Philippe Rochaix

Population pharmacokinetics of erlotinib and its pharmacokinetic/pharmacodynamic relationships in head and neck squamous cell carcinoma.

UNLABELLEDnA clinical study was conducted to determine the safety and efficacy of neoadjuvant erlotinib treatment in patients with head and neck squamous cell carcinoma [Thomas F, Rochaix P, Benlyazid A, et al. Pilot study of neoadjuvant treatment with erlotinib in non-metastatic head and neck squamous cell carcinoma. Clin Cancer Res 2007;13:7086-92]. The aim of the present analysis was to explore the impact of several covariates on the pharmacokinetics of erlotinib and its main metabolite (OSI-420) and to determine PK/PD relationships.nnnPATIENTS AND METHODSnPlasma concentrations of erlotinib and OSI-420 of 42 patients were analysed using the NONMEM program to evaluate the impact of patients covariates on erlotinib pharmacokinetics. The presence of single nucleotide polymorphisms (SNP) in ABCB1 (2677G>T/A and 3435C>T), ABCG2 (421C>A) and CYP3A5 (6986G>A) was investigated. Pharmacokinetic/pharmacodynamic relationships between plasma drug exposure (AUC) and early drug response or toxicity were also studied.nnnRESULTSnThe covariates retained to predict erlotinib clearance were ALAT (alanine amino transferase), age and ABCG2 polymorphism. A significant link between drug exposure and the grade of skin rash was observed but early response to treatment was not correlated to the erlotinib AUC.nnnCONCLUSIONSnErlotinib treatment may present criteria justifying dose individualisation but further studies, including more patients, are necessary to define the modalities of this adaptation.

In vivo patterns of bcl-2 family protein expression in breast carcinomas in relation to apoptosis

The expression of the pro‐apoptotic proteins (Bax, Bak) and anti‐apoptotic proteins (Bcl‐2, Bcl‐X, Mcl‐1) was studied by immunohistochemistry in 110 invasive ductal breast carcinomas. The results were correlated with tumour grade, expression of oestrogen receptor (ER) and p53 protein, and the apoptotic index by combined morphology, immunohistochemistry, and a terminal UTP nick end labelling (TUNEL) procedure. Overall, Bcl‐2, Bcl‐X, Mcl‐1, Bax, Bak, ER, and p53 were detected in 62, 75, 68, 75, 60, 68 and 26 per cent of the cases respectively, but at different levels in each case. A high apoptotic index was correlated with high tumour grade (pu2005<u20050·001), overexpression of p53 (pu2005<u20050·001), Bak expression (pu2005<u20050·001), and low expression of Bcl‐2 (pu2005<u20050·001) and ER (pu2005<u20050·001). No correlation was found between the apoptotic index and Bax, Bcl‐X, and Mcl‐1 immunostaining results. The expression of Bcl‐2 and Bcl‐X was correlated to that of ER. Overall, the results of this study strongly suggest that Bcl‐2 and Bak expression is critical in regulating apoptosis in breast carcinomas. Copyright

Inhibition of Rho pathways induces radiosensitization and oxygenation in human glioblastoma xenografts.

We previously demonstrated in vitro that inhibiting the biological pathways of the small GTPase Rho radiosensitizes the human glioma U87 cell line. The aim of this study was to determine if Rho might be involved in the control of in vivo radiosensitivity altogether by controlling cellular radioresistance and by modifying tumor microenvironment. We demonstrate here that the in vivo induction of the dominant negative of Rho, RhoBN19, in U87 xenografts induces a significant decrease of tumor cell survival after irradiation more important than the one we previously observed in vitro. This in vivo increased effect of RhoBN19 expression is due to the improvement of the tumor oxygenation associated with a significant decrease of the vessel density and of the metalloproteinase 2 (MMP2) expression. Moreover, in vitro RhoBN19 expression in U87 cells leads to the inhibition of MMP2 activity. Our results demonstrate for the first time that inhibiting Rho pathways modifies the in vivo radiosensitivity of human glioma cells by controlling intrinsic radioresistance, hypoxia and angiogenesis. These data strongly suggest that Rho should be a major determinant of cellular resistance to ionizing radiation.

