Study on the mechanism of Chaihu DaYuan Yin in improving the tumor microenvironment of colorectal mucinous adenocarcinoma

Sun Xun ,Dai Bing ,Quan-Jun Yu ,Zhong-Bao Niu

1Laizhou Hospital of Traditional Chinese Medicine,Laizhou 261400,China.2Affiliated Hospital of Shandong University of Traditional Chinese Medicine,Jinan 250014,China.3Provincial Hospital affiliated to Shandong first Medical University,Jinan 250021,China

Colorectal mucinous adenocarcinoma has the characteristics of high malignant degree,high mortality and low survival rate,easy to recurrence and metastasis after operation,and the prognosis of survival patients is also very poor.The research on immune-related therapy and tumor microenvironment has become a research hotspot.From the point of view of traditional Chinese medicine,Chaihu Dayuan Yin can dispel dampness,resolve phlegm and regulate Sanjiao membrane.It is suitable for tumors with phlegm-dampness and qi stagnation,especially those with abdominal and pelvic dampness heavier than heat,such as colorectal mucinous adenocarcinoma and so on.The concept of resolving phlegm and dredging Sanjiao based on the addition and subtraction of Chaihu Dayuan Yin is of great value to the clinical treatment and basic scientific research of tumors.

Key words:Colorectal mucinous adenocarcinoma，Tumor microenvironment,Immunotherapy,Chaihu Dayuan Yin

Colorectal cancer is a common malignant tumor in clinic,in which mucinous adenocarcinoma is a special pathological type (Figure 1).patients with mucinous adenocarcinoma are not sensitive to chemotherapy and radiotherapy,and they are prone to recurrence and metastasis even after operation,and the prognosis is not ideal.The clinicopathological characteristics of colorectal mucinous adenocarcinoma are characterized by mucus secretion [1].Studies have shown that about 5% to 15% of colorectal cancer patients are pathologically mucinous adenocarcinoma.its main characteristics are high malignant degree,high mortality and low survival rate,and the prognosis of survival patients is very poor.Histologically,the performance of colorectal mucinous adenocarcinoma is special,mainly in the epithelial tissue cancer cells there is a large amount of mucus,so colorectal mucinous adenocarcinoma is characterized by abnormally high mucus secretion [2].The study found that the biological characteristics of colorectal mucinous adenocarcinoma are relatively special,in-depth study of its biological characteristics and According to statistics,the growth rate of colorectal mucinous adenocarcinoma is relatively fast,or the growth cycle is longer,or the degree of infiltration is deeper,the risk of tumor infiltration and growth and spread to the surrounding tissue is relatively high,and the risk of lymphatic metastasis is high,so the stage of the tumor is relatively late.this has a serious impact on the choice of treatment and prognosis of patients.Then,how to improve the prognosis of colorectal mucinous adenocarcinoma through active and effective intervention has become a key problem that we need to solve at present.

Figure 1 Pathological picture of mucinous adenocarcinoma

Why mucinous adenocarcinoma is not sensitive to radiotherapy and chemotherapy? Prone to recurrence and metastasis? Poor forecast? Through clinical observation,we can analyze it from the perspectives of traditional Chinese and western medicine,as follows:From the point of view of western medicine,this is related to the immune environment around the tumor.In recent years,the rapid development of tumor immunotherapy (CIT) highlights the importance of the role of tumor and human immune system.Although CIT has been widely used in human tumors,only a small number of advanced patients get a lasting immune response and survival through CIT.At present,the development of PD-1/PD-L1 inhibitors has led to efficient endogenous anti-tumor immune responses in many patients,resulting in the elimination of cancer cells.This endogenous immune response depends largely on CD8+T cells that specifically recognize cancer cells.By inhibiting PD-1/PD-L1,these immune cells can be reactivated or expanded to identify and kill cancer cells.However,not all tumors have endogenous T cells.

Therefore,the concept of synthetic immunity arises at the historic moment.Synthetic immunity is a treatment that artificially binds cancer cells to T cells,which is usually based on the homologous binding of specific peptide-MHC complexes to T cell receptors[3].It is beneficial to promote the proliferation of non-specific T cells into the tumor.For tumors with poor immunogenicity,it can produce initial anti-tumor immune response,promote the up-regulation of cytokines,induce the death of immunogenic cancer cells,and further stimulate the endogenous anti-tumor immune response.

