We first went to XuanWu Hospital in Beijing and interviewed Dr. Hongyan Li, who is currently the director of the Gastrointestinal Tumor Comprehensive Treatment Ward of the General Surgery Department and is engaged in clinical and scientific research on oncological diseases and chronic diseases and immune-inflammatory diseases.

In the interview, Dr. Li emphasized the remarkable potential of naturally sourced anticancer drugs, especially in improving the sustainability of cancer treatments. She believes that optimizing the production process of these drugs will not only help improve efficacy, but also reduce dependence on natural resources. Increasing the yield and purity of these natural drugs through synthetic biology approaches may provide new options for cancer treatment. In particular, if the mechanism of action of these drugs can be revealed through precise molecular mechanism studies, it will help to develop more targeted therapeutic regimens with fewer side effects and improved efficacy.

Q1: As an expert in the field of colon cancer, can you tell us about the current status of colon cancer incidence and survival in the world, especially in East Asia?

A1: Colon cancer is one of the tumors of the gastrointestinal tract, and its incidence has been increasing globally in recent years, especially in Southeast Asia. The age of onset of colon cancer is usually over 40 years old, with a higher percentage of patients over 50 years old. Currently, treatment strategies for colon cancer mainly include surgery and drug therapy. With the development of medical technology, treatment has gradually shifted from traditional chemotherapy to targeted therapy and immunotherapy, marking a new era of more precise and individualized tumor treatment. In different stages of the disease, patients usually need to use a combination of multiple treatment modalities to achieve better therapeutic effects.

Q2: What are the limitations of traditional chemotherapy in colon cancer treatment?

A2: Traditional chemotherapy faces many limitations in the treatment process. Many patients associate serious side effects such as hair loss, nausea and vomiting with the mention of chemotherapy, and some patients even have reflexive discomfort when they hear the word chemotherapy. These side effects not only affect the patient's quality of life, but may also lead to interruption of the treatment cycle or adjustment of drug dosage, thus reducing the effectiveness of treatment. Modern medicine is moving towards precision and individualized treatment, and through technologies such as gene sequencing, it is possible to provide more precise treatment for each patient's specific condition. In addition, as science and technology continue to advance, new anti-cancer drugs continue to emerge, and more innovative solutions are available for tumor treatment.

Q3: Are anticancer drugs of natural origin widely used in today's clinical applications?

A3: In tumor therapy, drug therapy, especially in the treatment of digestive tract tumors, still occupies a very important position. Although traditional chemotherapeutic drugs are still widely used, precision targeted therapy and immunotherapy are gradually becoming new directions. The research on drugs of natural origin is also getting deeper and deeper. Studies have shown that a number of substances of natural origin have shown anticancer effects in in vivo and in vitro experiments. The potential of such drugs is gradually being recognized, but in-depth mechanistic studies are still needed to determine their specific anti-cancer pathways. For example, understanding whether they work by regulating biological processes such as tumor cell growth, apoptosis, and angiogenesis will be a focus of future research.

Q4: How do you see the future of natural source products in anti-cancer therapy?

A4: Anti-cancer drugs of natural origin have received more and more attention in recent years. Experimental studies have shown that these substances have the potential to inhibit tumor growth in vivo in mice and in cellular models. However, their specific pharmacological effects and molecular mechanisms, especially targeting through signaling pathways, still need further in-depth study. In addition, how to apply the research results in basic medicine to clinical practice to ensure that these natural substances have the same effect in human body is also an urgent problem to be solved in the future. Overall, drugs of natural origin provide a new direction for tumor therapy and deserve to be explored in depth in future studies.

Dr. Yuxin Zhong

We then went into the Cancer Hospital of the Chinese Academy of Medical Sciences (CAMS) and got in touch with three attending physicians from CAMS.

Dr. Yuxin Zhong is a visiting scholar at Harvard Medical School and has developed a set of treatment methods with his own characteristics in the surgical treatment of gastrointestinal, retroperitoneal and hepatobiliary-pancreatic tumors.

