Published online Nov 21, 2018. doi: 10.3748/wjg.v24.i43.4880
Peer-review started: August 3, 2018
First decision: October 8, 2018
Revised: October 22, 2018
Accepted: November 2, 2018
Article in press: November 2, 2018
Published online: November 21, 2018
Processing time: 110 Days and 14.1 Hours
To establish patient-individual tumor models of rectal cancer for analyses of novel biomarkers, individual response prediction and individual therapy regimens.
Establishment of cell lines was conducted by direct in vitro culturing and in vivo xenografting with subsequent in vitro culturing. Cell lines were in-depth characterized concerning morphological features, invasive and migratory behavior, phenotype, molecular profile including mutational analysis, protein expression, and confirmation of origin by DNA fingerprint. Assessment of chemosensitivity towards an extensive range of current chemotherapeutic drugs and of radiosensitivity was performed including analysis of a combined radio- and chemotherapeutic treatment. In addition, glucose metabolism was assessed with 18F-fluorodeoxyglucose (FDG) and proliferation with 18F-fluorothymidine.
We describe the establishment of ultra-low passage rectal cancer cell lines of three patients suffering from rectal cancer. Two cell lines (HROC126, HROC284Met) were established directly from tumor specimens while HROC239 T0 M1 was established subsequent to xenografting of the tumor. Molecular analysis classified all three cell lines as CIMP-0/ non-MSI-H (sporadic standard) type. Mutational analysis revealed following mutational profiles: HROC126: APCwt, TP53wt, KRASwt, BRAFwt, PTENwt; HROC239 T0 M1: APCmut, P53wt, KRASmut, BRAFwt, PTENmut and HROC284Met: APCwt, P53mut, KRASmut, BRAFwt, PTENmut. All cell lines could be characterized as epithelial (EpCAM+) tumor cells with equivalent morphologic features and comparable growth kinetics. The cell lines displayed a heterogeneous response toward chemotherapy, radiotherapy and their combined application. HROC126 showed a highly radio-resistant phenotype and HROC284Met was more susceptible to a combined radiochemotherapy than HROC126 and HROC239 T0 M1. Analysis of 18F-FDG uptake displayed a markedly reduced FDG uptake of all three cell lines after combined radiochemotherapy.
These newly established and in-depth characterized ultra-low passage rectal cancer cell lines provide a useful instrument for analysis of biological characteristics of rectal cancer.
Core tip: Ultra-low passage and in-depth characterized tumor models are highly desirable for basic research and assessment of individual response prediction to current or novel therapy regimens. Here, for the first time, we describe three patient-derived rectal cancer cell lines established either directly from patient’s tumor samples or after xenografting. These tumor models were characterized according to phenotype, molecular-, as well as growth and morphological features and sensitivity to chemotherapeutic drugs and radiation, including radiochemotherapy. In addition, glucose metabolism was assessed with 18F-fluorodeoxyglucose and proliferation with 18F-fluorothymidine. These cell lines provide excellent tools for basic and translational research of rectal cancers’ biological characteristics.