Novus Biologicals Blog

PIM-1: An Important Oncogene in Multiple Cancers

August 29th, 2014

The PIM-1 (proto-oncogene serine/threonine-protein kinase) protein is an epithelial-derived, integral membrane serine protease. This protease forms a complex with the Kunitz-type serine protease inhibitor, HAI-1, and is activated by sphingosine 1-phosphate. PIM-1 cleaves and activates hepatocyte growth factor/scattering factor (HGF) as well as urokinase plasminogen activator (uPA). Such downstream targets implicate this serine protease as an epithelial membrane trigger for a sequential protease cascade. PIM-1 expression is associated with many tumors including breast, colon, prostate, and ovarian. Hematologists at UCLA used the PIM-1 antibody to characterize the physiological effects of ABT-869, a multi-targeted receptor tyrosine kinase inhibitor1. This group found that ABT-869 blocked FMS-like tyrosine kinase 3-internal tandem duplication (FLT3) phosphorylation, induced apoptosis, decreased proliferation, reduced tumor formation, and increased survival in their acute myeloid leukemia (AML) models.

Immunohistochemistry-Paraffin: PIM1 Antibody

Immunohistochemistry-Paraffin: PIM1 Antibody

Prendergast’s group also employed the PIM-1 antibody to study centromere chromatin with respect to pre-mitosis assembly and inheritance of a histone fold complex2. Their data led them to propose that the different centromere CENP proteins are specifically utilized for centromere and kinetochore functions. Studies on innate immunity relied upon ELISA assays with the PIM-1 antibody identified five novel autoantibodies that could contribute to type I interferon production in plasmacytoid dendritic cells in a nucleic acid-independent fashion3. These newly found antibodies appear to function in a variety of cell processes and should be further studied.

Novus Biologicals offers PIM1 reagents for your research needs including:

PMIDs

  1. 17209055
  2. 21695110
  3. 23973875

APE1: A Multifunctional Protein

August 27th, 2014

AP-endonuclease (APE1/Ref-1) is an essential multifunctional protein involved in the repair of oxidative DNA damage as well as in transcriptional regulation in tumor cells. It functions as an apurinic/apyrimidinic (AP) endodeoxyribonuclease in the DNA base excision repair (BER) pathway of DNA lesions, and may also play a role in the epigenetic regulation of gene expression and the protection from granzymes-mediated cellular repair leading to cell death. APE1 is involved in calcium-dependent down-regulation of parathyroid hormone (PTH) expression by binding to negative calcium response elements (nCaREs).

Melphalan resistance has been considered one of the major obstacles to improve outcomes in multiple myeloma (MM) therapy. A study using Novus’ APE1 antibody, NB100-116, has shown that the acetylation modification of APE1 is involved in melphalan resistance of MM cells and has also shed light on future therapeutic strategies targeting specific APE1 functions by small molecule inhibitors. (1) Another study using the same APE1 antibody describes a unique role of Ape1 in telomere protection, providing a direct link between base excision DNA repair activities and telomere metabolism. (2)

Immunocytochemistry/Immunofluorescence: APE1 Antibody

Immunocytochemistry/Immunofluorescence: APE1 Antibody

Resistance to radiotherapy is a key limitation for the treatment of human hepatocellular carcinoma (HCC). A study using Novus’ APE1 antibody, NB100-116, has shown that downregulation of APE1 could enhance sensitivity of human HCC cells to radiotherapy in vitro and in vivo. (3) Radiotherapy is an important treatment for the patients with advanced pancreatic cancer. Emerging studies determined apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) might associate with the resistance of human pancreatic cancer cells to radiotherapy. Down-regulation of apurinic/apyrimidinic endonuclease 1/redox factor-1 enhances the sensitivity of human pancreatic cancer cells to radiotherapy in vitro. (4) Abdel-Fatah’s group used Novus’ APE1 antibody, NB100-101 antibody to show that low APE1 expression may have prognostic and predictive significance in ER-positive breast cancers. (5)

  1. PMID: 24400589
  2. PMID: 24127576
  3. PMID: 23418439
  4. PMID: 23268706
  5. PMID: 24381055

Novus Biologicals offers APE1 reagents for your research needs including:

