Evaluating the Effectiveness of Cancer Drug Sensitization In Vitro and In Vivo

The overall goal of the following experiment is to evaluate the effectiveness of cancer drug sensitization by measuring changes in cell metabolism in vitro and metastatic frequency in vivo. This is achieved by first transecting cancer cells in vitro with antisense molecules to knock down the target of interest. Next, the transfected cells are plated onto biosensor chips and loaded into a metabolism measurement system to enumerate changes in acidification respiration and adhesion during drug treatment.

Separately, transfected cells are treated with a drug and injected into the venous circulation of a chicken embryo in order to evaluate effects on metastatic frequency. The results show cancer drug sensitization as illustrated by changes in cell metabolism and metastatic frequency. This technique extends the development of cancer therapy because it allows for the simultaneous evaluation of parameters that are not always considered during conventional preclinical testing of drug targets or compounds.

Though this method can provide insight into novel drug targets involved in DNA repair, it can also be applied to target validation in other systems such as cell cycle control. After transecting tumor cells with antisense oligonucleotides, according to the text protocol in a sterile environment, use 400 microliters of PBS to carefully wash six biosensor chips To sterilize the chips, remove the PBS and add 400 microliters of 70%ethanol incubate for 20 minutes before using PBS to wash the chips three times. Place three chips each into sterile culture dishes, labeled control and target of interest, and label two 50 milliliter tubes in a similar manner.

Next, use PBS to wash the transfected cells before adding an appropriate volume of 0.25%trypsin EDTA, wait until the monolayer detaches and transfer the cell suspension into the appropriate tube. After counting the cells, adjust the volume to reach a final concentration of 6.0 times 10 to the fifth cells per milliliter by either adding medium or concentrating the cells. Preparing one group at a time, add 250 microliters of cell solution to each biosensor chip.

Place the sterile dishes containing the chips inside a humidity chamber to prevent evaporation and incubate overnight to carry out metabolism measurements following the experimental outline detailed in the text protocol label 1450 milliliter tubes and add 50 milliliters of growth, medium plus 0.2%FBS and one x penicillin and streptomycin. Or PS.Place six tubes in one metabolism measurement system, tube rack six in another and the remaining tube in a third tube rack that also contains tubes with cisplatin. Use an air permeable membrane to seal the first two racks to prevent evaporation.

Next, prepare an appropriate volume of six micromolar cisplatin in medium with 0.2%FBS and one XPS. Dispense the required volume of medium into four labeled 50 milliliter tubes, and place them back into the four slots of the third metabolism measurement tube rack. Use air permeable membrane to seal the tubes.

Label six 50 milliliter tubes and add 20 milliliters to each of 0.1%Triton X solution In medium, the Triton X solution will lies any remaining cells and provide a zero value for each chip. Place the tubes in a fourth tube rack and seal them. Then load the chips into the bio modules.

Load the two bracks into the two brack holder, and then initiate the experiment. After preparing chicken embryos as referenced in the text protocol on day two of cell transfection, subdivide the control and target interest groups into two flasks for vehicle and two for cisplatin. Aspirate the medium and use either three milliliters of fresh, medium, or medium with six micromolar cisplatin to replenish.

The flasks incubate for six hours. After the incubation aspirate the medium, then wash and tryps anize the cells, transfer the cell suspension into four appropriately labeled 15 milliliter tubes before spinning and using PBS to wash three times Resus resuspend the cells. And then after counting, use PBS to dilute or centrifugation to concentrate the cells to a final concentration of 1.0 times 10 to the sixth cells per milliliter.

Transfer the cell suspension into five milliliter tubes labeled for injection and place on ice. Next, set aside 24 9 day old chicken embryos for injection under a stereo microscope and using a glass needle attached to a flexible tube connected to a one milliliter syringe with a slow pulsating motion. Inject 1.0 times 10 to the fifth cells in a volume of 100 microliters into the venous circulation of the choal toic membrane or cam with a soft wipe.

Gently dab the injection site to stem the flow of blood and absorb any spin spillage. Label each embryo container appropriately following each injection under a fluorescent microscope. Confirm the presence and distribution of fluorescent cells in the vasculature of the cam.

Take note of any embryos in which the number of tumor cells appears low or the distribution is poor. Finally, place the chicken embryos in a humidity chamber and incubate for seven to nine days before enumerating metastatic foci as outlined in the text protocol as shown here after 24 hours human, A 5 49 lung cancer cells treated with BRCA two targeting a SO and cisplatin exhibited an early and irreversible decrease in respiration compared to cells that received control a SO and cisplatin alone. The 39%decrease compared to the control treated cells began approximately 10 hours before a detectable drop in cell adhesion, suggesting that it occurred independently of changes in cell number and that it may be a formative event that precedes cell death as demonstrated here.

No difference in acidification was observed during the 72 hour experiment suggesting that BRCA two a SO and cisplatin treatment had little to no effect on glucose metabolism. In this experiment, human A 5 49 lung cancer cells were treated with control a SO or BRCA two A SO in the presence or absence of cisplatin and injected into the venous circulation of the cam. Nine days later, cells treated with BRCA two a SO and cisplatin exhibited a 77%lower frequency of metastatic foci compared to cells treated with control a SO and cisplatin or BRCA two A SSO alone suggesting that BRCA two a SO and cisplatin treatment has the potential to decrease or prevent metastatic burden in patients with solid tumors.

Following this procedure, more traditional methods such as cell proliferation, assays and in vivo xenograft studies can be performed in order to further explore the contribution of a particular target to enhanced drug sensitivity.