# US 11,111,547 B2 · Tumor suppressor REC8 as a biomarker for gastric cancer

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- Number: US 11,111,547 B2
- Document ID: US11111547B2
- Status: Granted
- Kind: B2
- Application number: 16/443,621
- Filed: 2019-06-17
- Published: 2020-01-23
- Granted: 2021-09-07
- Earliest claimed: 2017-05-19
- Assignees: The Chinese University of Hong Kong
- Applicants: The Chinese University of Hong Kong
- Inventors: Jun Yu; Joseph Jao Yiu Sung; Qiaoyi Liang
- Web page: https://patentgrep.com/patent/US11111547B2

## CPC

- C12Q 1/6886: for cancer (immunoassay for cancer G01N33/575)
- A61K 38/1709: {from mammals}
- G01N 33/5753: of the stomach or small intestine
- G01N 33/6875: {Nucleoproteins}
- C12Q 2600/118: Prognosis of disease development
- C12Q 2600/154: Methylation markers
- C12Q 2600/158: Expression markers
- G01N 2800/50: Determining the risk of developing a disease
- C12Q: MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS (immunoassay G01N33/53); COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

The present invention provides a method for diagnosing and determining prognosis of gastric cancer in a subject by detecting suppressed expression of the REC8 gene, which in some cases is due to elevated methylation level in the genomic sequence of this gene. A kit and device useful for such a method are also provided. In addition, the present invention provides a method for treating gastric cancer by increasing REC8 gene expression or activity. Lastly, a highly sensitive and accurate detection method is provided for rapid determination of REC8 gene methylation status.

## Claims

### Claim 1

A method for reducing risk for gastric cancer in a subject, comprising the steps of:
(a) treating DNA from a sample taken from the subject with an agent that differentially modifies methylated and unmethylated DNA, wherein the sample is a stomach mucosa sample or a plasma or serum sample;
(b) determining the number of methylated CpGs in a genomic sequence, which is SEQ ID NO:5 or a fragment thereof comprising at least 5 CpGs; and
(c) comparing the number of methylated CpGs from step (b) with the number of methylated CpGs in the genomic sequence from a non-cancer sample of the same type and processed through steps (a) and (b);
(d) determining the subject, whose sample contains more methylated CpGs in the genomic sequence determined in step (b) compared to the number of methylated CpGs in the genomic sequence from the non-cancer sample of the same type and processed through steps (a) to (b), as having an increased risk for gastric cancer compared with a healthy subject not diagnosed with gastric cancer; and
(e) subjecting the subject who is determined in step (d) as having an increased risk for gastric cancer to (i) reduction or elimination of consumption of foods preserved by drying, smoking, salting, or pickling; (ii) regular screening/examination by endoscopy; or (iii) testing for infection by Helicobacter pylori.

### Claim 2 (depends on 1)

The method of claim 1, wherein the genomic sequence is SEQ ID NO:5 or a fragment of SEQ ID NO:5 comprising at least 10 CpGs.

### Claim 3 (depends on 1)

The method of claim 1, wherein the genomic sequence is SEQ ID NO:5 or a fragment of SEQ ID NO:5 comprising at least 15 CpGs.

### Claim 4 (depends on 1)

The method of claim 1, wherein the agent that differentially modifies methylated DNA and unmethylated DNA is an enzyme that preferentially cleaves methylated DNA, an enzyme that preferentially cleaves unmethylated DNA, or a bisulfite.

### Claim 5 (depends on 1)

The method of claim 1, wherein step (b) comprises an amplification reaction.

### Claim 6 (depends on 1)

The method of claim 1, wherein the sample is a stomach mucosa sample.

### Claim 7 (depends on 1)

The method of claim 1, wherein the sample is a plasma or serum sample.