In this interview, facing the use of natural source drugs in gastric cancer treatment, Dr. Zhong expressed high concern about natural source anti-cancer drugs. He believes that the research of natural compounds has potential breakthrough significance in gastric cancer treatment, especially when these compounds are used in combination with existing chemotherapeutic drugs, which may have the effect of effectively enhancing the efficacy and reducing the side effects.

Q1: As an expert in the field of gastrointestinal tumor management, can you introduce the current epidemiology of gastrointestinal tumors or gastric cancer?

A1: Gastrointestinal tumors mainly include colorectal cancer, stomach cancer, liver cancer, esophageal cancer, pancreatic cancer and gallbladder cancer. Among them, liver cancer has the highest mortality rate, followed by stomach, colorectal, esophageal, pancreatic and gallbladder cancers. Globally, gastrointestinal tumors account for more than 25% of all tumor incidence and 35% of tumor-related mortality. The prognosis of colorectal cancer has improved greatly through early screening, but most other types of gastrointestinal tumors are at a more advanced stage at diagnosis and have a poor prognosis.

Q2: In your opinion, what are the main factors that induce gastric cancer?

A2: The predisposing factors of gastric cancer are diverse, for example, Helicobacter pylori (HP) infection is considered to be one of the most dominant factors of gastric cancer in East Asia. In addition, Chinese branch testicular schistosomiasis, which is widely prevalent in East Asia, especially in Guangdong, Guangxi and Heilongjiang regions of China, can be considered to be included in the list of geographically unique predisposing factors that trigger gastrointestinal tumors.

Q3: What are the current relevant means of gastric cancer treatment?

A3: Surgery is a common treatment modality for gastric cancer treatment at present. Surgery includes partial gastrectomy, total gastrectomy and lymph node dissection, aiming at removing the tumor and its surrounding tissues in order to cure or prolong the patient's survival. For example, patients with early-stage pyloric adenocarcinoma usually undergo partial resection, while advanced gastric cancer may require more extensive gastrectomy and lymph node dissection. Chemotherapy is another conventional means of gastric cancer treatment, which kills cancer cells or inhibits their proliferation through the use of chemicals. Drugs such as fluorouracil, oxaliplatin and cisplatin are commonly used in chemotherapy regimens, and common regimens include FOLFOX (fluorouracil + oxaliplatin + folinic acid) and XELOX (fluorouracil + cisplatin). The above are the more traditional treatments for gastric cancer, and the more cutting-edge treatments at present are like targeted therapy, which is a kind of therapeutic method to intervene in the specific biological targets of tumor cells. Commonly used targeted drugs include trastuzumab and ranibizumab, which can achieve therapeutic effect by inhibiting the growth signaling pathway of cancer cells or inhibiting angiogenesis and other mechanisms. For example, HER2-positive gastric cancer patients can be treated with trastuzumab. In addition, immunotherapy is also a treatment that we will consider, for example, using immunotherapy drugs including PD-1 inhibitors and PD-L1 inhibitors, and some patients with advanced gastric cancer may be treated with PD-1 inhibitor drugs such as pabolizumabb.

Q4: Is there any precedent in the field of gastric cancer treatment for consuming small molecules of natural origin in combination with chemotherapeutic agents?

A4: Natural compounds like curcumin have been studied for use in combination with chemotherapeutic agents. As a drug curcumin has anti-inflammatory, antioxidant and anti-tumor activities and has now been found to enhance the anti-cancer effects of certain chemotherapeutic drugs while reducing their toxic side effects. However, research on the combination of small molecules of natural origin with chemotherapeutic agents is still in the early stages and may provide new ideas and options for gastric cancer treatment. However, these potential therapies require further clinical studies to confirm their safety and efficacy to ensure their application in clinical practice.

Q5: Some of your outlook on products of natural origin in the direction of anticancer?

A5:Take the example of Sulforane that you are currently working on, as a natural compound, it has been found to have promising properties in the field of cancer therapy, especially in apoptosis, inhibition of neoangiogenesis, and blockage of tumor metastasis, which would make clinicians consider incorporating it into their prescriptions, but before it can be put into clinical use, the possible genetic residues and some ethical issues associated with the use of synthetic biology for Sulforaphane would need to be addressed. However, before clinical use, the genetic residues and ethical issues that may be associated with the use of synthetic biology to obtain Sulforaphane need to be resolved, and it will be a long road from the laboratory to the clinic, but nonetheless, we physicians will remain positive about new drugs that can benefit patients.