FANCD2: A big component of the DNA repair crew

August 25th, 2014

The genetic disorder known as Fanconi anemia (FANC) is a heterogeneous, autosomal-recessive cancer susceptibility condition characterized by a wide array of symptoms. These include congenital malformations, progressive bone marrow failure, DNA-damage hypersensitivity, and genome instability. The protein FANCD2 is a subunit of the protein complex involved in cellular resistance to DNA cross-linking and DNA synthesis arrest triggered by ionizing radiation (IR). The FANCD2 antibody was used in immunoblotting and immunoprecipitation experiments to better understand how processes such as oxidative stress and damage trigger the formation of a multimeric FANC complex within the nucleus1.

Western Blot: FANCD2 Antibody

Western Blot: FANCD2 Antibody

Studies from Harvard focused on DNA damage response pathway defects in breast cancer employed the FANCD2 antibody2. This group established and validated a new ex vivo foci biomarker assay approach that could detect both pre-existing and functionally important FA/BRCA pathway defects. This assay would allow customization of future cancer therapies to individual tumor DNA repair profiles. The FANCD2 antibody was also used by Danish researchers in their provocative chromatin spatial co-localization studies aimed at surveying genome regulators (repair factors such as Rad and BRCA1) and their accumulation within the chromatin microenvironment3. Kim et al published in Nature Genetics their findings using the FANCD2 antibody to analyze SLX4 mutations in FANC where they found that biallelic mutations define a new subtype of FANC, known as Fanconi anemia-P4. Recent studies from Nalepa’s group were able to systematically evaluate the role of FANC proteins in spindle assembly checkpoints5. With the FANCD2 antibody, they were able to demonstrate an essential role for the FA pathway in mitosis and high-fidelity chromosome segregation.

PMIDs

  1. 15138265
  2. 19671671
  3. 16618811
  4. 21240275
  5. 23934222

A Double-Edged Sword: GDF15

August 22nd, 2014

Bone morphogenetic proteins such as GDF15 belong to the transforming growth factor-beta (TGFB) family that directs tissue differentiation and maintenance. GDF15 appears to be involved in a variety of physiological processes such as pregnancy, injury and inflammation, and apoptosis. Evidence suggests GDF15 is a marker for metastasis. A Swiss group profiled expression of GDF15 via RT-PCR and immunoblotting with the GDF15 antibody in mouse and human glioma cell lines to better correlate tumor grade with proliferative capability and immunogenicity1. Their data clearly showed that endogenous levels of GDF15 cause proliferation and immune escape of glioma cells. Tabrizi et al performed similar profiling studies with the GDF15 antibody in primary ovarian mucinous carcinomas of the intestine2. Based on their studies, they suggest that current and updated diagnostic criteria and standards for borderline cases are sufficient.

Immunohistochemistry-Paraffin: GDF15 Antibody

Immunohistochemistry-Paraffin: GDF15 Antibody

Immunohistochemistry and microarrays done in colorectal cancer (CRC) patient samples with the GDF15 antibody appear to validate GDF15 as a negative prognostic marker for both recurrence risk and overall survival3. Preliminary studies out of Suesskind’s group in Germany suggest that GDF15 may also serve as a novel serum marker for uveal melanoma metastases4. This group used GDF15 antibody in their ELISA and immunohistochemistry experiments, and believe GDF15 may predict early metastases in a disease where half of patients develop metastases during disease progression. Interestingly, GDF15 may also have a role in idiopathic pulmonary arterial hypertension (IPAH), as the GDF15 antibody allowed Nickel’s group to validate increased GDF15 expression within vascular endothelial cells in diseased lungs5.

