Phosphoproteomic analysis of neoadjuvant breast cancer suggests that increased sensitivity to paclitaxel is driven by CDK4 and filamin A.

Precision oncology research is challenging outside the contexts of oncogenic addiction and/or targeted therapies. We previously showed that phosphoproteomics is a powerful approach to reveal patient subsets of interest characterized by the activity of a few kinases where the underlying genomics is complex. Here, we conduct a phosphoproteomic screening of samples from HER2-negative female breast cancer receiving neoadjuvant paclitaxel (N = 130), aiming to find candidate biomarkers of paclitaxel sensitivity. Filtering 11 candidate biomarkers through 2 independent patient sets (N = 218) allowed the identification of a subgroup of patients characterized by high levels of CDK4 and filamin-A who had a 90% chance of achieving a pCR in response to paclitaxel. Mechanistically, CDK4 regulates filamin-A transcription, which in turn forms a complex with tubulin and CLIP-170, which elicits increased binding of paclitaxel to microtubules, microtubule acetylation and stabilization, and mitotic catastrophe. Thus, phosphoproteomics allows the identification of explainable factors for predicting response to paclitaxel.

EPB41L3, TSP-1 and RASSF2 as new clinically relevant prognostic biomarkers in diffuse gliomas.

Hypermethylation of tumor suppressor genes is one of the hallmarks in the progression of brain tumors. Our objectives were to analyze the presence of the hypermethylation of EPB41L3, RASSF2 and TSP-1 genes in 132 diffuse gliomas (astrocytic and oligodendroglial tumors) and in 10 cases of normal brain, and to establish their association with the patients' clinicopathological characteristics. Gene hypermethylation was analyzed by methylation-specific-PCR and confirmed by pyrosequencing (for EPB41L3 and TSP-1) and bisulfite-sequencing (for RASSF2). EPB41L3, RASSF2 and TSP-1 genes were hypermethylated only in tumors (29%, 10.6%, and 50%, respectively), confirming their cancer-specific role. Treatment of cells with the DNA-demethylating-agent 5-aza-2'-deoxycytidine restores their transcription, as confirmed by quantitative-reverse-transcription-PCR and immunofluorescence. Immunohistochemistry for EPB41L3, RASSF2 and TSP-1 was performed to analyze protein expression; p53, ki-67, and CD31 expression and 1p/19q co-deletion were considered to better characterize the tumors. EPB41L3 and TSP-1 hypermethylation was associated with worse (p = 0.047) and better (p = 0.037) prognosis, respectively. This observation was confirmed after adjusting the results for age and tumor grade, the role of TSP-1 being most pronounced in oligodendrogliomas (p = 0.001). We conclude that EPB41L3, RASSF2 and TSP-1 genes are involved in the pathogenesis of diffuse gliomas, and that EPB41L3 and TSP-1 hypermethylation are of prognostic significance.

Stromal disrupting effects of nab-paclitaxel in pancreatic cancer.

BACKGROUND: Nab-paclitaxel and gemcitabine have demonstrated a survival benefit over gemcitabine alone in advanced pancreatic cancer (PDA). This study aimed to investigate the clinical, biological, and imaging effects of the regimen in patients with operable PDA. METHODS: Patients with operable PDA received two cycles of nab-paclitaxel and gemcitabine before surgical resection. FDG-PET and CA19.9 tumour marker levels were used to measure clinical activity. Effects on tumour stroma were determined by endoscopic ultrasound (EUS) elastography. The collagen content and architecture as well as density of cancer-associated fibroblasts (CAFs) were determined in the resected surgical specimen and compared with a group of untreated and treated with conventional chemoradiation therapy controls. A co-clinical study in a mouse model of PDA was conducted to differentiate between the effects of nab-paclitaxel and gemcitabine. RESULTS: A total of 16 patients were enrolled. Treatment resulted in significant antitumour effects with 50% of patients achieving a >75% decrease in circulating CA19.9 tumour marker and a response by FDG-PET. There was also a significant decrement in tumour stiffness as measured by EUS elastography. Seven of 12 patients who completed treatment and were operated had major pathological regressions. Analysis of residual tumours showed a marked disorganised collagen with a very low density of CAF, which was not observed in the untreated or conventionally treated control groups. The preclinical co-clinical study showed that these effects were specific of nab-paclitaxel and not gemcitabine. CONCLUSION: These data suggest that nab-paclitaxel and gemcitabine decreases CAF content inducing a marked alteration in cancer stroma that results in tumour softening. This regimen should be studied in patients with operable PDA.

