Chondrosarcoma to LSJL gene expression

The study below shows that the genes upregulated in LSJL were very similar to the genes upregulated in chondrogenic human bone marrow mesenchymal stem cells(41.1%).  This provides further evidence that LSJL can cause chondroinduction in aged individuals since the majority 7 out of 8 subjects were over 21 and one was 74.

LSJL gene expression was done on the whole bone of mice whereas this was done in spheroid cultures of MSCs.  And many of the genes could also be expressed by osteoblasts.  However, LSJL upregulates the main chondrocyte differentiation gene Sox9 by over 3-fold whereas LSJL does not upregulate the main osteoblast differentiation gene Runx2 detect-ably over 2-fold.  Interestingly in the below study Sox9 is not upregulated in the chondrogenic normal MSCs.

Since LSJL was done on the whole bone and the area of the osteogenic portion of the bone is larger than the growth plate area you'd expect to have larger osteogenic gene expression than chondrogenic gene expression whereas in LSJL the opposite is observed with the exception of that Col1a1 is expressed at a higher fold than Col2a1. And in turn many of the osteogenic genes would be expected to be expressed in the hypertrophic. You have to take into account as well that growth plates are denser than osteoblasts in the bone marrow or osteocytes in the bone.  You also have to assume that ectopic chondrocyte differentiation is occurring within the bone marrow because our goal with LSJL is to induce ectopic chondrocyte differentiation in the bone marrow to form new growth plates.

However, I think you'd still expect for the osteoblast markers of the entire bone to increase more than the growth plates.

Thus, this study provides further evidence that LSJL can induce mesenchymal chondrocyte differentiation.

A chondrogenic gene expression signature in mesenchymal stem cells is a classifier of conventional central chondrosarcoma.

"Phenotypic and molecular parallels between the development of chondrosarcoma and the differentiation of chondrocytes in normal growth plate suggest that chondrosarcoma may arise from mesenchymal precursor cells driven towards chondrogenesis. We [compare] cartilaginous tumours and mesenchymal stem cells (MSCs). MSCs from eight donors were submitted to chondrogenic differentiation in spheroid cultures. Expression profiles of MSCs at days 0, 7, 14, 28 and 42 of chondrogenesis and of 18 chondrosarcomas with different histological grades were studied using a customized cDNA array. Hierarchical clustering of MSC gene expression during chondrogenesis allowed the classification of samples in a pre-chondrogenic and a chondrogenic cluster corresponding to the phenotypes of early and late differentiation stages. The 74 genes differentially expressed between the two clusters were defined as chondrogenesis-relevant genes. Gene expression profiles of chondrosarcoma were submitted to hierarchical clustering on the basis of these chondrogenesis-relevant genes. This analysis allowed clear distinction between grade I and grade III chondrosarcoma and separated grade II chondrosarcoma into two groups. All grade II chondrosarcomas with occurrence of metastasis were found together with the grade III chondrosarcomas in the pre-chondrogenic cluster."

The ages used for the mesenchymal stem cell samples ranged from 5-74.

"MSCs from eight donors were expanded and submitted to chondrogenic induction in spheroid culture in the presence of TGFβ3"

Genes upregulated during chondrogenic differentiation of MSC spheroids also upregulated during LSJL:

COL10A1

COL2A1

ACAN

H19

COL11A1

FXYD6

HAPLN1

ANGPTL2

MATN3

COL1A1

Osteopontin

BSP

LUM

SERPINA3{as SERPINA3N}

COL12A1

AEBP1

CSPG4

BGN

Acta2

Col3a1

Osteocalcin

41.1% of 51 genes.

Downregulated:

Igfbp6{up}

Timp1{up}

Ninj1

Col14a1{up}

The authors did provide the list of differentially regulated genes in chondrosarcoma but they said that the stages of chondrosarcoma differed based on fold expression of different genes.

Microarray analysis of gene expression in chondrosarcoma cells treated with bee venom.

"a human chondrocyte-like cell line treated with BV[Bee Venom], microarray analysis was performed.

The HTB-94 human chondrosarcoma cells were treated with BV, lipopolysaccharide (LPS), or both. Of the 344 genes profiled in this study, with a cut-off level of 4-fold change in the expression, (1) 35 were downregulated following BV treatment, (2) 16 were upregulated and 7 downregulated following LPS treatment, and (3) 32 were downregulated following co-stimulation of BV and LPS.

Treatment of BV reversed the LPS-induced upregulation of such genes as interleukin-6 (IL-6) receptor, matrix metalloproteinase 15 (MMP-15), tumor necrosis factor (ligand) superfamily-10, caspase-6 and tissue inhibitor of metalloproteinase-1 (TIMP-1)."

Bee venom has both pro- and anti- inflammatory effects.

"Cells were washed with the culture medium and incubated in the culture medium with the following agent(s) for 12 h: (1) vehicle or 10 ng/ml BV (Sigma, USA), (2) vehicle or 1 μg/ml Escherichia coli LPS, (3) 1 μg/ml LPS or 1 μg/ml LPS plus 10 ng/ml BV"

Genes downregulated in the human chondrosarcoma cell line treated with bee venom also downregulated by LSJL:

TIMP1{up}

TNFSF12{up}

TSC1

WISP2{up}

Genes upregulated by LPS treated human chondrosarcoma cell line also upregulated by LSJL:

TIMP1

Genes Downregulated:

Stk4

Genes downregulated in LPS + bee venom human chondrosarcoma treated cell lines also downregulated by LSJL:

CD33

CCNB1
THBS3{up}

"LPS is the major constituent of bacterial endotoxin and serves as an inflammatory agent against chondrocytes at such a concentration as 1 μg/ml"