Do Tissues Fixed in a Non-crosslinking Fixative Require a Dedicated Formalin-free Processor?

We evaluate the consequences of processing alcohol-fixed tissue in a processor previously used for formalin-fixed tissue. Biospecimens fixed in PAXgene Tissue Fixative were cut into three pieces then processed in a flushed tissue processor previously used for formalin-fixed, paraffin-embedded (FFPE) blocks (neutral buffered formalin [NBF]), a formalin-free system (NBF), or left unprocessed. Histomorphology and immunohistochemistry were compared using hematoxylin/eosin staining and antibodies for MLH-1, Ki-67, and CK-7.

Hypoxia-induced autophagy drives colorectal cancer initiation and progression by activating the PRKC/PKC-EZR (ezrin) pathway.

Unlabelled: In solid tumors, cancer stem cells (CSCs) or tumor-initiating cells (TICs) are often found in hypoxic niches. Nevertheless, the influence of hypoxia on TICs is poorly understood. Using previously established, TIC-enrichedpatient-derived colorectal cancer (CRC) cultures, we show that hypoxia increases the self-renewal capacity of TICs while inducing proliferation arrest in their more differentiated counterpart cultures.

Small Nucleolar RNA Score: An Assay to Detect Formalin-Overfixed Tissue.

Although there are millions of formalin-fixed paraffin-embedded (FFPE) tissue blocks potentially available for scientific research, many are of questionable quality, partly due to unknown fixation conditions. We analyzed FFPE tissue biospecimens as part of the NCI Biospecimen Preanalytical Variables (BPV) program to identify microRNA (miRNA) markers for fixation time. miRNA was extracted from kidney and ovary tumor FFPE blocks (19 patients, cold ischemia ≤2 hours) with 6, 12, 24, and 72 hours fixation times, then analyzed using the WaferGen SmartChip platform (miRNA chip with 1036 miRNA targets).

The miR-371∼373 Cluster Represses Colon Cancer Initiation and Metastatic Colonization by Inhibiting the TGFBR2/ID1 Signaling Axis.

The vast majority of colorectal cancer-related deaths can be attributed to metastatic spreading of the disease. Therefore, deciphering molecular mechanisms of metastatic dissemination is a key prerequisite to improve future treatment options. With this aim, we took advantage of different colorectal cancer cell lines and recently established primary cultures enriched in colon cancer stem cells, also known as tumor-initiating cells (TIC), to identify genes and miRNAs with regulatory functions in colorectal cancer progression.

RNA and microRNA Stability in PAXgene-Fixed Paraffin-Embedded Tissue Blocks After Seven Years' Storage.

Objectives: To evaluate the stability of RNA and microRNA (miRNA) in PAXgene-fixed paraffin-embedded tissue blocks after 7 years' storage.

Methods: RNA and miRNA were extracted from PAXgene-fixed paraffin-embedded (PFPE) blocks in 2009 then stored at -80°C. Seven years later, RNA and miRNA were again extracted from the same blocks.

Loss of Myosin Vb in colorectal cancer is a strong prognostic factor for disease recurrence.

Background: Selecting the most beneficial treatment regimens for colorectal cancer (CRC) patients remains challenging due to a lack of prognostic markers. Members of the Myosin family, proteins recognised to have a major role in trafficking and polarisation of cells, have recently been reported to be closely associated with several types of cancer and might thus serve as potential prognostic markers in the context of CRC.

Methods: We used a previously established meta-analysis of publicly available gene expression data to analyse the expression of different members of the Myosin V family, namely MYO5A, 5B, and 5C, in CRC.

A Critical Evaluation of the PAXgene Tissue Fixation System: Morphology, Immunohistochemistry, Molecular Biology, and Proteomics.

Objectives: To evaluate the PAXgene tissue fixation system.

Methods: Clinical biospecimens (n = 46) were divided into PAXgene-fixed paraffin-embedded (PFPE), formalin-fixed paraffin-embedded (FFPE), and fresh-frozen (FF) blocks. PFPE and FFPE sections were compared for histology (H&E staining) and immunohistochemistry (14 antibodies) using tissue microarrays.

Similar α-Synuclein staining in the colon mucosa in patients with Parkinson's disease and controls.

Background: The gut is proposed as a starting point of idiopathic IPD, but the presence of α-synuclein in the IPD colon mucosa is debated.

Objectives: The objective of this study was to evaluate if α-synuclein in the colon mucosa can serve as a biomarker of IPD.

Methods: Immunohistochemistry was used to locate and quantify in a blinded approach α-synuclein in the mucosa from biopsies of the right and left colon in 19 IPD patients and 8 controls.

An Independent Evaluation of the CryoXtract Instruments' CXT350 Frozen Sample Aliquotter Using Tissue and Fecal Biospecimens.

The ability to take targeted multiple cores from a single frozen biospecimen would enable several research projects to be fueled from one biospecimen, a small piece of tissue to be quality-control tested, and for pathologically-discrete areas of a biospecimen (e.g., tumor, stromal, and normal tissue) to be selectively sampled for comparative analyses.

What Do We Learn from Spheroid Culture Systems? Insights from Tumorspheres Derived from Primary Colon Cancer Tissue.

Due to their self-renewal and tumorigenic properties, tumor-initiating cells (TICs) have been hypothesized to be important targets for colorectal cancer (CRC). However the study of TICs is hampered by the fact that the identification and culturing of TICs is still a subject of extensive debate. Floating three-dimensional spheroid cultures (SC) that grow in serum-free medium supplemented with growth factors are supposed to be enriched in TICs.

How Severely Is DNA Quantification Hampered by RNA Co-extraction?

The optional RNase digest that is part of many DNA extraction protocols is often omitted, either because RNase is not provided in the kit or because users do not want to risk contaminating their laboratory. Consequently, co-eluting RNA can become a "contaminant" of unknown magnitude in a DNA extraction. We extracted DNA from liver, lung, kidney, and heart tissues and established that 28-52% of the "DNA" as assessed by spectrophotometry is actually RNA (depending on tissue type).

Platelet activation and aggregation promote lung inflammation and influenza virus pathogenesis.

Rationale: The hallmark of severe influenza virus infection is excessive inflammation of the lungs. Platelets are activated during influenza, but their role in influenza virus pathogenesis and inflammatory responses is unknown.

Objectives: To determine the role of platelets during influenza A virus infections and propose new therapeutics against influenza.