Genetic Profile and Functional Proteomics of Anal Squamous Cell Carcinoma: Proposal for a Molecular Classification.

Anal squamous cell carcinoma is a rare tumor. Chemo-radiotherapy yields a 50% 3-year relapse-free survival rate in advanced anal cancer, so improved predictive markers and therapeutic options are needed. High-throughput proteomics and whole-exome sequencing were performed in 46 paraffin samples from anal squamous cell carcinoma patients. Hierarchical clustering was used to establish groups de novo Then, probabilistic graphical models were used to study the differences between groups of patients at the biological process level. A molecular classification into two groups of patients was established, one group with increased expression of proteins related to adhesion, T lymphocytes and glycolysis; and the other group with increased expression of proteins related to translation and ribosomes. The functional analysis by the probabilistic graphical model showed that these two groups presented differences in metabolism, mitochondria, translation, splicing and adhesion processes. Additionally, these groups showed different frequencies of genetic variants in some genes, such as ATM, SLFN11 and DST Finally, genetic and proteomic characteristics of these groups suggested the use of some possible targeted therapies, such as PARP inhibitors or immunotherapy.

Nondisjunction in favor of a chromosome: the mechanism of rye B chromosome drive during pollen mitosis.

B chromosomes (Bs) are supernumerary components of the genome and do not confer any advantages on the organisms that harbor them. The maintenance of Bs in natural populations is possible by their transmission at higher than Mendelian frequencies. Although drive is the key for understanding B chromosomes, the mechanism is largely unknown. We provide direct insights into the cellular mechanism of B chromosome drive in the male gametophyte of rye (Secale cereale). We found that nondisjunction of Bs is accompanied by centromere activity and is likely caused by extended cohesion of the B sister chromatids. The B centromere originated from an A centromere, which accumulated B-specific repeats and rearrangements. Because of unequal spindle formation at the first pollen mitosis, nondisjoined B chromatids preferentially become located toward the generative pole. The failure to resolve pericentromeric cohesion is under the control of the B-specific nondisjunction control region. Hence, a combination of nondisjunction and unequal spindle formation at first pollen mitosis results in the accumulation of Bs in the generative nucleus and therefore ensures their transmission at a higher than expected rate to the next generation.

Rye B chromosomes influence the dynamics of histone H3 methylation during microgametogenesis.

We have studied the trimethylation dynamics of lysines 4 and 27 of histone H3 in rye with and without B chromosomes (Bs) in root tip mitosis, meiosis, and pollen grain mitosis by immunostaining. In root meristems, H3K4me3 immunolabeling was homogeneous along the chromosome arms of the normal complement (As), with the exception of the pericentromeric and subtelomeric regions which were unlabeled. On the contrary, a signal was observed on the long arm of the B chromosome, in the region where most of the B-specific repeats are located. H3K27me3 immunosignals were observed on the subtelomeric heterochromatic region of the As and the Bs and some interstitial bands of the As. Thus, the terminal region of the Bs showed both signals, whereas the subtelomeric region of the As showed H3K27me3 immunosignals only. During meiosis and first pollen grain mitosis, the immunosignals were observed distributed as in the root tip mitosis in plants with or without Bs. However, we observed remarkable changes in the immunolabeling patterns during the second pollen grain mitosis between 0B and +B plants. In 0B plants, H3K4me3 immunosignals were similarly distributed in the vegetative and generative nuclei. In B-carrying plants, the vegetative nucleus showed a lighter signal than the generative one. In 0B plants, all nuclei of the microgametophyte showed H3K27me3 immunosignals. In B-carrying plants, the generative nucleus and, correspondingly, the second metaphase, anaphase, and sperm nuclei did not show any signal. When the Bs were lost as micronuclei, they did not show any H3K4me3 or H3K27me3 signal. Most remarkably, Bs are able to change the pattern of H3 methylation on K4 and K27 during the second pollen mitosis, resulting in differently labeled sperm nuclei in 0 and +B plants.

Comprehensive Characterization of the Mutational Landscape in Localized Anal Squamous Cell Carcinoma.