Dr. Zhijie Wang

Dr. Wang is a doctor who is particularly good at molecular typing of lung cancer, peripheral blood genetic testing, and comprehensive treatment based on chemotherapy, molecular targeted therapy and immunotherapy for lung cancer. When it comes to expectations for synthetic biology approaches to treatment, Dr. Wang points out that optimizing the production of these drugs through synthetic biology can increase the yield of the drugs while maintaining their activity and purity, thus providing perhaps more effective treatment options for cancer patient patients. At the same time, naturally sourced drugs may help mitigate the toxic side effects of conventional chemotherapy drugs and improve patients' quality of life.

Q1: Can you give an overview of the epidemiology of lung cancer?

A1: Lung cancer is one of the most common cancers in the world and is mainly categorized into small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC), with NSCLC accounting for 85% of all lung cancer cases. Adenocarcinoma is the most common subtype of NSCLC, with a high incidence especially in developed countries and among never smokers. The incidence of lung adenocarcinoma is increasing yearly in low- and middle-income countries, especially in East Asia. The global five-year survival rate for lung cancer averages between 15% and 20%, and early diagnosis and treatment are essential to improve survival. Survival time for patients with advanced lung cancer is usually less than one year. Treatment varies depending on the stage of the cancer, with surgery or radiotherapy used in the early stages, and reliance on chemotherapy and targeted therapies in the middle and late stages.

Q2: What is the role of chemotherapeutic agents of natural origin in lung cancer treatment?

A2: Natural products play an important role in the treatment of lung cancer and other solid tumors. For example, paclitaxel, a chemotherapeutic drug extracted from the red bean tree, has been widely used in the treatment of lung cancer. Compared with traditional chemotherapeutic drugs, the natural product has less residue and lower side effects, which helps to improve the quality of life of patients.

Q3: What are the major limitations of current chemotherapeutic agents?

A3: The major challenges of current chemotherapeutic agents include increased drug resistance, severe side effects and high treatment costs. For example, pemetrexed, a drug that inhibits the metabolism of folic acid, may lead to side effects such as decreased blood counts and anemia, as well as reactions such as skin darkening in some patients, all of which affect the patient's treatment experience and adherence.

Q4: Are there any successful precedents of combining small molecules of natural origin with chemotherapeutic agents?

A4: Yes, paclitaxel is a successful example. Paclitaxel kills cancer cells by stabilizing microtubules and inhibiting cell division. Combining paclitaxel with cisplatin or carboplatin analogues can increase the sensitivity of cancer cells to treatment, increasing the survival rate and outcome of patients with non-small cell lung cancer.

Q5: What is your opinion on the use of Sulforaphane in combination with conventional chemotherapy drugs?

A5: Sulforaphane is an isothiocyanate from the cruciferous plant family with potential anticancer effects. Combining Sulforaphane with conventional chemotherapy drugs is expected to improve the therapeutic efficacy and reduce the toxic side effects. As a clinician, I have a positive attitude toward any treatment option that has the potential to improve efficacy with fewer side effects than conventional chemotherapy.

Dr. Zhen Wang

Finally, the team members interviewed Dr. Zhen Wang through an online interview. Dr. Wang specializes in the diagnosis and treatment of thoracic tumors such as esophageal cancer, esophagogastric conjunction cancer, mediastinal tumors, chest wall tumors, and other thoracic tumors.

Dr. Wang expressed his strong interest in the application of anticancer drugs of natural origin,, in the treatment of esophageal cancer. He believes that the large-scale production of such promising anti-cancer molecules through synthetic biology may lead to safer and more effective treatment options for esophageal cancer patients. Particularly in the combination of chemotherapeutic agents, natural origin drugs may help to enhance the therapeutic effect and alleviate the side effects, thus improving the survival rate and quality of life of patients

Q1: For patients with esophageal cancer, how are the current treatments chosen according to their condition?