KBA.62: a useful marker for primary and metastatic melanomas.

We previously described a novel antimelanoma antibody, designated KBA.62. However, review of the literature showed that only a few studies have reported on this antibody. We report our experience in the diagnosis of melanoma using KBA.62 and its value in both primary and metastatic conditions. In addition to conventional melanomas, we included desmoplastic and spindle cell melanomas, whose diagnosis can be challenging. We also focus on identification of malignant cells in sentinel lymph node biopsies using KBA.62, by comparison with anti-S-100 protein and HMB-45 antibodies, because discrepancies in sensitivity and specificity of melanoma markers have given rise to numerous studies aiming to determine the best panel for the evaluation of sentinel lymph node from patients with melanoma. Overall, KBA.62 was positive in 93% of primary and metastatic melanomas. Interestingly, the 12 cases of desmoplastic and spindle cell melanomas had strongly positive results. In addition, the results of our study performed on a series of 215 sentinel lymph nodes showed that the sensitivity of anti-S-100 protein and KBA.62 antibodies in detecting occult metastasis was similar. Moreover, KBA.62 identified 6 patients (3%) who had confirmed sentinel lymph node metastasis but were negative for HMB-45. The resolution was higher with KBA.62 than that observed with anti-S-100 protein antibody, as the nonmelanocytic positive cells for KBA.62 in lymph nodes were only represented by endothelial cells, which therefore constituted an intrinsic positive control. We conclude that KBA.62 antibody is a useful additional marker for melanoma, specifically in desmoplastic/spindle cell cases and in the context of micrometastasis in sentinel lymph node.

Two antiestrogens affect differently chromatin remodeling of trefoil factor 1 (pS2) gene and the fate of estrogen receptor in MCF7 cells.

We show here that the two antagonists ICI 182 780, a pure estrogen antagonist, and 4-hydroxy-tamoxifen, a selective estrogen receptor modulator (SERM) have distinct effects on TFF1 (formerly pS2) gene chromatin structure and transcription. Indeed, ICI 182 780 decreased both the intensity of the hormone-dependent DNase I hypersensitive site pS2 HS-1 and transcription of the pS2 gene whereas 4-hydroxy-tamoxifen (OH-Tam) increased the intensity of pS2-HS1 and had no effect on pS2 gene transcription. Interestingly, these differential effects are associated with different fates of ERalpha following the two treatments: The ERalpha-OH-Tam complex was retained in the nucleus more efficiently than the ERalpha-estradiol complex. In contrast, ICI 182 780 provoked a rapid relocation of ERalpha complex to an insoluble nuclear fraction, followed by its degradation. Taken together, these data suggest that regulating the amount of ERalpha in the nucleus is a major way of action of estrogen antagonists with respect to chromatin remodeling and transcriptional control.

Statins Reduce Melanoma Development and Metastasis through MICA Overexpression.

Survival of melanoma patients after metastases detection remains short. Several clinical trials have shown moderate efficiency in improving patient survival, and the search for pharmacological agents to enhance the immune response and reduce melanoma metastases is still necessary. Statins block the mevalonate pathway, which leads to decreases in GTPase isoprenylation and activity, particularly those of the Ras superfamily. They are widely used as hypocholesterolemic agents in cardiovascular diseases and several studies have shown that they also have protective effects against cancers. Furthermore, we have previously demonstrated that treatment of melanoma cells with inhibitors of the mevalonate pathway, such as statins, favor the development of specific adaptive immune responses against these tumors. In the present study, we tested statin impact on the innate immune response against human metastatic melanoma cells. Our data shows that treatment of two human melanoma cell lines with statins induced a weak but significant increase of MHC class I Chain-related protein A (MICA) membrane expression. Peroxisome Proliferator-Activated Receptor gamma is involved in this statin-induced MICA overexpression, which is independent of Ras and Rho GTPase signaling pathways. Interestingly, this MICA overexpression makes melanoma cells more sensitive to in vitro lysis by NK cells. The impact of statin treatment on in vivo development of melanoma tumors and metastases was investigated in nude mice, because murine NK cells, which express NKG2D receptors, are able to recognize and kill human tumor cells expressing MICA. The results demonstrated that both local tumor growth and pulmonary metastases were strongly inhibited in nude mice injected with statin-treated melanoma cells. These results suggest that statins could be effective in melanoma immunotherapy treatments.

