PhD Thesis Award 2024

The Graduate School establishes the PhD Thesis Award to recognise, reward and promote the distinguished research achievements by graduating PhD students. There are two award classes, namely Outstanding and Merit, recognising students’ performance of different levels.

PolyU PhD Thesis Award - Outstanding Award
PolyU PhD Thesis Award - Merit Award

Outstanding Award

Targeting the underlying mechanisms of resistance to immunotherapy with the goal of developing a more effective treatment for deadly liver cancer.

Faculty of Science (FS)
Department of Applied Biology and Chemical Technology (ABCT)

Dr LEI Mang Leng

Thesis Title: Identification of Wild-Type Kirsten Rat Sarcoma (Kras) and its Signalling Pathway in Immune Evasion in Hepatocellular Carcinoma

- For contribution to enhance the therapeutic efficacy of current immunotherapy in liver cancer

Chief Supervisor: Professor Terence LEE

Although immunotherapy demonstrate tremendous promise for the treatment of hepatocellular carcinoma (HCC) patients, their response rates are modest (~15%). Increasing evidence indicates that activation of oncogenic pathways contributes to an unfavourable tumour microenvironment, resulting in resistance to immunotherapy. Using an antigen-expressing c-MycOE /Tp53KO HCC mouse model, DIA-MS proteomics identified oncogenic KRAS signalling pathway as a crucial mediator of immune evasion and confers resistance to anti-PD-1 therapy. Wild-type KRAS was highly upregulated in immune-escaped tumours, with concurrent activation of EGFR/MEK/ERK signalling. Endogenous Kras overexpression increased tumour burden and reduced survival in mice. KRAS exerted inhibitory effects on both intrinsic and extrinsic interferon (IFN) responses, leading to the downregulation of MHC-I expression and dampened CD8+ T cell activity. Notably, combination therapy with MRTX0902, trametinib, and anti-PD-1 antibody effectively increased intratumoural CD8+ T cell infiltration and improved survival. This study provided new insights into the therapeutic potential of targeting the wild-type KRAS pathway to increase the efficacy of anti-PD-1 therapy in HCC.

Merit Award

This research provides a revolutionary way to implement sound control technology based on acoustic metamaterials and holds promise for applications in underwater wireless communication.

Faculty of Engineering (FENG)
Department of Mechanical Engineering (ME)

Dr FAN Haiyan

Thesis Title: Non-Hermitian Topological Phases in Elastic and Acoustic Lattices

- For contribution to precise sound control and defend against intrusion by small underwater targets

Chief Supervisor: Professor SU Zhongqing

Natural materials usually have inherent acoustic characteristics that are difficult to meet the special needs in precise sound control. In this thesis, the proposed metamaterials show unprecedented abilities to engineer the characteristics of sound including but not limited to amplitude, phase, frequency and mode shape, thereby improving sound detection resolution and enhancing the signal-to-noise ratio. This thesis starts with one-dimensional (1D) metamaterials with additional loss treatments to produce a gathering effect of the weak acoustic signals, which amplifies the signals by 9 times. Then, we extend to a two-dimensional (2D) space, achieving high directivity anti-interference sound wave beam based on the valley Hall effect, solving the problem that target acoustic signal propagation is susceptible to interference. Last but not least, a three-dimensional (3D) metamaterial with fluid-solid interaction coming into play which improves the identification ability of underwater small target acoustic signals. These works offer potential applications in acoustic detection and identification of underwater small targets.