) (125)I-m225 or noninternalizing (anti-CEA) (125)I-35A7 mAbs at days 4 and 7 after tumor cell grafting. Nonspecific toxicity was assessed using the irrelevant (125)I-PX mAb, and untreated controls were injected with NaCl. Tumor growth was followed by bioluminescence imaging. Mice were sacrificed when the bioluminescence signal reached 4.5 x 10(7) photons/s. Biodistribution analysis was performed to determine the activity contained in healthy organs and tumor nodules, and total cumulative decays were calculated. These values were used to calculate the irradiation dose by the MIRD formalism.
Median survival (MS) was 19 d in the NaCl-treated group. Similar values were obtained in mice treated with unlabeled PX (MS, 24 d) and 35A7 (MS, 24 d) or with (125)I-PX mAbs (MS, 17 d). Conversely, mice treated with unlabeled or labeled internalizing m225 mAb (MS, 76 and 77 d, respectively) and mice injected with (125)I-35A7 mAb (MS, 59 d) showed a significant increase in survival. Irradiation doses were comparable in all healthy organs, independently from the mAb used, whereas in tumors the irradiation dose was 7.4-fold higher with (125)I-labeled noninternalizing than with internalizing mAbs. This discrepancy might be due to iodotyrosine moiety release occurring during the catabolism of internalizing mAbs associated with high turnover rate.
This study indicates that (125)I-labeled noninternalizing mAbs could be suitable for radioimmunotherapy of small solid tumors and that the use of internalizing mAbs should not be considered as a requirement for the success of treatments with (125)I Auger electrons.
Health-related quality of life is often an endpoint in oncology clinical trials. The European Organization for Research and Treatment of Cancer (EORTC) developed the cancer-specific quality of life ...questionnaire (QLQ-C30), which includes five functions, nine symptoms, and a global health status. These questionnaires are completed by the patients themselves throughout the process of care. The recommended approaches for processing EORTC QLQ-C30 data are usually descriptive and graphic.
Ovarian cancer has the highest mortality rate among gynecologic malignancies. The monoclonal antibody 12G4 specifically recognizes the human Müllerian inhibiting substance type II receptor (MISRII) ...that is strongly expressed in human granulosa cell tumors (GCT) and in the majority of human epithelial ovarian cancers (EOC). To determine whether MISRII represents an attractive target for antibody-based tumor therapy, we first confirmed by immunohistochemistry with 12G4 its expression in all tested GCT samples (4/4) and all, but one, EOC human tissue specimens (13/14). We then demonstrated in vitro the internalization of 12G4 in MISRII
high
COV434 cells after binding to MISRII and its ability to increase the apoptosis rate (FACS, DNA fragmentation) in MISRII
high
COV434 (GCT) and MISRII
medium
NIH-OVCAR-3 (EOC) cells that express different levels of MISRII. A standard
51
Cr release assay showed that 12G4 mediates antibody-dependent cell-meditated cytotoxicity. Finally, in vivo assessment of 12G4 anti-tumor effects showed a significant reduction of tumor growth and an increase of the median survival time in mice xenografted with MISRII
high
COV434 or MISRII
medium
NIH-OVCAR-3 cells and treated with 12G4 in comparison to controls treated with an irrelevant antibody. Altogether, our data indicate that MISRII is a new promising target for the control of ovarian GCTs and EOCs. A humanized version of the 12G4 antibody, named 3C23K, is in development for the targeted therapy of MISRII-positive gynecologic cancers.
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