View source for Midkine

{{other uses|Mk (disambiguation)|MDK (disambiguation)}}
{{Infobox_gene}}

'''Midkine''' (MK or MDK) also known as '''[[neurite]] growth-promoting factor 2''' (NEGF2) is a [[protein]] that in humans is encoded by the ''MDK'' [[gene]].<ref name="pmid8406506">{{cite journal |vauthors=Kaname T, Kuwano A, Murano I, Uehara K, Muramatsu T, Kajii T | title = Midkine gene (MDK), a gene for prenatal differentiation and neuroregulation, maps to band 11p11.2 by fluorescence in situ hybridization | journal = Genomics | volume = 17 | issue = 2 | pages = 514–5 |date=August 1993 | pmid = 8406506 | doi = 10.1006/geno.1993.1359 | url =  }}</ref>

Midkine is a basic [[heparin]]-binding [[growth factor]] of low molecular weight, and forms a family with [[pleiotrophin]] (NEGF1, 46% homologous with MK). It is a nonglycosylated protein, composed of two domains held by [[disulfide bond|disulfide bridges]]. It is a developmentally important [[retinoic acid]]-responsive gene product strongly induced during ''mid''-gestation, hence the name ''mid''kine. Restricted mainly to certain tissues in the normal adult, it is strongly induced during [[oncogenesis]], inflammation and tissue repair.

MK is [[pleiotropic]], capable of exerting activities such as [[cell growth|cell proliferation]], [[cell migration]], [[angiogenesis]] and [[fibrinolysis]]. A molecular complex containing receptor-type tyrosine phosphatase zeta ([[PTPRZ1|PTPζ]]), low density lipoprotein receptor-related protein ([[LRP1]]), anaplastic leukemia kinase ([[anaplastic lymphoma kinase|ALK]]) and [[syndecans]] is considered to be its receptor.<ref>{{cite journal |author=Muramatsu Takashi |title=Midkine and pleiotrophin: two related proteins involved in development, survival, inflammation and tumorigenesis |journal=J. Biochem. |volume=132 |issue=3 |pages=359–71 |date=1 September 2002|url=http://jb.oxfordjournals.org/cgi/content/abstract/132/3/359 |pmid=12204104 |doi=10.1093/oxfordjournals.jbchem.a003231}}</ref>

== Role in cancer ==

MK appears to enhance the angiogenic and proliferative activities of cancer cells.<ref name="pmid11048798">{{cite journal |vauthors=Kato M, Maeta H, Kato S, Shinozawa T, Terada T | title = Immunohistochemical and in situ hybridization analyses of midkine expression in thyroid papillary carcinoma | journal = Mod. Pathol. | volume = 13 | issue = 10 | pages = 1060–5 |date=October 2000 | pmid = 11048798 | doi = 10.1038/modpathol.3880195 | url =  }}</ref> The expression of MK (mRNA and protein expression) has been found to be elevated in multiple cancer types, such as neuroblastoma, glioblastoma, Wilms’ tumors, thyroid papillary carcinomas,<ref name="pmid11048798"/> colorectal, liver, ovary, bladder, breast, lung, esophageal, stomach, and prostate cancers.<ref name="pmid10952771">{{cite journal |vauthors=Ikematsu S, Yano A, Aridome K, Kikuchi M, Kumai H, Nagano H, Okamoto K, Oda M, Sakuma S, Aikou T, Muramatsu H, Kadomatsu K, Muramatsu T | title = Serum midkine levels are increased in patients with various types of carcinomas | journal = Br. J. Cancer | volume = 83 | issue = 6 | pages = 701–6 |date=September 2000 | pmid = 10952771 | doi = 10.1054/bjoc.2000.1339 | url = | pmc = 2363529 }}</ref> Serum MK in normal individuals is usually less than 0.5-0.6&nbsp;ng/ml, whereas patients with these malignancies have much higher levels than this. In some cases, these elevated levels of MK also indicate a poorer prognosis of the disease, such as in neuroblastoma, gliablastoma, and bladder carcinomas.<ref name="pmid12771916">{{cite journal |vauthors=Ikematsu S, Nakagawara A, Nakamura Y, Sakuma S, Wakai K, Muramatsu T, Kadomatsu K | title = Correlation of elevated level of blood midkine with poor prognostic factors of human neuroblastomas | journal = Br. J. Cancer | volume = 88 | issue = 10 | pages = 1522–6 |date=May 2003 | pmid = 12771916 | doi = 10.1038/sj.bjc.6600938 | url = | pmc = 2377118 }}</ref>  In neuroblastoma, for example, the levels of MK are elevated about three times the level in Stage 4 of the cancer (one of the final stages) than they are in Stage 1.<ref name="pmid12771916"/>

