RPL36

Summary

RPL36 (ribosomal protein L36, HGNC:13631) is a protein-coding gene on chromosome 19p13.3, encoding RPL36 alternative reading frame protein (C0HME6). Inhibits C2CD2L/TMEM24-dependent transport of phosphatidylinositol, the precursor of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), from its site of synthesis in the endoplasmic reticulum to the cell membrane. It is a common-essential gene (DepMap: required in 100.0% of cancer cell lines).

Ribosomes, the organelles that catalyze protein synthesis, consist of a small 40S subunit and a large 60S subunit. Together these subunits are composed of 4 RNA species and approximately 80 structurally distinct proteins. This gene encodes a ribosomal protein that is a component of the 60S subunit. The protein belongs to the L36E family of ribosomal proteins. It is located in the cytoplasm. Transcript variants derived from alternative splicing exist; they encode the same protein. As is typical for genes encoding ribosomal proteins, there are multiple processed pseudogenes of this gene dispersed through the genome.

Source: NCBI Gene 25873 — RefSeq curated summary.

At a glance

• Clinical variants (ClinVar): 22 total
• Cancer dependency (DepMap): dependent in 100.0% of screened cell lines (common-essential)
• MANE Select transcript: NM_033643

Identifiers

Gene identifiers

Field	Value
HGNC ID	HGNC:13631
Approved symbol	RPL36
Name	ribosomal protein L36
Location	19p13.3
Locus type	gene with protein product
Status	Approved
Aliases	DKFZp566B023, L36, eL36
Ensembl gene	ENSG00000130255
Ensembl biotype	protein_coding
OMIM	617893
Entrez	25873

Gene structure

Transcript identifiers

Ensembl transcripts: 19 — 17 protein_coding, 1 protein_coding_CDS_not_defined, 1 retained_intron

ENST00000347512, ENST00000394580, ENST00000577222, ENST00000579446, ENST00000579649, ENST00000582380, ENST00000582463, ENST00000590786, ENST00000913550, ENST00000913551, ENST00000913552, ENST00000913553, ENST00000913554, ENST00000913555, ENST00000913556, ENST00000913557, ENST00000913558, ENST00000913559, ENST00000913560

RefSeq mRNA: 2 — MANE Select: NM_033643 NM_015414, NM_033643

CCDS: CCDS12147

Canonical transcript exons

ENST00000347512 — 4 exons

Exon	Start	End
ENSE00001158924	5691319	5691453
ENSE00002715318	5691532	5691875
ENSE00002725662	5690295	5690327
ENSE00002742583	5690506	5690600

Expression profiles

Bgee: expression breadth ubiquitous, 288 present calls, max score 99.80.

FANTOM5 (CAGE): breadth ubiquitous, TPM avg 442.8576 / max 2396.3547, expressed in 1827 samples.

FANTOM5 promoters (4 alternative TSS)

Promoter ID	TPM avg	Samples expressed
173424	299.9755	1827
173423	139.9757	1824
173415	3.3874	1178
173425	2.9064	1287

Top tissues by expression

288 total, by Bgee expression score (0-100, higher = more expressed):

Tissue	Anatomy ID	Expression score	Quality
ganglionic eminence	UBERON:0004023	99.80	gold quality
cortical plate	UBERON:0005343	99.78	gold quality
left ovary	UBERON:0002119	99.77	gold quality
ventricular zone	UBERON:0003053	99.77	gold quality
embryo	UBERON:0000922	99.74	gold quality
ovary	UBERON:0000992	99.74	gold quality
right ovary	UBERON:0002118	99.74	gold quality
olfactory segment of nasal mucosa	UBERON:0005386	99.73	gold quality
left adrenal gland cortex	UBERON:0035825	99.73	gold quality
right adrenal gland	UBERON:0001233	99.72	gold quality
left adrenal gland	UBERON:0001234	99.72	gold quality
right uterine tube	UBERON:0001302	99.72	gold quality
skin of abdomen	UBERON:0001416	99.72	gold quality
adrenal cortex	UBERON:0001235	99.71	gold quality
skin of leg	UBERON:0001511	99.71	gold quality
penis	UBERON:0000989	99.70	gold quality
right adrenal gland cortex	UBERON:0035827	99.70	gold quality
endocervix	UBERON:0000458	99.69	gold quality
lower esophagus mucosa	UBERON:0035834	99.69	gold quality
granulocyte	CL:0000094	99.68	gold quality
nipple	UBERON:0002030	99.68	gold quality
adenohypophysis	UBERON:0002196	99.68	gold quality
body of pancreas	UBERON:0001150	99.67	gold quality
zone of skin	UBERON:0000014	99.66	gold quality
body of uterus	UBERON:0009853	99.66	gold quality
ectocervix	UBERON:0012249	99.66	gold quality
adrenal gland	UBERON:0002369	99.65	gold quality
gingival epithelium	UBERON:0001949	99.64	gold quality
prostate gland	UBERON:0002367	99.64	gold quality
pituitary gland	UBERON:0000007	99.63	gold quality

