Lung cancer detection method and detection kit

Abstract

Lung cancer can be detected by measuring sites in pancreatic ribonuclease 1 (also abbreviated as “RNase 1”), wherein each of the sites is a site capable of being modified with an N-linked sugar chain. Lung cancer is detected by measuring items A and B as mentioned below and then comparing the ratio of the value of A to the value of B: A=the amount of sites in pancreatic ribonuclease 1, wherein the sites are sites each capable of being modified with an N-linked sugar chain and each having an N-linked sugar chain bound thereto or each having an N-linked sugar chain unbound thereto; and B=the amount of sites in pancreatic ribonuclease 1, wherein the sites are sites each capable of being modified with an N-linked sugar chain.

Claims

1. A method for detecting and treating lung cancer in a subject, comprising: measuring the amount of a putative N-glycosylation site of pancreatic ribonuclease 1 linked with an N-glycan chain or not linked with an N-glycan chain using an immunological method in a subject suspected of having lung cancer, diagnosing the subject with lung cancer if the amount of the site linked with the N-glycan chain is increased in comparison with healthy individuals, and treating the subject with lung cancer with a method for the treatment of lung cancer, wherein the putative N-glycosylation site is asparagine residue at position 88 of the sequence indicated in SEQ ID NO: 1.

2. A method for detecting and treating lung cancer in a subject, comprising: determining the ratio of the value of A to the value of B for A and B indicated below: A: amount of putative N-glycosylation site of pancreatic ribonuclease 1 linked with an N-glycan chain or not linked with an N-glycan chain measured using an immunological method in a subject suspected of having lung cancer; and, B: amount of putative N-glycosylation site of pancreatic ribonuclease 1 measured using an immunological method in a subject suspected of having lung cancer, diagnosing the subject with lung cancer if the value of A/B is smaller in comparison with healthy individuals when A represents the amount of the site not linked with an N-glycan chain or if the value of A/B is larger in comparison with healthy individuals when A represents the amount of the site linked with an N-glycan chain, and treating the subject with lung cancer with a method for the treatment of lung cancer, wherein the putative N-glycosylation site is asparagine residue at position 88 of the sequence indicated in SEQ ID NO: 1.

3. The method according to claim 2, wherein the amount of pancreatic ribonuclease 1 is determined and that value is converted to use as the value of B.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a graph illustrating the distributions of G3/t ratios of healthy individuals and patients with lung cancer, wherein the dashed line represents a cut-off value, 0.184.

(2) FIG. 2 is a drawing illustrating the results of total RNase 1 amounts in extracts from normal human tissue.

(3) FIG. 3 is a drawing illustrating the distributions of G3/t ratios of tissue types of lung cancer, wherein the dashed line represents a cut-off value, 0.184.

EXAMPLES

Example 1: Amount of Asn88 at which an N-Glycan Chain is Linked, Amount of Asn88, and Ratio Thereof in Serum Samples Derived from Patients with Lung Cancer

(4) The putative N-glycosylation site to be measured was designated Asn88. The amount of Asn88 at which an N-glycan chain is linked (G3), and the amount of Asn88 (t) were measured using the immunological assay reagents and the assay described in Examples 3 and 4 of Patent Document 2, respectively. Thirty-five serum samples obtained from healthy individuals and 40 serum samples obtained from patients with lung cancer were measured using the above immunological assay reagents. In this Example, the amount of the putative N-glycosylation site Asn 88 can be calculated as a value which is one time the total amount of RNase 1. The results are shown in Table 1 and FIG. 1.

(5) TABLE-US-00001 TABLE 1 Healthy Patients with individuals lung cancer (average and (average and distribution distribution range) range) P value Number of samples 35 40 Age Distribution 38 69 (27 to 62) (48 to 78) Amount (t) of   256.09   250.95 0.54 Asn88 (151.91 to 369.48) (122.12 to 846.88) Amount (G3) of   29.44   93.02 <0.05 Asn88 at which  (16.1 to 48.13)  (49.49 to 259.49) an N-glycan chain is linked G3/t ratio    0.11   0.3 <0.05 (0.1 to 0.13) (0.24 to 0.6) 

(6) As shown in Table 1 and FIG. 1, both of the G3 and the G3/t ratio of the lung cancer patient serum were significantly higher than those of healthy individual group (p<0.05 in both cases). These results demonstrated that lung cancer can be detected by measuring G3 or the G3/t ratio.

Example 2: Verification of the Expression of RNase 1 in Normal Human Lung Tissue

(7) Homogenates of normal human lung tissue, tissue extracts of normal human pancreatic tissue, tissue extracts of normal human stomach tissue were obtained from BioChain, Inc. The total RNase 1 amounts of these extracts were measured by the above immunological assay. As illustrated in FIG. 2, the expression of RNase 1 was verified even in normal human lung tissue. Thus, the reason that the cancerous change of lung tissue changed the level of the linkage of N-glycan chain at Asn88 of RNase 1 in the bloodstream was considered to be the enhancement of the linkage of N-glycan chain at Asn88 during the novel biosynthetic process of RNase 1 expressed in lung cancer cells.

Example 3: Analysis of the Distributions of G3/t Ratios of Tissue Types of Lung Cancer

(8) The 40 serum samples (which were able to be histologically diagnosed) obtained from patients with lung cancer were measured using the immunological assay reagents and the assay described in Example 1. The results are plotted for each tissue type in FIG. 3. As is clear from FIG. 3, all of the ratios of each of the four tissue types exceeded the cut-off value 0.184. These results in combination with the results illustrated in FIG. 1 demonstrated that all of the four types of lung cancer were uniformly detected without a deviation in the four tissue types using the above mentioned immunological assay reagents and the assay, and thus, suggested that the immunological assay reagents and the assay are excellent in the detection of a wide variety of types of lung cancer.

(9) The contents of the specification, sequence listing, claims, drawings, and abstract of the Japanese Patent Application No. 2016-099312 filed on May 18, 2016 are incorporated herein by reference as if fully set forth in their entireties.