Novus Biologicals offers GDF15 reagents for your research needs including:

PMIDs

  1. 20534737
  2. 20173494
  3. 21468045
  4. 21881845
  5. 21548946

PCSK9: To neuron or not to neuron

August 20th, 2014

PCSK9 (Proprotein convertase subtilisin/kexin type 9) is a member of the proteinase K subfamily of the secretory subtilase family. It is first produced as a soluble zymogen that then undergoes an autocatalytic processing within the endoplasmic reticulum (ER). PCSK9 functions in cholesterol homeostasis as well as cortical neuron differentiation. Mutations in this gene are associated with a third form of autosomal dominant familial hypercholesterolemia (HCHOLA3). Blesa’s group used the PCSK9 antibody to study the prevalence of PCSK9 mutations in autosomal dominant hypercholesterolemia (ADH) within a particular Spanish subpopulation1. There were unable to detect any of the previously described mutations they were looking for within this cohort, but identified a novel mutation responsible for increasing PCSK9 transcription. Dube et al employed the PCSK9 antibody in their gestational diabetes mellitus (GDM) investigations into correlations between pre-pregnancy body mass indices (BMI) and cholesterol transport2. A group of Australian researchers developed a sandwich ELISA with the PCSK9 antibody to allow them to assess LDL and total cholesterol levels in diabetic patients treated with the cholesterol-lowering drug fenofibrate3.

Western Blot: PCSK9 Antibody

Western Blot: PCSK9 Antibody

The PCSK9 antibody was also integrated into ChIP and immunoblot experiments by Diebold’s group, who studied the correlations between NADPH oxidase subunit (NOX4) and hypoxia-induced factor (HIF-1) under both hypoxic and non-hypoxic conditions4. A Swiss group used the PCSK9 antibody to demonstrate that the coordinated regulation of genes implicated in hepatic cholesterol homeostasis (SREBP-1, Niemann-Pick C1 like 1 protein) can complement statin treatment5. Their simultaneous analysis of many genes allowed them to assess the efficacy of therapeutics like rosuvastatin.

Novus Biologicals offers PCSK9 reagents for your research needs including:

PMIDs

  1. 18559913
  2. 23221398
  3. 18436719
  4. 20427574
  5. 20461026

PINK1 and its role in Parkinson’s disease

August 19th, 2014

PINK1 (PTEN induced putative kinase 1) is a mitochondrial serine/threonine kinase which maintains mitochondrial function/integrity, provides protection against mitochondrial dysfunction during cellular stress, potentially by phosphorylating mitochondrial proteins, and is involved in the clearance of damaged mitochondria via selective autophagy (mitophagy). PINK1 and its substrates have been found in the cytosol as well as in different sub-mitochondrial compartments.  According to recent reports, PINK1 may be targeted to OMM (outer mitochondrial membrane) with its kinase domain facing the cytosol, providing a possible explanation for the observed physical interaction with the cytosolic E3 ubiquitin ligase Parkin. PINK1 has been linked to autosomal recessive early onset Parkinson’s disease, Alzheimer’s disease, dementia, multiple sclerosis, schizophrenia, neuronitis, myeloma ect.

Parkinson’s disease (PD) is a progressive and irreversible neurodegenerative disorder coupled to selective degeneration of dopamine-producing neurons in the substantia nigra. Mutations in PINK1 cause autosomal recessive forms of early-onset PD and PINK1 stimulates Omi/HtrA2/PARK13 protease activity when both proteins act as neuroprotective components in the same stress pathway. Although PARK13-mediated protective mechanisms are at least in part regulated by PINK1, little is known concerning how these two proteins are regulated in different subcellular compartments. Recent study has indicated a correlative relationship between the two proteins. Moreover, they showed that PARK13 and PINK1 protein levels accumulate in response to H2 O2 and L-DOPA treatments in a subcellular fashion and that both proteins show relocation to the cytoskeleton in response to H2 O2 . This study shows that PARK13 and PINK1 are subcellular-specific but dynamic proteins with a reciprocal molecular relationship providing new insight into the complexity of PD. (1)

Immunocytochemistry/Immunofluorescence: PINK1 Antibody

Immunocytochemistry/Immunofluorescence: PINK1 Antibody

The mitochondrial kinase PINK1 and the ubiquitin ligase Parkin participate in quality control after CCCP- or ROS-induced mitochondrial damage, and their dysfunction is associated with the development and progression of Parkinson’s disease. Furthermore, PINK1 expression is also induced by starvation indicating an additional role for PINK1 in stress response. Therefore, the effects of PINK1 deficiency on the autophagy-lysosomal pathway during stress were investigated. PINK1-mediated reduction of autophagic key factors during stress resulted in increased cell death, thus defining an additional pathway that could contribute to the progression of Parkinson’s disease in patients with PINK1 mutations. (2)

