Ok, I'll use PBS instead of culture medium. Thanks for your quick answer!

Here we inject 100ul of 2x10e6 cells/ml in PBS, near but not in the nipple w/o problem.

Good luck.

You do not need matrigel to generate tumors in MG but the efficiency would be much better. For example, if you need 10^4 cells to get tumors with matrigel, you will need 10^6 or 10^7 cells wothoutmatrigel. It alldepends what you want to look into.

Thank you all!

I agree with Dr. Frey. What we have noted is that low-passage MCF7 cells do not need Matrigel, but that at higher passages, Matrigel improves engraftment efficiency.

We observed using 4T1 cells for orthotopic implantation that they give rise only to metastases if they are injected with Matrigel but not if injected with medium/PBS. This is also the case for other bc cell lines. So if you want to look at vascularization of pt it works without, but mets might not work.

We have implanted MCF-7 in the mammary fat pad and as xenografts without using Matrigel. The tumors develop as expected. We have also used medium or PBS with no difference in outcome.

Hi, You can inject MCF-7 with out mixing with matrigel , it will form tumor when you resupend the cells in either DMEM or HBSS ( hanks media). Remember the MCF-7 is eastrogen dependant cell lines. It is better if you implant eastrogen pellet s.c in mice just 3 days before the injection of MCF-7 cells. Good luck

Suresh

We have injected MCF7 cells via mammary intraductal injection without matrigel, resuspended in PBS. However, as mentioned by Suresh, they are estrogen dependent. We implanted an estrogen pellet s.c. same day of cell injection and tumors developed.

In my opinion, I do not think Matrigel is nessary for the modle construction.

we have injected the MCF-7 cells to the mice by suspending in PBS and that worked well. You can also try that. Matrigel is no needed i think.

As per my experience matrigel is not at all essential for tumorigenicity but it increases the pick up rate,uniformity and growth rate of tumors as it gives support in angiogenesis. i tried MCF-7 with matrigel and serum free medium in 1:1 ratio (0.2ml), one day prior implantion of eastrogen pellet s.c on the other side in mice that worked well.

Good luck.

Milind...

Thank you, Milind! I've tried last month MCF-7 without matrigel, but also without estrogen pellet, and it did not work. I suppose because I didn't use estrogen pellet.

Best for 2013!

Milind, I'll try as you did it next time!

Hi everyone! Very good question u got there. I've tried with 1 x 10^6 MCF-7 in PBS without matrigel and without estrogen.. 3 weeks have gone and no tumour yet. Anyone knows how long it would take to develop in this kind of setting?

Hello Muhd sufyan...MCF-7 is an estrogen dependent cell line,so it requires a sufficient amount of estrogen level maintained in Nude mouse for a proper tumor take up and growth.if it is not so then estrogen should be given externally....Earlier i had tried without estrogen pellet and didnot observed tumor even after 60 days of cell inoculation..i would suggest you to try with estrogen in a proper way as i have written in my previous answer above for proper tumor growth..

best luck...

Hello Milind Sagar

i can't find proper way as you have written in your previous answer?

Hello vahid fattahi..what is your doubt/confusion?

Please ask clearly, i'll try my best to explain you.

Thanks,

milind

Adding Matrigel is crucial - this will drastically improve the growth rate (and take rate) and this is important since E2 pellets are can cause bladder distention (calcification) after ~6 weeks and force unnecessary culls

Agree with Milind. But it is also important to note that usage of Estrogen pellets for ~ 5- 6 weeks will result in toxicity - most commonly urinary bladder retention. Also we have observed pruritus and ulcerative dermatitis in the perineum region of some of the animals. For more information, please refer this article: Vet Pathol 46:505–508 (2009) and/or Toxicol Pathol 2009 37: 227

Thank you, Kiran!

Dear you can use normal RPMI or PBS for keeping the MCF-7 for few minutes before injection, but Matrigel gives better result. TQ

Hello Manuel. Although you can get a tumor without using Matrigel, you will not get a tumor in nude mice without using estrogen pellets as stated before. However, using Matrigel will give you much better results. You'll get bigger tumors and they'll develop faster. Be sure to mix the MCF-7 cells and Matrigel right before injection. I found that this helped with getting a higher percentage of tumors. Also, make sure your cells are grown to 70% in the culture dish. Any more and you run the risk of injecting too many dead cells into the mammary fat pads. I hope this helps you.

Thank you, Latonya!

I would use Matrigel (50:50) with E2 pellet supplement

Please also note that with E2 supplement, in Nude mice, there is a condition that the mice develop called Haggis Bladder. With prolonged use of E2 supplement, the bladder of Nude mice form crystals. These crystals grow until they block the urethra. It can also cause genital ulceration. You can express the urine daily, up to a certain point, in which Nude mice, have to be sacrificed, under British Home Office Licensing. Not sure the limitations in your country.

Also if you decide to do this, ensure you implant the E2 pellet, at least 2-3 days before injecting cells.

We do not work with MCF7 in Nude mice, because of this problem.