Method for determining a biological pathway activity

A method for in vitro establishing a prognosis to develop a pathology for an healthy individual, by determining a level of activity of a biological pathway, said method comprising the steps of:

• providing a sample from the healthy individual,
• measuring the level of expression of at least three genes from a group of individuals, control individuals or patients suffering from the pathology, for which the biological pathway is inactive, said at least three genes being associated to said biological pathway, for establishing a negative reference, and
• measuring level of expression of said at least three genes from a group of individuals, control individuals or patients suffering from the pathology, for which the biological pathway is active, for establishing a positive reference, and
• measuring the level of expression of said at least three genes of said healthy individual in the sample, and
• comparing the level of expression of said at least three genes in the sample of said healthy individual with the level of expression of said at least three genes of the negative reference and determining a value C− which corresponds to a correlation level between the level of expression of said at least three genes of said negative reference and the level of expression of said at least three genes of said control individual, and
• comparing the level of expression of said at least three genes in the sample of said healthy individual with the level of expression of said at least three genes of the positive reference and determining a value C+ which corresponds to a correlation level between the level of expression of said at least three genes of said positive reference and the level of expression of said at least three genes of said control individual, and
• establishing a ratio 0+/C− which gives a correlation score, wherein
• if the correlation score is lower to 1 that is indicative of the non activity of the biological pathway, that means that the healthy individual could not develop the pathology, and
• if the correlation score is upper or equal to 1 that is indicative of the activity of the biological pathway, that means that the healthy individual could develop the pathology.

A method for in vitro establishing a diagnosis of a pathology for a patient, by determining a level of activity of a biological pathway, said method comprising the steps of:

• providing a sample from the patient,
• measuring the level of expression of at least three genes from a group of individuals, control individuals or patients suffering from the pathology, for which the biological pathway is inactive, said at least three genes being associated to said biological pathway, for establishing a negative reference, and
• measuring level of expression of said at least three genes from a group of individuals, control individuals or patients suffering from the pathology, for which the biological pathway is active, for establishing a positive reference, and
• measuring the level of expression of said at least three genes of said patient in the sample, and
• comparing the level of expression of said at least three genes in the sample of said patient with the level of expression of said at least three genes of the negative reference and determining a value C− which corresponds to a correlation level between the level of expression of said at least three genes of said negative reference and the level of expression of said at least three genes of said patient, and
• comparing the level of expression of said at least three genes in the sample of said patient with the level of expression of said at least three genes of the positive reference and determining a value C+ which corresponds to a correlation level between the level of expression of said at least three genes of said positive reference and the level of expression of said at least three genes of said patient, and
• establishing a ratio 0+/C− which gives a correlation score, wherein
• if the correlation score is lower to 1 that is indicative of the non activity of the biological pathway, that means that the patient does not suffer from the pathology associated with the activity of the biological pathway, and
• if the correlation score is upper or equal to 1 that is indicative of the activity of the biological pathway, that means that the patient suffers from the pathology associated with the activity of the biological pathway.

A method for assessing whether a patient having a pathology is in need of a drug administration, said drug interacting directly or indirectly with a biological pathway, in which the biological activity of the biological pathway is determined and said biological activity is associated with said pathology, said method comprising the steps of:

• providing a sample from the patient,
• measuring the level of expression of at least three genes from a group of individuals, control individuals or patients, for which the biological pathway is inactive, said at least three genes being associated to said biological pathway, for establishing a negative reference, and
• measuring level of expression of said at least three genes from a group of individuals, control individuals or patients, for which the biological pathway is active, for establishing a positive reference, and
• measuring the level of expression of said at least three genes of said patient in the sample, and
• comparing the level of expression of said at least three genes in the sample of said patient with the level of expression of said at least three genes of the negative reference and determining a value C− which corresponds to a correlation level between the level of expression of said at least three genes of said negative reference and the level of expression of said at least three genes of said patient, and
• comparing the level of expression of said at least three genes in the sample of said patient with the level of expression of said at least three genes of the positive reference and determining a value C+ which corresponds to a correlation level between the level of expression of said at least three genes of said positive reference and the level of expression of said at least three genes of said patient, and
• establishing a ratio 0+/C− which gives a correlation score, wherein
• if the correlation score is lower to 1 that is indicative of the non activity of the biological pathway, that means that the patient needs administration of the drug, and
• if the correlation score is upper or equal to 1 that is indicative of the activity of the biological pathway, that means that the patient does not need administration of the drug.

A method for monitoring the treatment response of a patient to the administration of a drug, said drug interacting directly or indirectly with a biological pathway, in which the biological activity of the biological pathway is determined and said biological activity is associated with a pathology, said method comprising the steps of:

• providing a sample from the patient,
• measuring the level of expression of at least three genes from a group of individuals, control individuals or patients, for which the biological pathway is inactive, said at least three genes being associated to said biological pathway, for establishing a negative reference, and
• measuring level of expression of said at least three genes from a group of individuals, control individuals or patients, for which the biological pathway is active, for establishing a positive reference, and
• measuring the level of expression of said at least three genes of said patient in the sample, and
• comparing the level of expression of said at least three genes in the sample of said patient with the level of expression of said at least three genes of the negative reference and determining a value C− which corresponds to a correlation level between the level of expression of said at least three genes of said negative reference and the level of expression of said at least three genes of said patient, and
• comparing the level of expression of said at least three genes in the sample of said patient with the level of expression of said at least three genes of the positive reference and determining a value C+ which corresponds to a correlation level between the level of expression of said at least three genes of said positive reference and the level of expression of said at least three genes of said patient, and
• establishing a ratio 0+/C− which gives a correlation score, wherein
• if the correlation score is lower to 1 that is indicative of the non activity of the biological pathway, that means that the patient is a bad responder to the drug, and
• if the correlation score is upper or equal to 1 that is indicative of the activity of the biological pathway, that means that the patient is a good responder to the drug.