Another study has shown that mitochondrial impairment increases FL-PINK1 levels by calcium-dependent gene expression suggesting a role for PINK1 in mitophagy that is downstream of ubiquitination of mitochondrial substrates. The sensitivity to intracellular calcium levels supports the hypothesis that PINK1 may also play a role in cellular calcium homeostasis and neuroprotection. (3)

Novus Biologicals offers PINK1 reagents for your research needs including:

PMIDs

  1. PMID: 24798695
  2. PMID: 24751806
  3. PMID: 24184327

NUT – A Protein Coding Gene

August 15th, 2014

The NUT gene is found on chromosome 15q14 and encodes for the NUT protein which is a key component of the RNA polymerase II Mediator complex. This multi-subunit assembly is required for all RNA pol II-dependent transcriptional activation, coordinating both nuclear and mitochondrial gene transcription. The complex also includes pol II, and transcription factors TFIIA-F. It serves as a central scaffold within the pre-initiation complex (PIC) responsible for converting biological stimuli (in the form of transcription factors) into gene expression responses. A good review of Mediator function and influencing factors can be found in Poss et al1.

Immunohistochemistry-Paraffin: NUT Antibody

Immunohistochemistry-Paraffin: NUT Antibody

Additionally, the poorly understood disease known as NUT midline carcinoma (NMC) is a rare and aggressive squamous carcinoma involving chromosomal rearrangements that generate a NUT protein fused with either one of  the bromodomain-containing proteins BRD4 and BRD32. A research group from Sweden believes that the Mediator complex may have also have a different role in telomeric silencing and cell senescence and lifespan determination3. They found that Mediator directly associates with telomeric heterochromatin between active and inactive content.

Novus Biologicals offers NUT reagents for your research needs including:

PMIDs

  1. 24088064
  2. 22017582
  3. 21482672

Neurofibromatosis Infographic

August 14th, 2014

Neurofibromatosis (NF) is a genetic disorder caused by mutations in the NF1, NF2 or SMARCB1 genes which lead to tumor growth on nerves throughout the body. Although the tumors are usually benign, they still require chemotherapy to shrink and may become cancerous. Surgery is often attempted as treatment, however tumor placement on sensitive areas such as spinal cord and optic nerve make this option more difficult.

Neurofibromatosis Infographic

Resources

  1. CTF.org 
  2. Mayo Clinic 
  3. NIH 
  4. Mayo Clinic 
  5. Cancer.net 
  6. Britannica.com
  7. HopkinsMedicine.org 
  8. Nfauk.org

NEUROFIBROMATOSIS Infographic Download the PDF of the Neurofibromatosis Infographic

By: Lisa Ikariyama & Kim Mesman

NALP4 – Mediator of Programmed Cell Death

August 13th, 2014

The NALP family consists of cytoplasmic proteins within the larger CATERPILLER protein family. There exist in short forms (such as NALP4) and long forms (NALP1). NALP proteins include the apoptosis regulator apoptotic protease activating factor 1 (APAF1) and mammalian NOD-LRR proteins, and are thought to play a role in the inflammation and reproduction processes. They play a key role in the formation of large signal-induced proinflammatory multiprotein complexes termed “inflammasomes”, as published in a Nature Molecular Cell Biology 2003 review by Tschopp, more recently reviewed by Boaru1,2. NALP4 is also involved in modulating NF-kB activity.

Immunohistochemistry: NALP4 Antibody

Immunohistochemistry: NALP4 Antibody

Additionally, a comprehensive study by Assou’s group focused on early embryonic development found that many NALP family genes (NALP4, NALP5, NALP9, NALP11 and NALP13) are key biomarkers of trophectoderm (TE) cells and the steroidogenesis process3. A Japanese research group used the NALP4 antibody to demonstrate in interaction between several NALP family members and the autophagy regulator Beclin14. Their data provides novel evidence that NALP4, as well as other related family proteins, play a fundamental role in autophagosome biogenesis and maturation by complexing with regulatory modulators such as Beclin1 and the class C protein-sorting aggregated complex.

Novus Biologicals offers NALP4 reagents for your research needs including:

PMIDs

  1. 12563287
  2. 23192004
  3. 22761758
  4. 21209283