Chordoma Foundation

TGFβ

Transforming Growth Factor β is a regulatory cytokine that has tumor suppressive effects. However, it also plays a role in modulating cell invasion, regulating immune processes, and making micro-environmental modifications within the body.1 It is also known to be a potent inducer of the epithelial-mesenchymal transition (EMT).2

Relevant Locations: TGFB1 at 19q13, TGFBR1 at 9q22, and TGFBR2 at 3p22

By disrupting the TGFβ pathway either through direct inactivation of its main components or through downstream events, cancer cells can suppress the anti-tumor influences of TGFβ and take advantage of its dual role in cellular invasion.

TGFβ in Chordoma

Evidence suggests that the TGFβ signaling pathway acts upstream of brachyury (of known importance in chordoma) and plays a role in bone and cartilage development.3 TGFβ’s relationship with brachyury and growing body of evidence suggesting that genes involved in cartilage development are important in the development of chordoma4  have called attention to the pathway as a possible therapeutic target. While abnormalities involving genes of the pathway have been identified in chordomas, but the importance of TGFβ signaling in chordoma and the consequences of its inhibition have not been extensively explored.

Molecular Evidence


Copy Number Variation

Chromosomal Aberrations: Partial gains of chromosome 19, where the gene TGFB1 resides, have been observed in many chordoma tumor samples.5 6 7 Losses of chromosomal regions harboring TGFB receptors TGFBR1 and TGFBR2 (located on chromosomes 9 and 3, respectively) have also been reported.8

Gene Copy Number Variation: Deletion of the TGFB1 locus (and relocation to chromosome 5q21) has been detected in 5/21 chordomas tested.9

Gene Expression

TGFβ1 gene expression was found to be significantly higher in INI1-loss chordoma compared to INI1-positive chordoma.10

Upregulation of miR-671-5p and miR-193a-5p have been observed in SMARCB1/INI1-immunonegative cases and are thought to downregulate TGF-β signaling in pediatric chordoma.10

Downregulation of miR-16-5p has been observed in chordoma compared to nucleus pulposus samples. miR-16-5p is believed to have a tumor suppressive role and target Smad3, a critical component of the TGF-β signaling pathway. High Smad3 expression in chordoma was correlated with surrounding invasion.11

Protein Expression

TGFβ was detected in 2/3 chordoma samples tested.12 miRNAs known to target TGFB1 were found to be downregulated in 13 chordoma samples analyzed.13 In a more recent study, TGFβ was detected in 22/23 samples tested, and expression level was suggested to correlate with degree of bone invasion.14

Preclinical Evidence


In-vitro Efficacy

  • Overexpression of miR-16-5p or Knockdown of Smad3: Independent overexpression of miR-16-5p or knockdown of Smad3 had similar effects in U-CH1 and U-CH2 cell lines. Each significantly suppressed cell migration and invasion and significantly upregulated the expression of E-cadherin and downregulated the expression of N-cadherin and vimentin. Overexpression of miR-16-5p was also shown to suppress cell proliferation in vitro.11

In-vivo Efficacy

  • Overexpression of miR-16-5p: Overexpression of miR-16-5p in a U-CH1 xenograft model resulted in significantly decreased tumor volume compared to control suggesting that that miR-16-5p may act as a suppressor of chordoma proliferation.11

Clinical Evidence


 Phase I Trial

  • M7824 (MSB0011359C): M7824 is a bifunctional fusion protein composed of a monoclonal antibody against PD-L1 fused to a TGF-β “trap”. Treatment of a chordoma patient with 20mg/kg M7824 resulted in early progression and drug discontinuation on day 85 followed by late-onset tumor shrinkage observed on day 280 despite no further therapeutic interventions after discontinuing M7824.15

References

1.
Massagué J. TGFbeta in Cancer. Cell. 2008;134(2):215-230. [PubMed]
2.
Yang L, Pang Y, Moses H. TGF-beta and immune cells: an important regulatory axis in the tumor microenvironment and progression. Trends Immunol. 2010;31(6):220-227. [PubMed]
3.
Nibu Y, José-Edwards D, Di G. From notochord formation to hereditary chordoma: the many roles of Brachyury. Biomed Res Int. 2013;2013:826435. [PubMed]
4.
Henderson S, Guiliano D, Presneau N, et al. A molecular map of mesenchymal tumors. Genome Biol. 2005;6(9):R76. [PubMed]
5.
Le L, Nielsen G, Rosenberg A, et al. Recurrent chromosomal copy number alterations in sporadic chordomas. PLoS One. 2011;6(5):e18846. [PubMed]
6.
Diaz R, Guduk M, Romagnuolo R, et al. High-resolution whole-genome analysis of skull base chordomas implicates FHIT loss in chordoma pathogenesis. Neoplasia. 2012;14(9):788-798. [PubMed]
7.
Kitamura Y, Sasaki H, Kimura T, et al. Molecular and clinical risk factors for recurrence of skull base chordomas: gain on chromosome 2p, expression of brachyury, and lack of irradiation negatively correlate with patient prognosis. J Neuropathol Exp Neurol. 2013;72(9):816-823. [PubMed]
8.
Rinner B, Weinhaeusel A, Lohberger B, et al. Chordoma characterization of significant changes of the DNA methylation pattern. PLoS One. 2013;8(3):e56609. [PubMed]
9.
Hallor K, Staaf J, Jönsson G, et al. Frequent deletion of the CDKN2A locus in chordoma: analysis of chromosomal imbalances using array comparative genomic hybridisation. Br J Cancer. 2008;98(2):434-442. [PubMed]
10.
Malgulwar P, Pathak P, Singh M, et al. Downregulation of SMARCB1/INI1 expression in pediatric chordomas correlates with upregulation of miR-671-5p and miR-193a-5p expressions. Brain Tumor Pathol. 2017;34(4):155-159. [PubMed]
11.
Zhang H, Yang K, Ren T, Huang Y, Tang X, Guo W. miR-16-5p inhibits chordoma cell proliferation, invasion and metastasis by targeting Smad3. Cell Death Dis. 2018;9(6):680. [PubMed]
12.
Mitsuhashi T, Watanabe M, Sasano H, Ono M. The expression of insulin-like growth factor-1(IGF-1), IGF- 1 receptor and transforming growth factor-β in chordoma [poster presentation]. XXVI Congress of the International Academy of Pathology. https://www.nature.com/modpathohttps://www.nature.com/modpathol/journal/v19/n3s/pdf/3800862a.pdf?foxtrotcallback=true. Published September 2006.
13.
Long C, Jiang L, Wei F, et al. Integrated miRNA-mRNA analysis revealing the potential roles of miRNAs in chordomas. PLoS One. 2013;8(6):e66676. [PubMed]
14.
Wu Z, Wang L, Guo Z, et al. Experimental study on differences in clivus chordoma bone invasion: an iTRAQ-based quantitative proteomic analysis. PLoS One. 2015;10(3):e0119523. [PubMed]
15.
Strauss J, Heery C, Schlom J, et al. Phase 1 trial of M7824 (MSB0011359C), a bifunctional fusion protein targeting PD-L1 and TGF-β, in advanced solid tumors. Clin Cancer Res. January 2018. [PubMed]