The combination of endogenous immunity and synthetic immunity has a synergistic effect.In cases where single-drug endogenous immunity or synthetic immunity can be cured,a combination may not be needed.However,many tumors do not show strong enough endogenous immune response to eradicate tumors,nor do they have enough sensitive synthetic immunity to achieve therapeutic effect.Therefore,the organic combination of endogenous immunity and synthetic immunity needs further research.

Figure 2 Tumor characteristic map

Dozens of other types of immune cells can be detected in tumor microenvironment,and the mechanism of many cells in tumor microenvironment is not clear (Figure 2).In addition to the above synthetic immunity and endogenous immunotherapy can inhibit the immune escape of colorectal mucinous adenocarcinoma,there are other cells and immunosuppressive factors involved,even though these components are not the focus of immune research,however,it is undeniable that they play a role in immune regulation and promoting tumor growth.For example,tumor-associated neutrophil (TANs),has the function of supporting tumor progression by producing vascular growth factors such as matrix metalloproteinase-9 (MMP9) and vascular endothelial growth factor (VEGF) in primary and metastatic sites[4].Cancer-associated fibroblasts(CAFs),can promote cancer cell proliferation by secreting some factors,and promote tumor metastasis by secreting C-type lectin domain 3 member B (CLEC3B) [5].Exocrine bodies derived from immune cells play a close role in the communication between immune cells.exocrine bodies from macrophages can also regulate tumor microenvironment and promote tumor progression and spread[6].The presence of Fusobacterium in intestinal flora of colorectal cancer is related to microsatellite unstable(MSI),low level of T cell infiltration and poor clinical outcome [7].In addition,transforming growth factor-β (TGF-β),interleukin-10 (IL-10),chemokine(CCK),prostaglandin E2 (PGE2),cyclooxygenase-2(COX-2) and indoleamine-2-dioxygenase (IDO) can also inhibit the anti-tumor function of immune cells,resulting in low or loss of anti-tumor immune response[8].IL-10 affects cell proliferation,the production of cytokines and the migration ability of effector T cells.IL-10 has multiple anti-tumor effects in tumor inflammatory environment [9].The increase of serum IL-10 level in patients with advanced malignant tumor can be used as a prognostic indicator of disease severity [10].CCL4 can induce the infiltration of tumor-associated macrophages and promote the formation of tumor microenvironment in colon cancer[11].So many factors play an important role in the development of colorectal mucinous adenocarcinoma,which need to be explored and studied in depth.

From the point of view of traditional Chinese medicine,it can be attributed to the disease caused by phlegm and blood stasis.Phlegm is the pathological product of abnormal metabolism of body fluid in the body,which is good at walking and running,so it is easy to metastasize.The ancients had the view that"all diseases are due to phlegm,and most of the strange diseases are caused by phlegm".The metastasis of tumor is closely related to the tumor microenvironment,and the action mechanism of many components in the tumor microenvironment is consistent with the characteristics of phlegm drink in traditional Chinese medicine,which is the direct manifestation of phlegm syndrome at the micro level.Therefore,the principle of resolving phlegm is used to treat tumors in clinic.often receive unexpected curative effect.Dispelling phlegm and removing blood stasis is one of the basic laws for the treatment of tumor.after a large number of clinical pharmacological experiments,expectorant traditional Chinese medicine can act on tumor microenvironment with multiple targets,including cell adhesion and angiogenesis[12].

Tumor recurrence and metastasis,which is closely related to tumor microenvironment,is a hot research field.Tumor microenvironment is an important place for the occurrence and metastasis of tumor cells,which is formed by long-term action.Traditional Chinese medicine believes that:under the influence of long-term adverse factors,it leads to the mutual obstruction of phlegm in the human body,which is the rootcauseoftheformationoftumor microenvironment.Therefore,we also call the tumor microenvironment "phlegm environment" [13].JingYue complete Book says:"phlegm salivation is based on qi and blood,if its positive,then viscera disease,fluid failure,and qi and blood is sputum salivation." sputum saliva is originally qi and blood body fluid,but because of its abnormal metabolism,disease is formed,just like the formation of tumor microenvironment.Studies have shown that the occurrence of a variety of tumors are inextricably linked with chronic inflammation.Under the long-term stimulation of chronic inflammation,normal cells and tissues can easily lead to gene mutation and canceration [14],such as gastric cancer,colon cancer,pancreatic cancer and so on.

