If there is a amplification in NTC, than most probably there could be contamination or mislabelling. you could try once by making fresh aliquots of all primers and samples.

Questions:

1) do these primers usually work (have you validated them for this assay, these conditions, etc etc)?

2) if so, what Cq values do you usually get?

3) do you see any amplicon at all? For example, have you run the samples on a gel after the PCR?

4) do you QC your RNA? If so, please post typical 260/230 ratios and approximate yields.

5) how much RNA do you use for cDNA synthesis, and do you use random priming, oligodT or both?

6) how much cDNA do you use per well in your qPCR?

7) what do you mean by "0,1uM and 0,2uM"?

8) are your cells green via fluorescence microscopy?

9) do you have a positive and negative control?

Amplification in your NTC with that strong of a signal is contamination.

Run out the products on a gel just to double-check, but I'd bet good money that you have the same size amplicons in your NTC as your positive control.

The only way to fix this is to eliminate the contamination. Common source is your micropipettes. Clean them & your work station. Get all new reagents (unopened bottles or make from scratch) for EVERYTHING (water, buffer, primers from a new dry stock, etc.).

Good luck!