Single-cell (SCXA)

Detected in 44 experiment(s), a significant marker in 10.

Experiment	Marker?	Max mean expression
E-MTAB-9067	yes	6251.29
E-CURD-122	yes	97.72
E-CURD-88	yes	66.07
E-MTAB-9221	yes	57.37
E-CURD-112	yes	41.41
E-MTAB-10042	yes	14.52
E-HCAD-35	yes	9.40
E-MTAB-9801	yes	6.61
E-HCAD-31	yes	4.41
E-GEOD-125970	no	7118.15
E-MTAB-8410	no	6305.17
E-MTAB-6701	no	6226.33
E-CURD-85	no	5724.76
E-HCAD-4	no	5595.89
E-HCAD-24	no	5513.41

Regulation

Is transcription factor: no

Functional genomics

DepMap (CRISPR cell-line fitness): dependent in 100.0% of screened cell lines, common-essential.

Literature-anchored findings (GeneRIF, showing 4)

• RPL36 may be involved in the early stage of hepatocarcinogenesis, and it can be used as an independent and potential prognostic marker for resected hepatocellular carcinoma. (PMID:22029674)
• These results provide evidence for a novel cell cycle regulatory network in glioma comprising the Long non-coding PLAC2 along with STAT1 and RPL36. (PMID:28922548)
• Alt-RPL36 downregulates the PI3K-AKT-mTOR signaling pathway by interacting with TMEM24. (PMID:33479206)
• The m6A reader IGF2BP1 attenuates the stability of RPL36 and cell proliferation to mediate benzene hematotoxicity by recognizing m6A modification. (PMID:38367942)

Cross-species orthologs

6 orthologs

Organism	Symbol	Gene ID
danio_rerio	rpl36	ENSDARG00000100588
mus_musculus	Rpl36	ENSMUSG00000057863
rattus_norvegicus	Rpl36l2	ENSRNOG00000002340
rattus_norvegicus	AABR07007675.1	ENSRNOG00000029988
rattus_norvegicus	Rpl36l3	ENSRNOG00000031947
rattus_norvegicus		ENSRNOG00000079694

Protein

Protein identifiers

RPL36 alternative reading frame protein — C0HME6 (reviewed: C0HME6, Q9Y3U8)

All UniProt accessions (3): Q9Y3U8, J3KTD3, J3QSB5

UniProt curated annotations — full annotation on UniProt →

Function. Inhibits C2CD2L/TMEM24-dependent transport of phosphatidylinositol, the precursor of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), from its site of synthesis in the endoplasmic reticulum to the cell membrane. This leads to down-regulation of the PI3K-AKT-mTOR signaling pathway.

Subunit / interactions. Interacts (when phosphorylated) with C2CD2L/TMEM24 (via the SMP-LBD and C2 domains); the interaction is required for localization of alt-RPL36 to the endoplasmic reticulum and inhibits C2CD2L-dependent transport of phosphatidylinositol from the endoplasmic reticulum to the cell membrane.

Subcellular location. Endoplasmic reticulum.

Post-translational modifications. Phosphorylation is regulated by cytosolic calcium levels. Increased calcium levels reduce phosphorylation at Ser-19, Ser-140 and Ser-142 but increase phosphorylation at Ser-22.

Miscellaneous. Produced by an alternative reading frame of the RPL36 gene which also produces ribosomal protein L36, a component of the large ribosomal subunit. Translation of alt-RPL36 initiates from a non-canonical GUG start codon upstream of the AUG start codon used to produce ribosomal protein L36.