Anal squamous cell carcinoma (ASCC) is a rare neoplasm. Chemoradiotherapy is the standard of care, with no therapeutic advances achieved over the past three decades. Thus, a deeper molecular characterization of this disease is still necessary. We analyzed 46 paraffin-embedded tumor samples from patients diagnosed with primary ASCC by exome sequencing. A bioinformatics approach focused in the identification of high-impact genetic variants, which may act as drivers of oncogenesis, was performed. The relation between genetics variants and prognosis was also studied. The list of high-impact genetic variants was unique for each patient. However, the pathways in which these genes are involved are well-known hallmarks of cancer, such as angiogenesis or immune pathways. Additionally, we determined that genetic variants in BRCA2, ZNF750, FAM208B, ZNF599, and ZC3H13 genes are related with poor disease-free survival in ASCC. This may help to stratify the patient's prognosis and open new avenues for potential therapeutic intervention. In conclusion, sequencing of ASCC clinical samples appears an encouraging tool for the molecular portrait of this disease.

Predictive value of angiogenesis-related gene profiling in patients with HER2-negative metastatic breast cancer treated with bevacizumab and weekly paclitaxel.

Bevacizumab plus weekly paclitaxel improves progression-free survival (PFS) in HER2-negative metastatic breast cancer (mBC), but its use has been questioned due to the absence of a predictive biomarker, lack of benefit in overall survival (OS) and increased toxicity. We examined the baseline tumor angiogenic-related gene expression of 60 patients with mBC with the aim of finding a signature that predicts benefit from this drug.Multivariate analysis by Lasso-penalized Cox regression generated two predictive models: one, named G-model, including 11 genes, and the other one, named GC-model, including 13 genes plus 5 clinical covariates. Both models identified patients with improved PFS (HR (Hazard Ratio) 2.57 and 4.04, respectively) and OS (HR 3.29 and 3.43, respectively). The G-model distinguished low and high risk patients in the first 6 months, whereas the GC-model maintained significance over time.

Tumoural Expression of Connective Tissue Growth Factor (CTGF) Impacts on Survival in Patients Diagnosed with Hepatocellular Carcinoma (HCC).

BACKGROUND: Hepatocellular carcinoma (HCC) tends to develop in the liver when there is a high level of background inflammation (cirrhosis). Treatment options are limited and mainly based on systemic therapies such as anti-angiogenic drugs (e.g. sorafenib). Connective tissue growth factor (CTGF) is a matricellular protein involved in inflammation, tumour growth and angiogenesis. The aim of this study is to determine the expression of CTGF and hypoxia inducible factors (HIF) in HCC and to clarify its impact on relapse and survival. MATERIAL AND METHODS: Eligibility criteria for the study consisted of patients with a diagnosis of HCC, formalin-fixed and paraffin-embedded (FFPE) biopsy tissue, as well as relapse and available survival data. A tissue microarray was constructed from ≥ 70% tumoural sections. The expressions of CTGF, HIF1α and HIF2α were analysed by immunohistochemistry. The relationship between expression of CTGF/HIF1α and CTGF/HIF2α were analysed. Univariate and multivariate analyses were performed. RESULTS: Fifty-three patients were screened; 39 patients were eligible for this study. Patients were treated with radical intent. At the end of follow up, 59% patients relapsed (28.2% locally, 10.3% multicentric liver relapse and 7.7% distant metastases). Estimated median disease-free survival (DFS) and overall survival (OS) were 23.4 (95%CI 7.18-39.66) and 38.6 months (95%CI 30.7-46.6), respectively. Expression of CTGF was: negative 23.1%, focal 48.7% and diffuse 23.1%. A non-statistically significant relationship between expression of CTGF and HIF was shown supporting an alternative pathway for CTGF expression in HCC. In multivariate analysis CTGF expression was an independent factor related to OS, with shorter survival in those patients with focal/diffuse CTGF expression (HR 2.46; 95%CI 1.18-5.15). CONCLUSIONS: Our results support that expression of CTGF is an independent factor associated with shorter OS in HCC. Further analysis of CTGF expression in a larger series of HCC patients is required to confirm CTGF as a prognostic biomarker in HCC.