Traditional Chinese medicine has always attached importance to the balance of yin and yang,and in the process of tumor treatment,it shows the balance between the human body and the tumor.In the process of transforming the tumor and the microenvironment,the balance between the human body and the tumor is restored.In this environment,tumor cells stop proliferating or proliferate slowly,and survive with tumors,so that the survival time of patients can be prolonged and the quality of life can be improved.At present,a large number of studies have confirmed that traditional Chinese medicine plays an effective role in inducing tumor differentiation.The differentiation of tumor cells induced by traditional Chinese medicine can regulate the imbalance between proliferation and differentiation at the cellular and genetic level,so that tumor cells develop into mature cells and lose their malignant characteristics[15].The standard of curative effect is the loss of malignant phenotype of tumor and the prolongation of survival time.Not or not just a change in the size of the lump.This opens up a new train of thought for the anti-tumor therapy of traditional Chinese medicine [16].Therefore,for the treatment of tumor,using the method of transforming tumor cells and microenvironment to correct its evil,rather than blindly killing and attacking,just like the dredging method adopted by Dayu in flood control,it can be regarded as a new way of tumor treatment.

After a large number of clinical practice,the addition and subtraction of the prescription based on Chaihu Dayuan Yin has a significant effect on colorectal mucinous adenocarcinoma.Chaihu Dayuan Yin comes from"popular Treatise on febrile Diseases",its function:reconciling Sanjiao,main phlegm and malaria.For the concept of the original membrane,the earliest can be seen in the"plain question":"the cold is between the membrane of the small intestine,collaterals and blood,blood crying can not be injected into the menstruation,blood gas can not be retained,so it has accumulated in the past." Wu can also put forward the conclusion of the pathological changes of the membrane according to the location and quality of the membrane,saying:"if the disease is caused by evil entering from the mouth and nose,then the guest,not in the Tibetan mansion,not in the meridians,in the Fu ridge,not far away from the stomach,is the boundary between the exterior and the interior,which is half the surface and half the interior,that is,the needle meridian is the so-called transverse membrane."Taking a comprehensive view of the above discussion,for the interpretation of the membrane,most doctors of later generations think that the membrane is between half the surface and half the interior.From the holistic view of traditional Chinese medicine,Moyuan,Shaoyang and Sanjiao belong to the half-surface and half-interior level,and their physiological functions can be summarized as follows:water-Sanjiao to desecrate the waterway;fire-gallbladder to occupy less fire;Qi-Sanjiao to use the original qi as a different way.Membrane is the door for the gasification and closing of Sanjiao.The film is the body of Sanjiao,and Shaoyang is the use of Sanjiao.Therefore,the membrane is a membranous tissue widely distributed in the body,muscle,viscera and body,which is similar to the membrane system of western medicine.there are neurovascular lymphatic vessels in these membranous structures.it is what we call the passage of qi,blood and body fluid.

Chaihu Dayuan Yin,In the prescription,Bupleurum and Scutellaria baicalensis were used as monarch drugs,Radix Aurantii Shuda and Radix Scutellariae were used to release the original qi,while Radix Aurantii and Platycodon grandiflorum dredged Shangjiao,Magnolia officinalis,grass and fruit,green peel and betel nut were used as courtier medicine.Add lotus stem through it;mix it with licorice.Then add and subtract according to the characteristics of phlegm-dampness,blood stasis deficiency and cancer toxin in patients with colorectal mucinous adenocarcinoma,such as Fructus gansui,white mustard seed,gecko,yew,subphrenic Zhuyu decoction,Shaofu Zhuyu decoction and so on.It is better to adjust the key points of Sanjiao,such as passing through the internal and external organs,inside and outside the left and right qi,Taichong,Qihai and so on.

To sum up,"phlegm"is not only a kind of physique,but also a local microenvironment.It is precisely because of the existence of this microenvironment that our bodies are prone to "accumulation".The microenvironment of tumor can be regarded as a microscopic extension of the characteristics of turbid phlegm.The concept of resolving phlegm and dredging Sanjiao,which is based on the treatment of Chaihu Da Yuan Yin,has been proved to be effective in improving the tumor microenvironment of colorectal mucinous adenocarcinoma and preventing tumor recurrence and metastasis.and it has great scientific research value for the clinical basic research of tumor.