RefSeq proteins (2): NP_056229, NP_378669* (*=MANE)

Domains & families (InterPro)

ID	Name	Type
IPR000509	Ribosomal_eL36	Family
IPR038097	Ribosomal_eL36_sf	Homologous_superfamily

Pfam: PF01158

UniProt features (21 total): mutagenesis site 11, modified residue 5, chain 2, initiator methionine 1, sequence variant 1, sequence conflict 1

Structure

Experimental structures (PDB)

194 structures, top 30 by resolution.

PDB	Method	Resolution (Å)
8A3D	ELECTRON MICROSCOPY	1.67
8GLP	ELECTRON MICROSCOPY	1.67
8QYX	ELECTRON MICROSCOPY	1.78
8QOI	ELECTRON MICROSCOPY	1.9
9O3W	ELECTRON MICROSCOPY	1.9
8YOO	ELECTRON MICROSCOPY	2
9C3H	ELECTRON MICROSCOPY	2
9I2D	ELECTRON MICROSCOPY	2.19
9PBE	ELECTRON MICROSCOPY	2.19
8QFD	ELECTRON MICROSCOPY	2.2
8YOP	ELECTRON MICROSCOPY	2.2
9GUL	ELECTRON MICROSCOPY	2.2
9O3V	ELECTRON MICROSCOPY	2.2
9O3Y	ELECTRON MICROSCOPY	2.2
8JDK	ELECTRON MICROSCOPY	2.26
8G5Y	ELECTRON MICROSCOPY	2.29
9S3D	ELECTRON MICROSCOPY	2.32
9RPV	ELECTRON MICROSCOPY	2.35
9S3B	ELECTRON MICROSCOPY	2.38
7OW7	ELECTRON MICROSCOPY	2.4
8K2C	ELECTRON MICROSCOPY	2.4
8XSX	ELECTRON MICROSCOPY	2.4
9SPF	ELECTRON MICROSCOPY	2.4
9SPI	ELECTRON MICROSCOPY	2.4
8JDL	ELECTRON MICROSCOPY	2.42
9S3C	ELECTRON MICROSCOPY	2.42
8FKV	ELECTRON MICROSCOPY	2.47
9QLO	ELECTRON MICROSCOPY	2.47
8FLE	ELECTRON MICROSCOPY	2.48
9P8B	ELECTRON MICROSCOPY	2.48

Predicted structure (AlphaFold)

Model	pLDDT	Fraction very-high
AF-Q9Y3U8-F1	93.20	0.88

No AlphaFold model available for C0HME6 — AlphaFold DB does not currently provide models for proteins above ~3000 aa.

Functional residue map

Curated UniProt residues grouped by drug-discovery relevance — catalytic, ligand-binding, modification, and mutation-validated positions. Source: UniProtKB sequence features.

C0HME6 (canonical)

Post-translational modifications (4): 19, 22, 140, 142

Mutagenesis-validated functional residues (11):

Position	Phenotype
98	reduces alt-rpl36 protein levels. reduces phosphorylation. reduces interaction with c2cd2l.
104	no effect on alt-rpl36 protein levels. reduces phosphorylation. reduces interaction with c2cd2l.
115	reduces alt-rpl36 protein levels. reduces phosphorylation. reduces interaction with c2cd2l.
118	no effect on alt-rpl36 protein levels. reduces phosphorylation. no effect on interaction with c2cd2l.
140	reduces phosphorylation. abolishes phosphorylation and abolishes interaction with c2cd2l; when associated with a-19; a-2
142	reduces phosphorylation. abolishes phosphorylation and abolishes interaction with c2cd2l; when associated with a-19; a-2
19	reduces phosphorylation. abolishes phosphorylation and abolishes interaction with c2cd2l; when associated with a-22; a-1
22	reduces phosphorylation. abolishes phosphorylation and abolishes interaction with c2cd2l; when associated with a-19; a-1
50	reduces alt-rpl36 protein levels. reduces phosphorylation. abolishes interaction with c2cd2l.
73	no effect on alt-rpl36 protein levels. no effect on phosphorylation. reduces interaction with c2cd2l.
93	reduces alt-rpl36 protein levels. reduces phosphorylation. no effect on interaction with c2cd2l.

