September 1, 2013
Dr. Lifang Hou is an Associate Professor of Preventive Medicine and Chief of the Division of Cancer Epidemiology and Prevention at Northwestern. Mark Huffman sat down with Dr. Hou to learn more about her career and her work in China.
Mark: Thanks for meeting with me, Lifang. Can you start by telling me about some of the projects that you are working on right now?
Lifang: Some of my primary global health projects are with my Chinese collaborators in Fudan University in Shanghai and in Peking University in Beijing. There are several reasons why I am working in China. First, it is my native country and language; second, I understand the health problems there; and third, I trained as a physician in China. Collectively, these reasons have provided me a number of advantages because I understand the health issues in both China and the US. Further, since I study environmental exposures and their relationships with diseases such as cancer and cardiovascular diseases mediated through epigenetic changes. Given the large degree of environmental exposures in China, there is an opportunity for both Chinese and US investigators to look at these relationships and ultimately improve the health of both countries.
We have recently submitted an R01 this summer to evaluate the relationship between air pollution and progression of chronic obstructive pulmonary disease (COPD).
Mark: To evaluate if people develop faster progression of their COPD with greater exposure to air pollution?
Lifang: Yes, we have been interested in evaluating the progression of different diseases through the lens of epigenetics, particularly tissue-specific epigenetic changes. However, it is very difficult—and often impossible—to obtain heart muscle or vascular tissue from research participants. So we have shifted to evaluating research participants with lung diseases to see if we could collect local tissue in that manner but were again unsuccessful with sputum induction samples. We have decided to pursue evaluation of neutrophils, since COPD is an inflammatory condition reliant upon these cells, which is a unique method that will hopefully provide novel insights into disease progression.
Mark: Who are you working with in China?
Lifang: In Beijng, I work with Prof. Xinbiao Guo who is the chair of Occupational and Environmental Health Sciences at the Peking University School of Public Health.
Mark: How did you get connected with Prof. Guo in the first place?
Lifang: At the International Society of Environmental Epidemiology (ISEE) conference in 2010, he and his colleagues stopped by my poster and asked me about my work. We exchanged our research interests, began talking through biweekly or monthly conference calls, and our collaboration grew from there. Last year, we went to ISEE again, we each brought more members of our teams to meet and developed a schedule on how we are going to pursue joint research proposals together.
Mark: When you think about epigenetics research capacity in China, is that something that you foresee that being a growth area within China itself?
Lifang: Yes, I think Chinese researchers are becoming more globalized because they realize they can learn from US scientists, as we can learn from them. They are really reaching out, and they know that their population is the unique, given the high environmental exposures that affect a large proportion of the Chinese population. The study of epigenetics or use of biomarkers requires differences between or across populations to evaluate changes in things like methylation, and greater differences allows for these differences to be demonstrated more readily (more quickly, less costly) to better understand mechanisms of common, chronic diseases.
Mark: So, you talk about US funding but I presume there might be Chinese funders who be equally interested in this type of work if not, more so?
Lifang: Yes, and I think another approach is that the Chinese funders are also encouraging collaborators from other countries to apply for grants in their home countries to share costs. For example, they want Chinese researchers to apply for grants from Chinese funders, and US researchers to apply for grants from US funders.
Mark: Can you talk a little about one of the visiting scholars who will be coming to Northwestern later this year?
Lifang: Yes, later this year, the Department of Preventive Medicine will host Dr. Jianwei Zhang, who is an associate professor of surgery from Fudan University with an interest in cancer research. The Chinese education ministry has a funding mechanism to send young Chinese scientists to come to US for one year.
Mark: What type of cancer research does he want to do here at Northwestern?
Lifang: He is interested in evaluating the differences between US and Chinese cancer rates. The incidence and case fatality rates of many cancers, such as gastric and esophageal cancers, are different between the two countries, which is why he received funding. There have been joint funding announcements by the US National Cancer Institute and the Chinese equivalent to the National Science Foundation. We have been working with Dr. Vadim Backman from the McCormick School of Engineering on developing new optical biomarkers for earlier cancer detection. He has developed these biomarkers in relatively small in vitro and in vivo samples but needed larger populations for validation. We decided to try and validated these methods in a completely different sample from China to demonstrate the robustness of this method.
Mark: What is an optical biomarker?
Lifang: Vadim has a terrific background developing these methods. He has invented instruments to look at cellular structures on a nanoscale. The concept is based on the field carcinogenesis theory, meaning that if you have cancer in your colon, it is not as though the rest of your digestive system is unaffected from the disease process. If you want to know if this person really needs to have a complete colonoscopy, can you use nanoscale pre-screening of more accessible (rectal, e.g.) tissue to see if the patient has cellular changes that would identify higher-risk individuals? I was immediately struck by this concept, but the theory also has its detractors. After a few visits to China, we submitted our grant with our collaborators from Fudan University.
Mark: The concept of serendipity comes up again and again in some of these conversations and how you go in these different paths that you never planned.
Lifang: I agree—it is exciting. Like I told Don (Lloyd-Jones), it’s always exciting every day. I enjoy working, and we always see things moving forward. You don’t want stop, because everyone on the team is making each other excited to keep moving forward. I think that’s the part that I really enjoy.
Mark: So if I was an enterprising young post-doc here at Northwestern, how would I get to work with you? How would I work in this field?
Lifang: My suggestion is always to anyone who comes to me is to have them work on a small project because I want to see how their work ethic is before we begin anything larger. I always give them guidance and motivation to help them realize their potential, but I think a large degree of their success is because they are self-motivated. I want someone to come to me purely for science and say, “Yes, we are excited, let’s do it!”.
Mark: With gusto!
Lifang: Yes! Another thing that I feel is my collaborations eventually become like one virtual team. We coach each others’ trainees, work collectively, and if the team moves forward, then each member is moving forward.
Mark: Can you talk about any projects that are on the horizon for you?
Lifang: I am moving into a study of epigenetics related to maternal exposures, which can be captured on umbilical cord blood samples. There have been two recent Nature papers that demonstrate the relationship between air pollution and birth weights, and we are interested to see what epigenetic changes might mediate those changes. I also interested in the epigenetic changes associated with weight changes during pregnancy in collaboration with Dr. Linda Van Horn as part of her Maternal Offspring Metabolics Family Intervention Trial (MOMFIT).
Mark: Is there anything that you think the wider Northwestern community should know about your work?
Lifang: I think people should know about the exciting environmental work that is being led by Dr. Teresa Woodruff who has developed an exciting Superfund proposal along with collaborators such as Dr. Bill Funk, who is a new faculty member in Preventive medicine. I think there are increasing resources to improve our cancer epidemiology capacity, including evaluating the relationship with other diseases, such as HIV/AIDS, which is something that Dr. Chad Achenbach is particularly interested in.