Characterization of MDGA1, a novel human glycosylphosphatidylinositol-anchored protein localized in lipid rafts.

We report the characterization of the novel human protein MDGA1 encoded by MDGA1 (MAM domain containing glycosylphosphatidylinositol anchor-1) gene, firstly termed as GPIM. MDGA1 has been mapped to 6p21 and it is expressed in human tissues and tumors. The deduced polypeptide consists of 955 amino acids and exhibits structural features found in different types of cell adhesion molecules (CAMs), such as the presence of both immunoglobulin domains and a MAM domain or the capacity to anchor to the cell membrane by a GPI (glycosylphosphatidylinositol) motif. Our results demonstrate that human MDGA1 (hMDGA1) is localized in the membrane of eukaryotic cells. The protein follows the secretion pathway and finally it is retained in the cell membrane by a GPI anchor, susceptible to be cleavaged by phospholipase C (PI-PLC). Moreover, our results reveal that hMDGA1 is localized specifically into membrane microdomains known as lipid rafts. Finally, as other proteins of the secretory pathway, hMDGA1 undergoes other post-translational modification consisting of N-glycosylation.

[Quality of life of cirrhotic patients before and after liver transplantation]. / Calidad de vida de pacientes cirróticos antes y después del trasplante hepático.

In this study we assessed the quality of life of a group of cirrhotic patients who underwent liver transplant using a psychological test to evaluate family relations, work activity, emotional state and social relations. The quantification of hospital dependence and degree of fitness for work, before and after the transplant were also analyzed. 32 patients were included in the study with the diagnosis of hepatic cirrhosis and minimum post-transplant follow-up of 6 months. The average age of the study population was 44.8 +/- 10.5 years; there were 23 males and 9 females, with an average follow-up of 15 months. The psychological test used was the Quality of Life Scale (QLS), which consists of 21 items, each scoring from 1 to 6 points. The questionnaire was completed before the transplant by all the patients, and after the transplant by 32 patients at 6 months, 20 at 12 months and 12 at 24 months. Hospital dependence was evaluated by number of admissions and number of days per admission. Lastly, we compare the rate of unfitness for work before the transplant and at one and two years after the transplant. The QLS test showed a post-transplant improvement in the 4 aspects assessed, specially in the personal aspects (emotions and family) (p < 0.001). Hospital dependence following pre-transplant situation (p < 0.01). Finally, the post-transplant percentage of unfitness for work decreased with time, reaching significant differences 2 years after the liver transplant (p < 0.05).

Life quality of patients undergoing liver transplantation.

The aim of this study was to assess the life quality of a group of patients who had undergone liver transplantation using (1) a psychological test to evaluate family relations, work activity, emotional state and social relationships; (2) the quantification of hospital dependence and degree of fitness for work. Included in the study were 32 patients using the following criteria: diagnosis of hepatic cirrhosis and minimum posttransplant follow-up of 6 months. The average age of the study population was 44.8 +/- 10.5 years; there were 23 males and 9 females, with an average follow-up of 15 months. The psychological test used was the Quality of Life Scale (QLS) which consists of 21 items each scoring from 1 to 6 points. The questionnaire was completed before transplantation by all the patients, and after transplantation by 32 patients at 6 months, 20 at 12 months and 12 at 24 months. Hospital dependence was evaluated by the number of admissions and number of days per admission. Lastly, we compared fitness for work before transplantation and at 1 and 2 years after transplantation. The QLS test showed a post-transplant improvement in the four aspects assessed, particularly in the personal aspects (emotions and family) (P < 0.001). Hospital dependence following liver transplantation decreased significantly compared with the pretransplant situation (P < 0.01). Finally, the post-transplant percentage of unfitness for work decreased with time, reaching a significant differences 2 years after transplantation (P < 0.05).