Q9Y3U8

Post-translational modifications (1): 62

Function

Pathways and Gene Ontology

Reactome pathways

16 pathways

ID	Pathway
R-HSA-156827	L13a-mediated translational silencing of Ceruloplasmin expression
R-HSA-156902	Peptide chain elongation
R-HSA-1799339	SRP-dependent cotranslational protein targeting to membrane
R-HSA-192823	Viral mRNA Translation
R-HSA-2408557	Selenocysteine synthesis
R-HSA-6791226	Major pathway of rRNA processing in the nucleolus and cytosol
R-HSA-72689	Formation of a pool of free 40S subunits
R-HSA-72706	GTP hydrolysis and joining of the 60S ribosomal subunit
R-HSA-72764	Eukaryotic Translation Termination
R-HSA-9010553	Regulation of expression of SLITs and ROBOs
R-HSA-9633012	Response of EIF2AK4 (GCN2) to amino acid deficiency
R-HSA-975956	Nonsense Mediated Decay (NMD) independent of the Exon Junction Complex (EJC)
R-HSA-975957	Nonsense Mediated Decay (NMD) enhanced by the Exon Junction Complex (EJC)
R-HSA-9954709	Ribosome Quality Control (RQC) complex extracts and degrades nascent peptide
R-HSA-9954714	PELO:HBS1L and ABCE1 dissociate a ribosome on a non-stop mRNA
R-HSA-9954716	ZNF598 and the Ribosome-associated Quality Trigger (RQT) complex dissociate a ribosome stalled on a no-go mRNA

MSigDB gene sets: 249 (showing top): GOBP_CYTOPLASMIC_TRANSLATION, XU_GH1_AUTOCRINE_TARGETS_UP, GOBP_STRIATED_MUSCLE_CELL_DIFFERENTIATION, GOBP_MALE_GAMETE_GENERATION, GOBP_NEGATIVE_REGULATION_OF_CELLULAR_COMPONENT_ORGANIZATION, GOBP_TRANSLATION, GOBP_MUSCLE_STRUCTURE_DEVELOPMENT, GOBP_MUSCLE_CONTRACTION, GAZDA_DIAMOND_BLACKFAN_ANEMIA_PROGENITOR_DN, GOBP_REGULATION_OF_SYNCYTIUM_FORMATION_BY_PLASMA_MEMBRANE_FUSION, GOMF_STRUCTURAL_CONSTITUENT_OF_RIBOSOME, GNF2_FBL, SPIELMAN_LYMPHOBLAST_EUROPEAN_VS_ASIAN_UP, GOBP_NEGATIVE_REGULATION_OF_DEVELOPMENTAL_PROCESS, GOBP_MYOTUBE_DIFFERENTIATION

GO Biological Process (2): cytoplasmic translation (GO:0002181), translation (GO:0006412)

GO Molecular Function (3): RNA binding (GO:0003723), structural constituent of ribosome (GO:0003735), protein binding (GO:0005515)

GO Cellular Component (9): nucleolus (GO:0005730), cytoplasm (GO:0005737), cytosol (GO:0005829), membrane (GO:0016020), cytosolic large ribosomal subunit (GO:0022625), cytosolic ribosome (GO:0022626), synapse (GO:0045202), ribosome (GO:0005840), ribonucleoprotein complex (GO:1990904)

Reactome top-level categories

Rollup of top-11 pathways:

Category	Pathways
Ribosome-associated quality control	3
Translation	2
Cap-dependent Translation Initiation	2
Nonsense-Mediated Decay (NMD)	2
Eukaryotic Translation Initiation	1
Eukaryotic Translation Elongation	1
Influenza Viral RNA Transcription and Replication	1
Selenoamino acid metabolism	1
rRNA processing in the nucleus and cytosol	1
Signaling by ROBO receptors	1
Cellular response to starvation	1

GO top-level categories

Rollup of top GO terms by namespace:

Category	Terms
cellular anatomical structure	3
ribosome	2
intracellular membraneless organelle	2
translation	1
peptidyltransferase activity	1
translational initiation	1
translational elongation	1
translational termination	1
macromolecule biosynthetic process	1
protein metabolic process	1
protein biosynthetic process	1
nucleic acid binding	1
structural molecule activity	1
binding	1
nuclear lumen	1
intracellular anatomical structure	1
cytoplasm	1
large ribosomal subunit	1
cytosolic ribosome	1
cytosol	1
cell junction	1
protein-containing complex	1

Protein interactions and networks

STRING

0 interactions, top by confidence (×1000):

IntAct

0 interactions, top by confidence:

SIGNOR signaling

0 interactions.