In neuroblastoma, MK has been found to be over expressed in the cancer cells that are resistant to chemotherapeutic drugs.<ref name="pmid15897897">{{cite journal |vauthors=Mirkin BL, Clark S, Zheng X, Chu F, White BD, Greene M, Rebbaa A | title = Identification of midkine as a mediator for intercellular transfer of drug resistance | journal = Oncogene | volume = 24 | issue = 31 | pages = 4965–74 |date=July 2005 | pmid = 15897897 | doi = 10.1038/sj.onc.1208671 | url =  }}</ref><ref name="pmid11474132">{{cite journal |vauthors=Rebbaa A, Chou PM, Mirkin BL | title = Factors secreted by human neuroblastoma mediated doxorubicin resistance by activating STAT3 and inhibiting apoptosis | journal = Mol. Med. | volume = 7 | issue = 6 | pages = 393–400 |date=June 2001 | pmid = 11474132 | pmc = 1950050 | doi = | url =  }}</ref> The resistance to chemotherapy seems to be reversible by administering chemo-resensitization drugs, such as verapamil,<ref name="pmid8999846">{{cite journal |vauthors=Lavie Y, Cao H, Volner A, Lucci A, Han TY, Geffen V, Giuliano AE, Cabot MC | title = Agents that reverse multidrug resistance, tamoxifen, verapamil, and cyclosporin A, block glycosphingolipid metabolism by inhibiting ceramide glycosylation in human cancer cells | journal = J. Biol. Chem. | volume = 272 | issue = 3 | pages = 1682–7 |date=January 1997 | pmid = 8999846 | doi = 10.1074/jbc.272.3.1682| url =  }}</ref> which acts not via MK alteration, but by inhibiting the P-glycoprotein pump that exports cytotoxins out of cells.<ref name="pmid2569930">{{cite journal |vauthors=Yusa K, Tsuruo T | title = Reversal mechanism of multidrug resistance by verapamil: direct binding of verapamil to P-glycoprotein on specific sites and transport of verapamil outward across the plasma membrane of K562/ADM cells | journal = Cancer Res. | volume = 49 | issue = 18 | pages = 5002–6 |date=September 1989 | pmid = 2569930 | doi = | url =  }}</ref> Since chemotherapeutic drugs are cytotoxic, the drugs administered are also exported by this pump, rendering the chemotherapy ineffective.<ref name="pmid2569930"/> It has been found that when the neuroblastoma cells that are resistant to chemotherapy are grown in co-culture with the wild type (WT), or chemotherapy-sensitive cells, the resistance to chemotherapy is conferred to the wild type cells, and thus no cell death or senescence occurs in either cell type,<ref name="pmid15897897"/> despite the chemotherapeutic treatment. MK has been identified as one of the factors that “transfers” this chemoresistance from the resistant cells to the WT cells.<ref name="pmid11474132"/>

MK is a secreted protein, and is therefore found in the microenvironment (media) of the resistant neuroblastoma cells.<ref name="pmid11474132"/> Following co-culture experiments and the determination that MK was one of the factors that was conferring chemo-resistance to the wild, non-resistant cell type,<ref name="pmid11474132"/> the gene for MK was transfected into WT cells to determine if MK was overexpressed in the WT cells themselves, would the cells become resistant to chemotherapy independent of resistant cell influence. The tests further confirmed that MK specifically increased chemotherapeutic resistance in the transfected WT-MK cells versus regular WT cells, confirming the specific chemoresistant properties of MK.<ref name="pmid15897897"/>