A1: The treatment of esophageal cancer depends on the specific condition of the patient. For example, for patients with early-stage tumor lesions (e.g. T1N0M0, T2N0M0) without lymph node metastasis, radical surgery is usually used without drug treatment. In contrast, for patients with locally advanced disease with lymph node metastasis or large tumors (e.g., T3N0M0, T4N0M0), a combination of treatments that includes radiotherapy, surgery, and postoperative complementary therapy will be used. For patients with advanced lesions, especially those who have developed lymph node metastasis, a comprehensive treatment mode mainly based on chemotherapy will be adopted.

Q2: What are the commonly used drugs in the treatment of esophageal cancer? What are their effects?

A2: Director Wang pointed out that there are relatively few effective chemotherapy drugs in esophageal cancer treatment. Pyrimidines, paclitaxel and platinum drugs are usually used in first-line treatment, among which paclitaxel performs better. In recent years, paclitaxel has been improved, evolving from regular paclitaxel to polyene paclitaxel to albumin-bound paclitaxel, and these improvements have greatly reduced the toxicity of chemotherapy, lowered the risk of side effects such as diabetes mellitus, and enhanced the efficacy of chemotherapy. Second-line treatment, on the other hand, usually uses second-line chemotherapeutic agents such as gemcitabine, but their therapeutic effectiveness is low. Therefore, more and more treatment options use chemotherapy combined with immunotherapy.

Q3: Are there any limitations to the use of chemotherapy drugs?

A3: The limited use of chemotherapeutic agents is mainly due to the inability to predict the effectiveness of chemotherapeutic agents through genetic testing, resulting in the inability to accurately determine the effective population. In addition, chemotherapeutic agents are often associated with significant adverse effects, such as bruising, and immunotherapy is often associated with immunosuppression. Many patients, especially in East Asia, are too thin and malnourished to withstand the high intensity of high-dose chemotherapy.

Q4: How effective is sulforaphane (SFN) in combination with conventional anticancer drugs?

A4: Through the accumulation of data and screening of small molecule anticancer drugs, we are confident that we can find small molecule drugs that can be applied to the treatment of esophageal cancer. As a potential natural small molecule, sulforaphane (SFN) is expected to synergize with other anticancer drugs to improve the therapeutic effect.

During his presentation, team members learned that Sulforaphane, a natural anticancer molecule, is highly regarded for its pleiotropic properties and low side effects. However, due to its extremely low levels in the daily diet, there is a need to find a more efficient way to absorb and utilize this substance. The unique properties of Sulforaphane have placed them at the forefront of orthomolecular nutrition and have been the focus of many studies.

In his research, Eng. Javier Pimentel highlighted the pleiotropic properties of Sulforaphane, which means that not only do they exert anti-inflammatory, antioxidant, and anticancer effects, but they also have the properties of a natural antibiotic. Dr. Pimentel explains that Sulforaphane triggers multiple positive physiological responses with a single action, like "shooting multiple birds with one stone". In addition, the combination of Sulforaphane with other nutrients such as Magnesium, Vitamin C, Vitamin D3 and Omega-3 can further enhance its effectiveness and provide comprehensive health protection.

Prof. Yuan is an expert in synthetic biology and his main research areas are synthetic biology and metabolic engineering, scale-up of high purity natural products and activity research.

Prof. Yuan's research emphasizes the therapeutic potential of Sulforaphane as a broad-spectrum anticancer natural compound. In animal models and cellular experiments, Sulforaphane showed inhibitory effects against a wide range of cancers and significantly prolonged survival and improved quality of life in patients with advanced cancer. Compared with conventional chemotherapeutic agents, Sulforaphane sulfanilamide has fewer toxic side effects and is relatively safe even at high doses. Its anti-cancer mechanism is mainly through enhancing the body's immune response and inhibiting the immune escape of cancer cells to effectively kill cancer cells. Relevant studies have laid the foundation for the drug development of Sulforaphane sulfide, and it has passed the phase II clinical trial of the U.S. FDA, especially in the treatment of prostate cancer, showing good prospects.

