CART Therapy in GUCY2C-positive Digestive Tract Tumors

Inclusion Criteria: 1\. Aged between 18 and 70; 2. Positive expression of immunohistochemical (IHC) assay targets in a laboratory approved by the partner; 3. Pathology confirmed digestive tract tumor; 4. Patients who have failed or relapsed after at least the first and second line standard treatment, and patients who are intolerant to or voluntarily give up the standardized treatment; 5. At least one extracranial measurable lesion according to RECIST1.1 or EORTC or PERCIST; 6. Expected survival ≥90 days; 7. The main organs are functioning normally, i.e. they meet the following criteria: 1. ECOG physical condition score is 0\~1 or KPS score is \>70; 2. serum test criteria were as follows: HB≥90g/L (no blood transfusion within 14 days), ANC≥ 1.5 x 10\^9/L, PLT≥80 x 10\^9/L, Alb ≥ 2.8g/dL, serum lipase and amylase \< 1.5×ULN (upper limit of normal value). 3. Biochemical examination shall meet the following standards: TBIL≤ 1.5x ULN (upper limit of normal value); ALT and AST≤ 2.5x ULN; ALT and AST≤5xULN in case of liver metastasis; Serum Cr≤1xULN, endogenous creatinine clearance rate \>50 ml/min (Cockcroft-Gault formula); 4. cardiac ejection fraction \>55%; 8. No hemorrhagic disease or coagulation disorder; 9. No allergy to the developer; 10. Women of childbearing age must undergo a pregnancy test (serum or urine) within 7 days prior to enrollment, with negative results, and be willing to use an appropriate method of contraception during and 8 weeks after the last dose of CART (women who have undergone sterilization or have been postmenopausal for at least 2 years may be considered sterile); 11. The subjects voluntarily joined the study, signed the informed consent form, had good compliance and cooperated with the follow-up. Exclusion Criteria: 1. T cell transduction efficiency \<5% or T cell amplification \< 2 times after culture; 2. Participated in other drug clinical trials within 4 weeks before the start of the study; 3. Patients with hypertension and unable to obtain good control by single antihypertensive drugs (systolic blood pressure \> 140 mmHg, diastolic blood pressure b\> 90 mmHg, the specific conditions shall be evaluated by the researchers) have myocardial ischemia or infarction of grade I or above, arrhythmia of grade I or above (including QT interval ≥ 440ms) or cardiac insufficiency; 4. A wound or fracture in the chest or other area that has not healed for a long time; 5. Has a history of substance abuse and is unable to quit or has a history of mental disorders; 6. Patients with past or present objective evidence of pulmonary fibrosis, interstitial pneumonia, pneumoconiosis, radioactive pneumonia, drug-related pneumonia, severe pulmonary function impairment, etc.; 7. Fungus, bacteria, virus or other infection that cannot be controlled or requires antibiotic treatment. The presence of a simple urinary tract infection and uncomplicated bacterial pharyngitis is permitted after consultation with a medical supervisor; 8. For subjects who have used chemotherapy before, according to NCI-CTCAE 4.0, there is grade ≥2 hematological toxicity or grade ≥3 non-hematological toxicity at the time of enrollment; 9. A known history of HIV, or a positive nucleic acid test for hepatitis B (HBsAg positive) or hepatitis C virus (anti-HCV positive); 10. The presence of any indwered catheter or drainage tube (e.g., bile drainage tube or pleural/peritoneal/pericardial catheter). The use of specialized central venous catheters was permitted (the influence of fistula, percutaneous nephrostomy, and indwsed Foley catheters in colorectal cancer patients was considered by the investigators); 11. Brain metastases; A history or medical condition of CNS, such as seizure disorder, cerebral ischemia/hemorrhage, dementia, cerebellar disease, or any autoimmune disease involving CNS; 13\. Significant immunodeficiency; 14. The major therapeutic drugs in this study (including fludalabine, cyclophosphamide, sodium meth, and tozumab and anti-infective drugs used to prevent and treat CRS) have a history of severe hypersensitivity reaction; 15. History of deep vein thrombosis or pulmonary embolism 6 months before enrollment; 16. A history of an autoimmune disease (e.g., Crohn's disease, rheumatoid arthritis, systemic lupus erythematosus) that has resulted in injury to the terminal organs or that requires systemic immunosuppressive/disease-modulating drugs in the past 2 years; 17. Any disease that may interfere with the evaluation of the safety or efficacy of the study treatment.