Disease & clinical

Clinical variants and AI predictions

ClinVar

22 variants total. Per-class counts are floors (≥ shown; pagination cap):

Classification	Count (floor)
Pathogenic	0
Likely pathogenic	0
Uncertain significance	10
Likely benign	1
Benign	1

Top pathogenic / likely-pathogenic (0)

SpliceAI

3141 predictions. Top by Δscore:

Variant	Effect	Δscore
19:5678646:TGC:T	acceptor_gain	1.0000
19:5678649:C:CC	acceptor_gain	1.0000
19:5679584:ACCTG:A	donor_loss	1.0000
19:5679621:A:AC	donor_gain	1.0000
19:5679622:C:CC	donor_gain	1.0000
19:5679622:CTGG:C	donor_gain	1.0000
19:5679651:C:CT	donor_gain	1.0000
19:5679652:C:CT	donor_gain	1.0000
19:5679759:GGAAC:G	acceptor_gain	1.0000
19:5679760:GAAC:G	acceptor_gain	1.0000
19:5679761:AAC:A	acceptor_gain	1.0000
19:5679762:AC:A	acceptor_gain	1.0000
19:5679763:CC:C	acceptor_gain	1.0000
19:5679764:C:CC	acceptor_gain	1.0000
19:5679764:CTG:C	acceptor_loss	1.0000
19:5679771:C:CT	acceptor_gain	1.0000
19:5680532:T:TA	donor_gain	1.0000
19:5686523:GCTGG:G	donor_gain	1.0000
19:5686524:C:G	donor_gain	1.0000
19:5687500:CAG:C	acceptor_loss	1.0000
19:5687501:A:AG	acceptor_gain	1.0000
19:5687502:G:A	acceptor_loss	1.0000
19:5687502:G:GG	acceptor_gain	1.0000
19:5687502:GGCC:G	acceptor_gain	1.0000
19:5687533:A:AG	acceptor_gain	1.0000
19:5687533:ACTC:A	acceptor_gain	1.0000
19:5687536:C:A	acceptor_gain	1.0000
19:5687664:GTCAG:G	donor_gain	1.0000
19:5687665:TCAGG:T	donor_loss	1.0000
19:5687666:CAGGT:C	donor_loss	1.0000

AlphaMissense

685 scored. Top likely-pathogenic:

Variant	Protein change	am_pathogenicity
19:5691391:C:A	R56S	1.000
19:5691395:C:A	A57D	1.000
19:5691400:G:A	E59K	1.000
19:5691404:T:C	L60S	1.000
19:5691407:T:C	L61P	1.000
19:5691421:G:C	D66H	1.000
19:5691422:A:T	D66V	1.000
19:5691424:A:G	K67E	1.000
19:5691425:A:T	K67I	1.000
19:5691426:A:C	K67N	1.000
19:5691426:A:T	K67N	1.000
19:5691431:C:A	A69D	1.000
19:5691434:T:A	L70H	1.000
19:5691434:T:C	L70P	1.000
19:5691439:T:C	F72L	1.000
19:5691440:T:C	F72S	1.000
19:5691441:T:A	F72L	1.000
19:5691441:T:G	F72L	1.000
19:5691447:G:C	K74N	1.000
19:5691447:G:T	K74N	1.000
19:5691452:G:T	R76M	1.000
19:5691535:G:A	G78R	1.000
19:5691535:G:C	G78R	1.000
19:5691535:G:T	G78W	1.000
19:5691536:G:A	G78E	1.000
19:5691536:G:T	G78V	1.000
19:5691551:C:T	A83V	1.000
19:5691561:G:C	K86N	1.000
19:5691561:G:T	K86N	1.000
19:5691572:T:C	L90P	1.000

dbSNP variants (sampled 300 via entrez): RS1000418305 (19:5692305 T>A,C), RS1001159971 (19:5691638 C>T), RS1002071399 (19:5689016 T>C), RS1002103875 (19:5689343 C>A), RS1002413035 (19:5690868 C>G,T), RS1002730634 (19:5689746 C>T), RS1004405522 (19:5688586 G>A), RS1004806778 (19:5692333 A>C,G), RS1005893551 (19:5688413 C>T), RS1006273770 (19:5690915 G>A), RS1006568382 (19:5690742 G>A), RS1006641704 (19:5691001 G>A), RS1006759096 (19:5691123 G>A,C), RS1008299431 (19:5688913 T>C), RS1008767930 (19:5689200 T>C)