Role of radiation therapy in the conservative management of sarcoma within an irradiated field.

PURPOSEnTo report on clinical outcome and toxicity profile after combined treatment that included radiation therapy (RT) in patients with localized sarcoma within an irradiated field.nnnPATIENTS AND METHODSnIndividual clinical data from all consecutive patients diagnosed and treated for a localized SIF between January 2000 and October 2011 at the Institut Claudius Regaud, Toulouse, France, were retrospectively reviewed. Outcomes of patients with SIF who underwent adjuvant or definitive radiotherapy were compared with patients who did not receive further RT.nnnRESULTSnOf the 27 patients eligible for this study: surgery alone (S), surgery followed by RT (S + RT) or definitive RT (RT) was performed in 16, 8 and 2 cases respectively. The rate of unresectable, gross or microscopically positive margin disease among the 10 re-irradiated patients was significantly higher than the non re-irradiated group (90% vs. 12% p < 0.001). After a median follow-up of 3.8 years, there was a trend toward longer survival and better local control in the subgroup of patients who received adjuvant or definitive RT compared to the rest of the cohort with an acceptable toxicity profile. The 4-year relapse free survival rates of patients treated with and without RT were 53% and 27% respectively (p = 0.09).nnnCONCLUSIONnSIF complete surgical resection is often difficult to achieve, enhancing the risk of relapse. RT should be discussed in case of unresectable tumor or after suboptimal surgery as part of intensified local management that has a curative intent.

Les nouveaux fixateurs tissulaires

Resume Depuis plus d’un siecle, le formol est la molecule clef de la fixation tissulaire. Pourtant, sa classification recente en produit cancerigene avere et les nouvelles exigences du diagnostic moleculaire ont relance l’interet pour les fixateurs sans formol. Il s’agit d’une vaste famille de produits extremement heterogenes. Cet article decrit les principaux modes d’action de ces produits et propose une classification simple permettant d’orienter le choix des fixateurs a tester en fonction des objectifs recherches.

Gene expression profiling on pre- and post-erlotinib tumors from patients with head and neck squamous cell carcinoma†‡

The purpose of our work was to identify genomic predictive markers of erlotinib response in patients with head and neck squamous cell carcinoma (HNSCC).

Place de la radiothérapie dans le traitement conservateur des sarcomes en territoire irradié

PURPOSEnTo describe long-term outcome after combined-modality treatment including radiation therapy in patients with localized sarcoma within irradiated field.nnnPATIENTS AND METHODSnIndividual clinical data from all consecutive patients diagnosed and treated for a localized sarcoma within irradiated field between January 2000 and October 2011 at the Institut Claudius-Regaud, Toulouse, France, were retrospectively reviewed.nnnRESULTSnTwenty-seven patients were eligible for this study. Ten patients were re-irradiated with a rate of unresectable, gross or microscopically positive margins disease significantly higher than the rest of the cohort (90% vs. 12%; P<0.001). After a median follow-up of 3.8 years, there is a non-significant trend toward longer 4-year relapse free survival in the subgroup of patients who received adjuvant or definitive radiation therapy compared to the rest of the cohort (53% vs. 27%; P=0.09) with an acceptable toxicity profile allowing conservative management.nnnCONCLUSIONnThe complete surgical resection sarcoma within irradiated field is often difficult to achieve enhancing the risk of relapse. Radiation therapy should be discussed when faced with an unresectable tumour or after suboptimal surgery as part of intensified local management with a curative intent.