PHLDA1 is a crucial negative regulator and effector of Aurora A kinase in breast cancer

Johnson, Emmanuel O.; Chang, Kuei Hua; Pablo, Yolanda de; Ghosh, Soumitra; Mehta, Rutika; Badve, Sunil; Shah, Kavita

doi:10.1242/jcs.084970

Cited by 70 publications

(107 citation statements)

References 51 publications

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“…also, in the most of the analyzed neuroblastoma cell lines, i.e., IMR-32, SK-N-SH, Kelly, CHP-134, HTLA230 such inverse correlations can be stated. Hence, the above findings allow us to hypothesize that in IMR-32 cells Aurora A and PHLDA1 are proteins that might negatively regulate each other, as reported previously by Johnson et al for the MDA-MB-231 breast cancer cells (10). Therefore, further experiments should be performed to show a direct physical interactions of the proteins.…”

Section: Discussionsupporting

confidence: 71%

“…In MDA-MB-231 breast cancer cells, Aurora A is a partner of PHLDA1 and more importantly both proteins are engaged in mutual regulation (10). Additionally, among several substrates, Aurora A complexes MYCN and stabilizes the transcription factor by preventing it from Fbxw7-driven proteasomal degradation (11).…”

Section: Characterization Of Expression Of Selected Genes Involved Inmentioning

confidence: 99%

“…In a yeast two hybrid system three proteins involved in regulation of translation, including RPL14, were found to bind PHLDA1 (9). In 2011, Johnson et al have shown that the mitotic kinase Aurora A, an oncoprotein overexpressed in the majority of breast cancer tumors, and PHLDA1 associate regulating each other in MDA-MB-231 breast cancer cells (10). In neuroblastoma, the most common extra-cranial tumor of childhood, Aurora A (encoded by AURKA) and MYCN are partners in driving the malignancy and negative prognostic factors (11,12).…”

Section: Introductionmentioning

confidence: 99%

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Downregulation of the PHLDA1 gene in IMR-32 neuroblastoma cells increases levels of Aurora A, TRKB and affects proteins involved in apoptosis and autophagy pathways

Durbas

Horwacik

Boratyn

et al. 2016

International Journal of Oncology

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Abstract.We have recently shown that mRNA and protein of PHLDA1 (pleckstrin-homology-like domain family A, member 1) were by far the most upregulated molecules upon treatment of IMR-32 cells with the anti-GD2 ganglioside monoclonal antibody 14G2a. Hence, we decided to study functions of PHLDA1 using human neuroblastoma IMR-32 cells as a model. Here, we show that constitutive expression of mRNA and protein of the PHLDA1 gene in IMR-32 cells was inversely correlated with transcript of the AURKA gene and Aurora A oncoprotein. Next, we silenced PHLDA1 expression in IMR-32 cells using an shRNA interference method. We report that IMR-32 cells with stable downregulation of PHLDA1 showed enhanced cellular ATP levels and an increase in mitochondrial membrane potential, as compared to control and non-transduced cells. We demonstrated that downregulation of PHLDA1 leads to a significant increase in expression of Aurora A and TRKB that are markers of poor prognosis in neuroblastoma. Also, we measured an increase in Aurora A and Akt kinases phosphorylation in the cells. Most importantly, PHLDA1-silenced cells were less susceptible to apoptosis than control cells, as shown by the lower expression of cleaved caspase-3 and PARP as well as a decreased activity of caspase-3 and -7. Our study negatively correlates expression of PHLDA1 and Aurora A in IMR-32 cells and sheds new light on functions of PHLDA1 in the neuroblastoma tumor cells, suggesting its role as a pro-apoptotic protein. Additionally, our results show possible links of the protein to regulation of features of mitochondria and formation of autophagosomes. IntroductionPHLDA1 was identified as a gene involved in Fas (CD95) expression and apoptosis induced after an anti-TCR antibody binding to mouse T cell hybridoma cells (1). In humans the gene is located on the long arm of the chromosome 12 [12q15 (2)] and encodes a 401 amino acid (aa) protein (45 kDa) named pleckstrin-homology-like domain family A, member 1 (PHLDA1, synonyms include: DT1P1B11, PHRIP, 'prolinehistidine rich protein', TDAG51, based on www.genecards. org).Several research groups have aimed to characterize involvement of PHLDA1 in biology of cancer cells, including its function in apoptosis. Thus, Neef et al measured levels of mRNA of PHLDA1 in three sets of cell lines, derived from paired samples of primary and metastatic melanoma tumors, and reported that PHLDA1 was downregulated in the latter. PHLDA1 was detected by the authors in benign melanocytic nevi, and its level was shown to decrease with progression of malignant melanomas. Also, constitutive expression of the PHLDA1 protein in a melanoma cell line Mel Rif has led to cell growth reduction along with an increase in basal apoptosis and sensitivity to doxorubicin and camptothecin (3). In 2006, Hayashida et al showed that PHLDA1 is a heat shock inducible gene regulated by HSF1 and when overexpressed in HeLa cells has pro-apoptotic functions (4). In yet another report, Nagai et al have reported that downregulation of PHLDA1 is a strong predictor of ...