The application of Sulforaphane in cancer therapy is highly feasible, and the improvement of its biosynthesis method provides an effective way to increase the yield, reduce the cost, and ensure the quality of the product, which is expected to make this anticancer substance more widely used in clinical applications and benefit more cancer patients.

According to Prof. Qipeng Yuan, as a broad-spectrum anticancer natural compound, Sulforaphane shows remarkable therapeutic potential. First of all, Sulforaphane has inhibitory effects on a wide range of cancers and has demonstrated extensive anticancer activity in both animal models and cellular experiments, especially in advanced cancer patients, which can significantly prolong the survival and improve the quality of life of the patients. In addition, due to its natural plant origin, Sulforaphane \has the advantage of having fewer toxic side effects than traditional chemotherapeutic drugs, which makes it safer to use in cancer treatment, especially when used at high doses, and still has fewer side effects.

In terms of molecular mechanism, Sulforaphane can inhibit the immune escape of cancer cells by enhancing the immune response of human body, and then effectively kill cancer cells. The research on its mechanism has been relatively in-depth, which has laid a solid foundation for the drug development of Sulforaphane. Meanwhile, Sulforaphane has passed the phase II clinical trial of the U.S. FDA for the treatment of prostate cancer and has shown good prospects in the treatment of other cancers, such as pancreatic cancer. Although Sulforaphane sulfide has not yet been applied to clinical treatment on a large scale, existing studies and experimental results show that it is expected to become an important anti-cancer drug.

The production of Sulforaphane by biosynthesis has significant advantages over the traditional plant extraction method. Firstly, biosynthesis greatly increases the yield of Sulforaphane, thus effectively solving the problem of low yield in the current plant extraction method. Prof. Yuan mentioned that through the fermentation method, the yield of a single 50-ton fermenter is equivalent to 18,000 acres of traditional plant cultivation, which means that biosynthesis far surpasses the traditional method in terms of scale and efficiency. In addition, the biosynthesis method can also significantly reduce the production cost. The price of Sulforaphane is expected to drop from the current RMB 200,000 per kilogram to about RMB 5,000 per kilogram, which substantially reduces the financial burden of patients and enables this promising anticancer substance to be more widely used in the clinic.

In summary, the application of Sulforaphane in cancer therapy is highly feasible. The biosynthesis method can not only greatly increase the yield and reduce the cost, but also ensure the stability and purity of the product, which can promote the wide clinical application of Sulforaphane for the benefit of more cancer patients.

After an in-depth discussion with Prof. Xiaolin Shen from the School of Life Science and Technology, Beijing University of Chemical Technology, we decided to optimize the yeast chassis for efficient production of high-purity Sulforaphane using synthetic biology strategies in our current research program.

In synthetic biology, promoters are the key to gene expression. To improve the production of Sulforaphane, we will optimize the relevant promoters in yeast, identify efficient promoter sequences through experimental screening and computer simulation, and create promoter libraries. In addition, metabolic engineering will enhance key nodes in the Sulforaphane synthesis pathway through gene editing. We will also optimize the activity and stability of P450 enzymes and improve their expression in yeast through protein engineering. Through these integrated means, we aim to construct an efficient yeast production platform to enhance the industrial production efficiency of Sulforaphane.

After completing the background investigation and the design of the experiment, the team conducted a preliminary experiment. In order to improve the experiments and achieve better results, the team members interviewed researcher Yongjin Zhou, the leader of the Synthetic Biology and Biocatalysis Innovation Special Zone at the Dalian Institute of Chemical Physics, Chinese Academy of Sciences (DICP). Facing the advantages and challenges of addressing the application of yeast in synthetic biology, Zhou pointed out that by optimizing promoter combinations and strengthening metabolic pathways, the yield and growth rate of yeast can be significantly improved, especially in enhancing the activity of key enzymes. He pointed out that codon optimization is an important means to improve the expression efficiency of p450 enzymes despite the difficulties they face in yeast. In addition, Dr. Zhou believes that biosynthesis is far superior to chemical synthesis and plant extraction in the production of natural products and has great potential for industrial applications.