Disease associations

OMIM: gene MIM:617893 | disease phenotypes:

GenCC curated gene-disease

Mondo (1): myoepithelial tumor (MONDO:0002380)

Orphanet (0):

HPO phenotypes

0 total (0 of 0 shown, HPO-id order):

GWAS associations

0 associations (top):

MeSH disease descriptors (1)

Descriptor	Name	Tree numbers
D009208	Myoepithelioma	C04.557.435.585

Drugs & pharmacology

Drug and pharmacology data

Is drug target: no

PharmGKB: 1 entry (VIP=true, CPIC=false)

CTD chemical–gene interactions

49 total (human), top 30 by PubMed support.

Chemical	Actions (top 5)	PubMed papers
bisphenol A	affects expression, affects cotreatment, increases methylation, decreases expression, increases expression	5
sodium arsenite	decreases expression, increases expression	3
Smoke	decreases expression, increases abundance	2
Tobacco Smoke Pollution	decreases expression, increases methylation	2
Valproic Acid	affects cotreatment, increases expression, increases methylation	2
Particulate Matter	decreases expression, increases expression	2
aristolochic acid I	decreases expression	1
quinone	decreases expression, decreases reaction, affects binding, increases reaction, decreases methylation (+1 more)	1
pyrogallol 1,3-dimethyl ether	affects cotreatment, affects localization, increases expression, decreases expression	1
tris(2-butoxyethyl) phosphate	increases expression	1
arsenite	affects binding, increases reaction	1
methylparaben	decreases expression	1
epigallocatechin gallate	increases expression	1
azoxystrobin	increases expression	1
chloropicrin	decreases expression	1
perfluoro-n-nonanoic acid	increases expression	1
deguelin	increases expression	1
fenpyroximate	increases expression	1
4-chloro-N-((4-(1,1-dimethylethyl)phenyl)methyl)-3-ethyl-1-methyl-1H-pyrazole-5-carboxamide	increases expression	1
4-(5-benzo(1,3)dioxol-5-yl-4-pyridin-2-yl-1H-imidazol-2-yl)benzamide	affects cotreatment, decreases expression	1
pyrimidifen	increases expression	1
bisphenol B	increases expression	1
abrine	decreases expression	1
pyrachlostrobin	increases expression	1
jinfukang	increases expression	1
LDN 193189	affects cotreatment, decreases expression	1
picoxystrobin	increases expression	1
4-(4-((5-(4,5-dimethyl-2-nitrophenyl)-2-furanyl)methylene)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl)benzoic acid	decreases expression	1
Sunitinib	increases expression	1
Fulvestrant	affects cotreatment, increases methylation	1

Clinical trials (associated diseases)

5 trials via MONDO — disease-level, not drug-specific.

Trial	Phase	Status	Title
NCT03600649	PHASE1	UNKNOWN	Clinical Trial of SP-2577 (Seclidemstat) in Patients With Relapsed or Refractory Ewing or Ewing-related Sarcomas
NCT05266196	PHASE1/PHASE2	UNKNOWN	A Rollover Protocol to Allow for Continued Access to the LSD1 Inhibitor Seclidemstat (SP-2577)
NCT06239272	PHASE1/PHASE2	RECRUITING	NRSTS2021, A Risk Adapted Study Evaluating Maintenance Pazopanib, Limited Margin, Dose-Escalated Radiation Therapy and Selinexor in Non-Rhabdomyosarcoma Soft Tissue Sarcoma (NRSTS)
NCT06625190	PHASE1/PHASE2	RECRUITING	Alpha/Beta T and B Cell Depletion With Zoledronic Acid for Solid Tumors
NCT06244420	Not specified	COMPLETED	Malignant Myoepithelioma of Bone and Soft Tissues: Diagnostic Imaging and Histology in Relation to Prognosis