A Murine Orthotopic Bladder Tumor Model and Tumor Detection System

Summary

This protocol describes the generation of murine orthotopic bladder tumors in female C57BL/6J mice and the monitoring of tumor growth.

Abstract

This protocol describes the generation of bladder tumors in female C57BL/6J mice using the murine bladder cancer cell line MB49, which has been modified to secrete human Prostate Specific Antigen (PSA), and the procedure for the confirmation of tumor implantation. In brief, mice are anesthetized using injectable drugs and are made to lay in the dorsal position. Urine is vacated from the bladder and 50 µL of poly-L-lysine (PLL) is slowly instilled at a rate of 10 µL/20 s using a 24 G IV catheter. It is left in the bladder for 20 min by stoppering the catheter. The catheter is removed and PLL is vacated by gentle pressure on the bladder. This is followed by instillation of the murine bladder cancer cell line (1 x 10⁵ cells/50 µL) at a rate of 10 µL/20 s. The catheter is stoppered to prevent premature evacuation. After 1 h, the mice are revived with a reversal drug, and the bladder is vacated. The slow instillation rate is important, as it reduces vesico-ureteral reflux, which can cause tumors to occur in the upper urinary tract and in the kidneys. The cell line should be well re-suspended to reduce clumping of cells, as this can lead to uneven tumor sizes after implantation.

This technique induces tumors with high efficiency. Tumor growth is monitored by urinary PSA secretion. PSA marker monitoring is more reliable than ultrasound or fluorescence imaging for the detection of the presence of tumors in the bladder. Tumors in mice generally reach a maximum size that negatively impacts health by about 3 - 4 weeks if left untreated. By monitoring tumor growth, it is possible to differentiate mice that were cured from those that were not successfully implanted with tumors. With only end-point analysis, the latter may be mistakenly assumed to have been cured by therapy.

Introduction

The goal of this method is to generate murine orthotopic bladder tumors and to monitor the implanted tumors as accurately as possible, so that mice without tumor implantation are not thought to have been cured at end-point analysis. Overall, the method shown will reduce the need for large numbers of mice for experimental analysis and ensure greater accuracy in determining therapeutic outcomes.

The development of an orthotopic model for cancer is important, as implanting tumor cells subcutaneously does not recapitulate the environment of the clinical disease or enable the development of therapeutic strategies. The architecture of the bladder....

Protocol

All animal work adhered to the Institutional Animal Care and Use Committee (IACUC) guidelines on animal use and handling (Protocol number 084/12) at the National University of Singapore.

1. Growing MB49-PSA Cells In Vitro and Measuring PSA Secretion

1. Maintain murine bladder cancer cells MB49-PSA¹⁵ in complete Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 2 mmol/L L-glutamine, and 0.05 mg/mL Penicillin-Strepto.......

Discussion

The most critical steps in the protocol are 1) successfully maintaining the tumorigenicity of the cell line; 2) ensuring measurable PSA secretion before tumor cell implantation in mice; 3) generating a single-cell suspension for implantation so as to reduce variation in tumor size; and 4) instilling cells at a slow rate to prevent vesico-ureteral reflux, resulting in tumor cell implantation in the kidney.

After prolonged passage in vitro, MB49/MB49-PSA cells can lose their tumorigenic.......

Materials

Name	Company	Catalog Number	Comments
MB49-PSA cells	N/A	N/A	ref (Wu QH, 2004)
RPMI 1640 media	HyClone	SH30027.01
Dulbecco's Modified Eagle's Medium (DMEM) media	Biowest	L0102
Fetal Bovine Serum (FBS) South American	Biowest	S1810
Fetal Bovine Serum (FBS) South American, Premium	Biowest	S181B
Fetal Bovine Serum (FBS)	HyClone	SH30088.03
L-glutamine	Biowest	X0550
Penicillin-Streptomycin	Biowest	L0022
Hygromycin B	Invitrogen	10687-010
free PSA (Human) ELISA kit	Abnova	KA0209
TRIzol Reagent for RNA extraction	Ambion	15596026
High Capacity cDNA Reverse Transcription Kit with RNase Inhibitor	Applied Biosystems	4374967
TaqMan Universal PCR Master Mix	Applied Biosystems	4304437
TaqMan Gene Expression Assay – Mouse Actb	Applied Biosystems	4331182	Mm00607939_s1
TaqMan Gene Expression Assay – Human KLK3	Applied Biosystems	4331182	Hs00426859_g1
C57BL/6J female mice	In Vivos		4-6 wk old
Anesthesia (75mg/kg Ketamine and 1mg/kg Medetomidine)	Local pharmacy
Reversal drug (1mg/kg Atipamezole)	Local pharmacy
Ear punch	Electron Microscopy Sciences	72893-01
Hartmann's solution or Compound sodium lactate	B Braun
Ophthalmic ointment - Duratears sterile ocular lubricant ointment	Alcon
Heat pack - HotHands handwarmers	Heatmax Inc
Introcan Certo IV catheter	B Braun	4251300	24G x 3/4″
Aquagel Lubricating jelly	Local pharmacy
Poly-L-lysine solution, 0.01%,	Sigma	P4707
cOmplete, Mini, EDTA-free Protease Inhibitor Cocktail	Roche	4693159001
Quantichrom Creatinine Assay Kit	BioAssay Systems	DICT-50
Fluorescent dye - VivoTrack 680	Perkin Elmer	NEV12000
RNAlater-ICE Frozen Tissue Transition Solution	Ambion	4427575
Name	Company	Catalog number	Comments
Equipment and Software
7500 Realtime PCR System	Applied Biosystems
7500 Software v2.3	Applied Biosystems
Metabolic Cage	Tecniplast	Vertical type rack for 12 cages
BD FACSCanto I system	BD Biosciences
BD FACSDiva software v7	BD Biosciences
IVIS SpectrumCT in vivo imaging system	Caliper Life Sciences
Living Image Software v3.1	Caliper Life Sciences
Vevo 2100 imaging system	VisualSonics