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Section: Discussionsupporting

confidence: 71%

Section: Characterization Of Expression Of Selected Genes Involved Inmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Downregulation of the PHLDA1 gene in IMR-32 neuroblastoma cells increases levels of Aurora A, TRKB and affects proteins involved in apoptosis and autophagy pathways

Durbas

Horwacik

Boratyn

et al. 2016

International Journal of Oncology

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“…We recently identified PHLDA1 as a direct target of Aurora A in breast cancer cells using a modified chemical genetic approach (Johnson et al, 2011). In the present study, LIMK2 was followed up as a direct target of Aurora A, which revealed a new mechanism by which Aurora A overexpression might not only promote breast malignancy, but other types of cancer as well.…”

Section: Introductionmentioning

confidence: 51%

LIMK2 is a crucial regulator and effector of Aurora-A-kinase-mediated malignancy

Johnson

Chang

Ghosh

et al. 2012

Journal of Cell Science

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SummaryAurora A is overexpressed in majority of breast carcinomas. With the exception of BRCA1 and PHLDA1, no oncogenic Aurora A substrates are known in breast cancer. In this study, a chemical genetic approach was used to identify malignant targets of Aurora A, which revealed LIMK2 as a novel Aurora A substrate. Aurora A regulates LIMK2 kinase activity, subcellular localization and protein levels by direct phosphorylation at S283, T494 and T505. In response, LIMK2 also positively regulates the level of Aurora A, thereby engaging in a positive-feedback loop, promoting Aurora-A-mediated oncogenic pathways. Most importantly, LIMK2 ablation fully abrogates Aurora-A-mediated tumorigenesis in nude mice, suggesting that LIMK2 is a key oncogenic effector of Aurora A. Furthermore, LIMK2 ablation acts synergistically with inhibition of Aurora A in promoting cell death. Finally, Aurora-A-mediated upregulation of LIMK2 appears to be a common mechanism in many cancers. LIMK2 inhibition or ablation is therefore an alternative approach for modulating Aurora A deregulation in cancer.

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“…The complementary substituent on ATP is created by attaching bulky groups at the N-6 position of ATP. These ATP analogs are not accepted by wild-type kinases due to steric effects, permitting unbiased identification of direct substrates of the engineered kinase in a global environment (Shah and Vincent, 2005;Kim and Shah, 2007;Johnson et al, 2011;Johnson et al, 2012). Importantly, the sensitized allele created by this mutation has identical substrate specificity to the wild-type kinase.…”

Section: Foxo3a Is a Direct Substrate Of Cdk5mentioning

confidence: 99%

Cdk5–Foxo3 axis: initially neuroprotective, eventually neurodegenerative in Alzheimer's disease models

Shi

Viccaro

Lee

et al. 2016

Journal of Cell Science

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Deregulated Cdk5 causes neurotoxic amyloid beta peptide (Aβ) processing and cell death, two hallmarks of Alzheimer's disease, through the Foxo3 transcriptional factor in hippocampal cells, primary neurons and an Alzheimer's disease mouse model. Using an innovative chemical genetic screen, we identified Foxo3 as a direct substrate of Cdk5 in brain lysates. Cdk5 directly phosphorylates Foxo3, which increased its levels and nuclear translocation. Nuclear Foxo3 initially rescued cells from ensuing oxidative stress by upregulating MnSOD (also known as SOD2). However, following prolonged exposure, Foxo3 upregulated Bim (also known as BCL2L11) and FasL (also known as FASLG) causing cell death. Active Foxo3 also increased Aβ(1-42) levels in a phosphorylationdependent manner. These events were completely inhibited either by expressing phosphorylation-resistant Foxo3 or by depleting Cdk5 or Foxo3, highlighting a key role for Cdk5 in regulating Foxo3. These results were confirmed in an Alzheimer's disease mouse model, which exhibited increased levels and nuclear localization of Foxo3 in hippocampal neurons, which preceded neurodegeneration and Aβ plaque formation, indicating this phenomenon is an early event in Alzheimer's disease pathogenesis. Collectively, these results show that Cdk5-mediated phospho-regulation of Foxo3 can activate several genes that promote neuronal death and aberrant Aβ processing, thereby contributing to the progression of neurodegenerative pathologies.

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PHLDA1 is a crucial negative regulator and effector of Aurora A kinase in breast cancer

Cited by 70 publications

References 51 publications

Downregulation of the PHLDA1 gene in IMR-32 neuroblastoma cells increases levels of Aurora A, TRKB and affects proteins involved in apoptosis and autophagy pathways

Downregulation of the PHLDA1 gene in IMR-32 neuroblastoma cells increases levels of Aurora A, TRKB and affects proteins involved in apoptosis and autophagy pathways

LIMK2 is a crucial regulator and effector of Aurora-A-kinase-mediated malignancy

Cdk5–Foxo3 axis: initially neuroprotective, eventually neurodegenerative in Alzheimer's disease models

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