In addition, the mechanism for such anti-apoptotic (anti-cell death) activity was studied, specifically using the chemotherapeutic Doxorubicin (Adriamycin) on osteosarcoma (Saos2) cells.<ref name="pmid15897897"/> Doxorubicin works by putting rampant cancer cells into a senescent state. MK, in WT-MK transfected cells versus WT cells, seemed to activate PKB (Akt), mTOR, and Bad protein, while it inactivated caspase-3.<ref name="pmid15897897"/> PKB, mTOR, and Bad are all elements associated with the cell cycle survival pathway, whereas caspase-3 is important in the apoptotic pathway (cell death).<ref name="pmid15897897"/> This indicates that MK caused the cells to initiate the survival pathway (via PKB, mTOR, and Bad activation) and inhibit the senescent or apoptotic pathway (via inhibiting caspase-3)<ref name="pmid15897897"/> encouraging the chemoresistance seen in resistant cells and in the co-culture experiments. The activation and inhibition of these particular factors clearly is maintaining the immortal quality inherent in cancer cells and specifically in the resistant cell types. Stat-3, however, which is another survival pathway factor, does not appear to have any change in activation between the wild type cells and the MK-transfected WT cells,<ref name="pmid15897897"/> as was initially believed from a previous study.<ref name="pmid11474132"/>

MK may potentially be indirectly targeted as a cancer treatment as a result of its cancerous proliferation properties.<ref name="pmid17172400">{{cite journal |vauthors=Ireson CR, Kelland LR | title = Discovery and development of anticancer aptamers | journal = Mol. Cancer Ther. | volume = 5 | issue = 12 | pages = 2957–62 |date=December 2006 | pmid = 17172400 | doi = 10.1158/1535-7163.MCT-06-0172 | url =  }}</ref> Drugs by the name of anti-cancer aptamers have been created to inhibit to proteins involved in MK’s cancer cell “activation”. Specifically, the extra-cellular matrix (ECM) protein nucleolin has been targeted with an aptamer that would bind nucleolin and prevent MK from being transported into cancerous cell nuclei, preventing the protein from enhancing the cancerous properties of the cell.<ref name="pmid17172400"/> Miyakawa ''et al.'' have successfully established the method to prepare the MDK specific RNA aptamers<ref>[http://www.freepatentsonline.com/8080649.pdf Miyakawa S, Fujiwara M, Nakamura Y, Matsui T, and Sakuma S. Aptamer against midkine and use thereof. United States Patent 8080649, 2011]</ref> by the use of the recombinant midkine<ref name="pmid12597883">{{cite journal  |vauthors=Murasugi A, Tohma-Aiba Y |title=Production of native recombinant human midkine in the yeast, ''Pichia pastoris'' |journal=Protein Expr. Purif. |volume=27 |issue= 2 |pages= 244–52 |year= 2003 |pmid= 12597883 |doi=10.1016/S1046-5928(02)00587-9 }}</ref> and [[pleiotrophin]].<ref name="pmid14586125">{{cite journal  |vauthors=Murasugi A, Kido I, Kumai H, Asami Y |title=Efficient production of recombinant human pleio-trophin in yeast, ''Pichia pastoris''. |journal=Biosci. Biotechnol. Biochem. |volume=67 |issue= 10 |pages= 2288–90 |year= 2003 |pmid= 14586125 |doi=10.1271/bbb.67.2288 }}</ref>

Mdk is also a tumor antigen able to induce CD8 and CD4 T cell responses (Kerzerho and al. 2010 Journal of Immunology)

== HIV infection ==

Midkine binds to cell-surface [[nucleolin]] as a low affinity receptor. This binding can inhibit HIV infection.<ref name="pmid12147681">{{cite journal |vauthors=Said EA, Krust B, Nisole S, Svab J, Briand JP, Hovanessian AG | title = The anti-HIV cytokine midkine binds the cell surface-expressed nucleolin as a low affinity receptor | journal = J. Biol. Chem. | volume = 277 | issue = 40 | pages = 37492–502 |date=October 2002 | pmid = 12147681 | doi = 10.1074/jbc.M201194200 | url =  }}</ref>

== Trivia ==
* In the [[Japan]]ese film "[[L: Change the World]]", Midkine is used as a major plot element, as it is used in a vaccine to treat the [[ebola virus]] combined with [[influenza]], from spreading.

