The constitutive activation of STAT3 is generally recognized in clinical cases of liver cancer and in over 506 of human liver cancer cell lines but not in normal or low transformed human cells. Furthermore, FLLL32 was found to be efficient than other reported JAK2/STAT3 inhibitors, including FLLL32, WP1066, AG490, Stattic, selective c-Met inhibitor S3I 201, and curcumin inside our cancer cell lines. Conculsions Our results have shown that FLLL32 is an effective STAT3 inhibitor to inhibit STAT3 phophorlation, STAT3 DNA binding activity, STAT3 downstream target gene expression and induce apoptosis in human cancer cells from four independent cancer types including multiple myeloma, glioblastoma, colorectal and liver cancers. FLLL32 was stronger than curcumin and other reported JAK2/STAT3 inhibitors within the inhibition of cancer cell viability inside our evaluations. Our results suggest that FLLL32 is just a powerful therapeutic agent for multiple types of cancer cells expressing constitutive STAT3 signaling including multiple myeloma, glioblastoma, colorectal and liver cancer cells. Techniques Cell Culture Human colonrectal cancer Immune system cell lines, glioblastoma cell line, human hepatic cancer cell lines, human multiple myeloma cell line and human breast cancer cell lines were bought from the American Type Culture Collection. These cancer cell lines were cultured in DMEM or RPMI 1640 supplemented with 10 percent fetal bovine serum. Inhibitors FLLL32, a curcumin made STAT3 inhibitor, and WP1066, a Janus like kinase 2 inhibitor, were produced in Dr. Pui Kai Lis laboratory. S3I 201, JAK2 and STAT3 SH2 inhibitors Stattic inhibitor AG490 was purchased from Calbiochem. Curcumin was obtained from Sigma Aldrich Chemical Co.. Western blot analysis FLLL32 and curcumin were dissolved in DMSO. Cancer cells were treated with all the stated concentrations of the agencies or DMSO for twenty four hours, then lysed in cool RIPA lysis buffer containing protease inhibitors and subjected to SDS PAGE. The primary antibodies were purchased from Cell-signaling Technologies, including angiogenesis assay phospho specific STAT3, phospho specific STAT3, phospho specific JAK2, phospho specific STAT1, phospho specific ERK1/2, phospho specific mTOR, cleaved Poly polymerase, cleaved caspase 3, cyclin N, Bcl 2, survivin, TWIST1 and GAPDH. DNMT1 primary antibodies were obtained from abcam Inc. Membranes were scanned with a Storm PhosphorImager and examined with improved chemiluminescence Plus reagents. Kinase exercise analysis The possible ramifications of FLLL32 on five purified individual protein kinases were conducted at Reaction Biology Corp. using Kinase profiler analysis. The IC50 inhibitory values of FLLL32 to the kinase activity were established using 10 different concentrations of FLLL32 with 100 uM since the highest concentration.The cells were then left untreated or were treated with FLLL32, curcumin or DMSO for indicated hours.