Prognostic implications of Kindlin proteins in human osteosarcoma

Abstract

The Kindlin protein family, comprising Kindlin-1, Kindlin-2 and Kindlin-3, play important roles in various human cancers. Here, to explore the clinical significance of Kindlins in human osteosarcomas, quantitative real-time PCR and Western blot analyses were performed to detect the expression of Kindlin-1, Kindlin-2 and Kindlin-3 mRNAs and proteins in 20 self-pairs of osteosarcoma and adjacent noncancerous tissues. Then, immunohistochemistry was performed to examine subcellular localizations and expression patterns of Kindlin proteins in 100 osteosarcoma and matched adjacent noncancerous tissues. Kindlin-1, Kindlin-2 and Kindlin-3 protein immunostainings were localized in the cytoplasm, nucleus and cytoplasm, respectively, of tumor cells in primary osteosarcoma tissues. Statistically, the expression levels of Kindlin-1 and Kindlin-2 mRNAs and proteins in osteosarcoma tissues were all significantly higher (both P<0.01), but those of Kindlin-3 mRNA and protein were both dramatically lower (both P<0.05), than in matched adjacent noncancerous tissues. In addition, the overexpressions of Kindlin-1 and Kindlin-2 proteins were both significantly associated with high tumor grade (both P=0.01), presence of metastasis (both P=0.006), recurrence (both P=0.006) and poor response to chemotherapy (both P=0.02). Moreover, Kindlin-1 and Kindlin-2 expressions were both identified as independent prognostic factors for overall (both P=0.01) and disease-free (P=0.02 and 0.01, respectively) survivals of osteosarcoma patients. However, no associations were observed between Kindlin-3 expression and various clinicopathologic features and patients’ prognosis. In conclusion, aberrant expression of Kindlin-1 and Kindlin-2 may function as reliable markers for progression and prognosis in osteosarcoma patients, especially for tumor recurrence.

Distinct expression profiles and functions of Kindlins in breast cancer

“…Many tumor types concomitantly express more than one member of the Kindlin family. In osteosarcomas, Kindlin-1 and -2 up-regulation was associated with a higher tumor grade and a poor prognosis [ 27 ], whereas they were found differentially expressed in lung and esophageal cancers where they might oppositely regulate cancer progression [ 28 , 29 ]. The question of the involvement of the three Kindlins in breast tumors has never been addressed; whether they have redundant and/or complementary roles in mammary tumors remains largely unknown.…”

Expression of microRNA-150 and its Target Gene IGF2BP1 in Human Osteosarcoma and their Clinical Implications

“…The clinicopathologic characteristics of the osteosarcoma patients were listed in Table 1 . The detailed information of the two clinical cohorts used in the present study was provided in our previous publication [ 17 ].…”

“…The expression levels of miR-150 and IGF2BP1 mRNA in ostoesarcoma and adjacent noncancerous tissues were detected by quantitative real-time PCR according to the protocol of our previous study [ 17 ]. The primer sequences used in this study were listed as follows: for miR-150, Forward Primer 5'- GCT CTC CCA ACC CTT GTA CC - 3', Reverse Primer 5'- CGA GGA AGA AGA CGG AAG AAT - 3'; for U6, Forward Primer 5'- GCT TCG GCA GCA CAT ATA CTA AAA T -3', Reverse Primer 5'- CGC TTC ACG AAT TTG CGT GTC AT -3'; for IGF2BP1, Forward Primer 5'- CAG GAG ATG GTG CAG GTG TTT ATC C - 3', Reverse Primer 5'- GTT TGC CAT AGA TTC TTC CCT GAG C - 3'; for GAPDH, Forward Primer 5'- AAT CCC ATC ACC ATC TTC CA -3', Reverse Primer 5'- TGG ACT CCA CGA CGT ACT CA -3'.…”

“…The expression levels of IGF2BP1 protein in osteosarcoma and adjacent noncancerous tissues were detected by Western blot analysis according to the protocol of our previous study [ 17 ]. The following primary antibodies were used: IGF2BP1 protein (rabbit polyclonal antibody, Abcam, MA, USA; 1:150 dilution) and GAPDH (rabbit polyclonal antibody, Abcam, MA, USA; 1:150 dilution).…”

“…Subcellular localization and expression pattern of IGF2BP1 protein in osteosarcoma tissues were examined by immunohistochemistry was performed according to the protocol of our previous study [ 17 ]. The following primary antibody was used: IGF2BP1 protein (rabbit polyclonal antibody, Abcam, MA, USA; 1:150 dilution).…”