== References ==
{{Reflist}}

== Further reading ==
{{Refbegin | 2}}
{{PBB_Further_reading
| citations =
*{{cite journal   |vauthors=Uehara K, Matsubara S, Kadomatsu K, etal |title=Genomic structure of human midkine (MK), a retinoic acid-responsive growth/differentiation factor |journal=J. Biochem. |volume=111 |issue= 5 |pages= 563–7 |year= 1992 |pmid= 1639750 |doi=  }}
*{{cite journal   |vauthors=Wujek JR, Haleem-Smith H, Yamada Y, etal |title=Evidence that the B2 chain of laminin is responsible for the neurite outgrowth-promoting activity of astrocyte extracellular matrix |journal=Brain Res. Dev. Brain Res. |volume=55 |issue= 2 |pages= 237–47 |year= 1991 |pmid= 1701366 |doi=10.1016/0165-3806(90)90205-D  }}
*{{cite journal   |vauthors=Kretschmer PJ, Fairhurst JL, Decker MM, etal |title=Cloning, characterization and developmental regulation of two members of a novel human gene family of neurite outgrowth-promoting proteins |journal=Growth Factors |volume=5 |issue= 2 |pages= 99–114 |year= 1992 |pmid= 1768439 |doi=10.3109/08977199109000275  }}
*{{cite journal   |vauthors=Shoyab M, McDonald VL, Dick K, etal |title=Amphiregulin-associated protein: complete amino acid sequence of a protein produced by the 12-0-tetradecanoylphorbol-13-acetate-treated human breast adenocarcinoma cell line MCF-7 |journal=Biochem. Biophys. Res. Commun. |volume=179 |issue= 1 |pages= 572–8 |year= 1991 |pmid= 1883381 |doi=10.1016/0006-291X(91)91409-6  }}
*{{cite journal   |vauthors=Tsutsui J, Uehara K, Kadomatsu K, etal |title=A new family of heparin-binding factors: strong conservation of midkine (MK) sequences between the human and the mouse |journal=Biochem. Biophys. Res. Commun. |volume=176 |issue= 2 |pages= 792–7 |year= 1991 |pmid= 2025291 |doi=10.1016/S0006-291X(05)80255-4  }}
*{{cite journal   |vauthors=O'Hara B, Jenkins NA, Gilbert DJ, etal |title=Chromosomal assignment of the heparin-binding cytokine genes MDK and PTN in mouse and man |journal=Cytogenet. Cell Genet. |volume=69 |issue= 1–2 |pages= 40–3 |year= 1995 |pmid= 7835084 |doi=10.1159/000133934  }}
*{{cite journal   |vauthors=Fairhurst JL, Kretschmer PJ, Kovacs E, etal |title=Structure of the gene coding for the human retinoic acid-inducible factor, MK |journal=DNA Cell Biol. |volume=12 |issue= 2 |pages= 139–47 |year= 1993 |pmid= 8471163 |doi=10.1089/dna.1993.12.139  }}
*{{cite journal   |vauthors=Kojima T, Katsumi A, Yamazaki T, etal |title=Human ryudocan from endothelium-like cells binds basic fibroblast growth factor, midkine, and tissue factor pathway inhibitor |journal=J. Biol. Chem. |volume=271 |issue= 10 |pages= 5914–20 |year= 1996 |pmid= 8621465 |doi=10.1074/jbc.271.10.5914  }}
*{{cite journal   |vauthors=Mahoney SA, Perry M, Seddon A, etal |title=Transglutaminase forms midkine homodimers in cerebellar neurons and modulates the neurite-outgrowth response |journal=Biochem. Biophys. Res. Commun. |volume=224 |issue= 1 |pages= 147–52 |year= 1996 |pmid= 8694802 |doi= 10.1006/bbrc.1996.0998 }}
*{{cite journal   |vauthors=Nakanishi T, Kadomatsu K, Okamoto T, etal |title=Expression of syndecan-1 and -3 during embryogenesis of the central nervous system in relation to binding with midkine |journal=J. Biochem. |volume=121 |issue= 2 |pages= 197–205 |year= 1997 |pmid= 9089390 |doi=  }}
