A novel protein derived from lamprey supraneural body tissue with efficient cytocidal actions against tumor cells
Pang et al. Cell Communication and Signaling
A novel protein derived from lamprey supraneural body tissue with efficient cytocidal actions against tumor cells
Yue Pang 0 1
Changzhi Li 0 1
Shiyue Wang 0 1
Wei Ba 0 1
Tao Yu 0 1
Guangying Pei 0 1
Dan Bi 0 1
Hongfang Liang 0 1
Xiong Pan 0 1
Ting Zhu 0 1
Meng Gou 0 1
Yinglun Han 0 1
Qingwei Li 0 1
0 Lamprey Research Center, Liaoning Normal University , Dalian 116081 , China
1 College of Life Science, Liaoning Normal University , Dalian 116081 , China
Background: In previous research, we found that cell secretion from the adult lamprey supraneural body tissues possesses cytocidal activity against tumor cells, but the protein with cytocidal activity was unidentified. Methods: A novel lamprey immune protein (LIP) as defense molecule was first purified and identified in jawless vertebrates (cyclostomes) using hydroxyapatite column and Q Sepharose Fast Flow column. After LIP stimulation, morphological changes of tumor cells were analysed and measured whether in vivo or in vitro. Results: LIP induces remarkable morphological changes in tumor cells, including cell blebbing, cytoskeletal alterations, mitochondrial fragmentation and endoplasmic reticulum vacuolation, and most of the cytoplasmic and organelle proteins are released following treatment with LIP. LIP evokes an elevation of intracellular calcium and inflammatory molecule levels. Our analysis of the cytotoxic mechanism suggests that LIP can upregulate the expression of caspase 1, RIPK1, RIP3 to trigger pyroptosis and necroptosis. To examine the effect of LIP in vivo, tumor xenograft experiments were performed, and the results indicated that LIP inhibits tumor growth without damage to mice. In addition, the cytotoxic action of LIP depended on the phosphatidylserine (PS) content of the cell membrane. Conclusions: These observations suggest that LIP plays a crucial role in tumor cell survival and growth. The findings will also help to elucidate the mechanisms of host defense in lamprey.
Lamprey; LIP; Cytotoxic activity; Inflammatory; Phosphatidylserine
Background
The adaptive immune system of jawed vertebrates can
remove exogenous pathogens or abnormal cells, primarily by
cytotoxicity against target cells. In addition to
antibodydependent cellular cytotoxicity and the antibody-mediated
classical complement pathway, cytotoxic T lymphocytes
(CTLs) are able to kill target cells infected by viruses [
1
].
The ability of CTLs to kill target cells primarily depends on
the amount of cytoplasmic granules, such as perforin and
granzyme. They induce programmed cell death in the
target cell, thus eliminating cells that have become
cancerous or are infected with viruses or bacteria [
2
]. In previous
research, we observed that lamprey antisera displayed
complement dependent cytolytic effects against bacteria and
tumor cells [
3
]. In this study, a novel protein was
discovered in the supraneural body (SB) of adult lamprey that has
cytotoxic activity against human MCF-7 and K562 cells.
We obtained the gene encoding this novel protein, called
lamprey immune protein (LIP), and examined the cytotoxic
activities of LIP against a variety of cultured human cells.
LIP was found to have strong cytocidal effects against
various human cells in vitro and in vivo. In addition, LIP
specifically bound to the plasma membrane of tumor cells
and then rapidly increased the membrane permeability and
dramatically altered the organelle morphologies. Our
analyses of the cytocidal effects of this protein demonstrate
the following: (i) LIP increases the membrane permeability
and alters the organelle morphologies; (ii) evokes an
elevation of intracellular calcium, and inflammatory molecule
levels; (iii) LIP preferentially kills tumor cells in vitro and in
vivo without damage to mice; (iv) LIP upregulates the
expression of caspase 1, RIPK1, RIP3 to trigger pyroptosis
and necroptosis, and (v) LIP specifically recognizes and
binds to PS on the plasma membrane of tumor cells. Thus,
LIP is a cell-discriminating and membrane-targeting
protein that causes irreversible intracellular decay in tumor
cells. Because LIP possesses highly selective cytotoxicity
toward human cells and has the potential to specifically
recognize and kill some classes of tumor cells, the
possibility of its application in medical and biological fields is
anticipated.
Methods
Animals and cell culture
Adult lampreys (Lethenteron camtschaticum) weighing
121-152 g were obtained in December 2015 from the
Tongjiang Valley of Songhua River, Heilongjiang Province,
China. These lampreys were kept at 10 °C in glass tanks
with recirculating fresh water at Liaoning Normal
University. The animal experiments were performed in
accordance with the regulations of the Animal Welfare and
Research Ethics Committee of the Institute of Dalian
Medical University’s Animal Care protocol (Permit
Number: SCXK2008-0002).
Human cells used, breast adenocarcinoma cell MCF-7,
hepatocyte cancer HepG2, c (...truncated)