In the discussion Researcher Zhou highlighted the potential of optimizing promoter combinations and gene library construction to enhance yield and growth rate in yeast. Although these methods have been widely used in E. coli, their application in yeast is still relatively scarce. Meanwhile, researcher Zhou pointed out that the promoter core region of Saccharomyces cerevisiae is not as well defined as that of E. coli, but optimizing gene expression through combinations of promoters and terminators of different strengths is still a feasible and effective approach. In practice, different combinations of promoters may lead to a more than tenfold difference in gene expression activity, providing an important idea for gene expression optimization in yeast systems.

At Tsinghua University, we had the honor to interview Prof. Chun Li, who has been engaged in metabolic engineering and synthetic biology research for a long time. Prof. Li Chun proposed a modular design and dynamic regulation strategy for long metabolic pathways and discussed with us an effective method to optimize industrial fermentation conditions through gene editing technology. Regarding the application of p450 enzyme, he suggested the use of directed evolution and rational design to enhance its catalytic efficiency, as well as biosafety design, such as gene lock, to ensure the safety and environmental friendliness of genetically engineered yeast.

While making improvements to the wet experiment, team members contacted Prof. Xinxiao Sun at Beijing University of Chemical Technology and discussed the challenges and potential solutions to the metabolic simulation process.

Our research focused on optimizing the three-step synthetic pathway of Sulforaphane. Despite initial attempts to find alternative reactions through database searches, this traditional approach had significant shortcomings in pathway design and accuracy. Prof. Sun pointed out that the traditional database approach could not comprehensively cover all possible metabolic pathways and relied too much on existing reaction data, limiting our ability to systematically identify optimal pathways. To solve these problems, we decided to introduce a pathway design algorithm to develop a brand-new pathway for Sulforaphane biosynthesis based on multiple enzyme and reactant databases. We first applied the Network Reducer algorithm to simplify the genome-scale metabolic network model of Saccharomyces cerevisiae in order to reduce model complexity and make it more suitable for computation and analysis. The simplified model represents metabolites and reactants in the form of CxNy, which lays the foundation for further processing. In this process, although the element sulfur is crucial in some reactions, we temporarily ignored its effect in order to initially simplify the model and reduce computational complexity. Subsequently, we transformed the simplified metabolic network model into SBML (Systems Biology Markup Language) format by the SlimGEM algorithm and plan to utilize algorithms such as pFBA (Parsimonious Flow Balance Analysis) to compute feasible paths in the metabolic cycle to identify optimal reaction sequences.

The old traditional path simulation methods are simple to use and easy to understand, but their shortcomings are also obvious; they cannot systematically identify complete paths and rely on a single database, which makes them less feasible in practice. It is these shortcomings that motivate us to explore a more systematic approach to improve pathway design. While the new pathway design algorithms are still being optimized, we have achieved preliminary results, including optimization of side chain extension, synthesis of core glucosides, and improvement of amino acid side chain modifications. These efforts lay the groundwork for the large-scale production of Sulforaphane.

To further improve dry experiments and to address how to optimize enzyme function in yeast landraces. Team members had discussions with Prof. Ulrich Schwaneberg from RWTH Aachen University, Germany. Prof. Schwaneberg provided valuable advice on the low efficiency of the enzyme, the complexity of the multicomponent system, and the inconsistent stability and expression levels of the CYP450 enzyme. He emphasized that the catalytic efficiency and selectivity of the enzyme can be effectively improved by improving the hydrophilicity and structure of the substrate channel and substrate binding pocket through molecular dynamics simulation and rational design. In addition, the use of "co-expression system" to co-express CYP450 enzyme and its reductase in the same vector can help to improve the overall catalytic efficiency and reduce the stability problem during the expression and use.

Prof. Schwaneberg also reminded us to avoid over-optimization of a single enzyme system under time constraints and suggested focusing on optimizing enzymes that have been validated in experiments. These suggestions provide a clear direction for us to further optimize the function of CYP450 enzymes in the yeast chassis, on which we will improve our research design and experimentally verify their practical effects.