*{{cite journal   |vauthors=Iwasaki W, Nagata K, Hatanaka H, etal |title=Solution structure of midkine, a new heparin-binding growth factor |journal=EMBO J. |volume=16 |issue= 23 |pages= 6936–46 |year= 1998 |pmid= 9384573 |doi= 10.1093/emboj/16.23.6936  | pmc=1170297 }}
*{{cite journal   |vauthors=Ratovitski EA, Kotzbauer PT, Milbrandt J, etal |title=Midkine induces tumor cell proliferation and binds to a high affinity signaling receptor associated with JAK tyrosine kinases |journal=J. Biol. Chem. |volume=273 |issue= 6 |pages= 3654–60 |year= 1998 |pmid= 9452495 |doi=10.1074/jbc.273.6.3654  }}
*{{cite journal   |vauthors=Maeda N, Ichihara-Tanaka K, Kimura T, etal |title=A receptor-like protein-tyrosine phosphatase PTPzeta/RPTPbeta binds a heparin-binding growth factor midkine. Involvement of arginine 78 of midkine in the high affinity binding to PTPzeta |journal=J. Biol. Chem. |volume=274 |issue= 18 |pages= 12474–9 |year= 1999 |pmid= 10212223 |doi=10.1074/jbc.274.18.12474  }}
*{{cite journal   |vauthors=Meng K, Rodriguez-Peña A, Dimitrov T, etal |title=Pleiotrophin signals increased tyrosine phosphorylation of β-catenin through inactivation of the intrinsic catalytic activity of the receptor-type protein tyrosine phosphatase β/ζ |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=97 |issue= 6 |pages= 2603–8 |year= 2000 |pmid= 10706604 |doi= 10.1073/pnas.020487997  | pmc=15975 }}
*{{cite journal   |vauthors=Muramatsu H, Zou K, Sakaguchi N, etal |title=LDL receptor-related protein as a component of the midkine receptor |journal=Biochem. Biophys. Res. Commun. |volume=270 |issue= 3 |pages= 936–41 |year= 2000 |pmid= 10772929 |doi= 10.1006/bbrc.2000.2549 }}
*{{cite journal   |vauthors=Kato M, Maeta H, Kato S, etal |title=Immunohistochemical and in situ hybridization analyses of midkine expression in thyroid papillary carcinoma |journal=Mod. Pathol. |volume=13 |issue= 10 |pages= 1060–5 |year= 2001 |pmid= 11048798 |doi= 10.1038/modpathol.3880195 }}
*{{cite journal  |vauthors=Hayashi K, Kadomatsu K, Muramatsu T |title=Requirement of chondroitin sulfate/dermatan sulfate recognition in midkine-dependent migration of macrophages |journal=Glycoconj. J. |volume=18 |issue= 5 |pages= 401–6 |year= 2002 |pmid= 11925507 |doi=10.1023/A:1014864131288  }}
*{{cite journal   |vauthors=Sumi Y, Muramatsu H, Takei Y, etal |title=Midkine, a heparin-binding growth factor, promotes growth and glycosaminoglycan synthesis of endothelial cells through its action on smooth muscle cells in an artificial blood vessel model |journal=J. Cell Sci. |volume=115 |issue= Pt 13 |pages= 2659–67 |year= 2002 |pmid= 12077357 |doi=  }}
*{{cite journal   |vauthors=Stoica GE, Kuo A, Powers C, etal |title=Midkine binds to anaplastic lymphoma kinase (ALK) and acts as a growth factor for different cell types |journal=J. Biol. Chem. |volume=277 |issue= 39 |pages= 35990–8 |year= 2002 |pmid= 12122009 |doi= 10.1074/jbc.M205749200 }}
}}
{{Refend}}
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