Hepatocellular carcinoma: Therapeutic advances in signaling, epigenetic and immune targets

Table 1 Known dysregulated pathways and genes in hepatocellular carcinoma with mode of action and frequency (modified from[4,5,92])

Pathways / genes	Alteration	Frequency in HCC
AKT-mTOR-MAPK signaling
RPS6KA3	Mutation	2%%-9%
TSC1 and TSC2	Mutation or deletion	3%-8%
PTEN	Mutation or deletion	1%-3%
FGF3, FGF4 and FGF19	Amplification	4%-6%
PI3KCA	Mutation	0%-2%
Angiogenesis
VEGFA	Amplification	3%-7%
Antioxidation
NFE2L2 KEAP1	Mutation Mutation	3%-6% 2%-8%
Cell cycle control/tumor suppressors
TP53*	Mutation or deletion	12%-45%
RB1	Mutation or deletion	3%-8%
CCND1*	Amplification	5%-14%
Epigenetic and chromatin remodeling
ARID1A*	Mutation or deletion	4%-17%
ARID2*	Mutation	3%-18%
BAP1	Mutation	5%[117]
Immortalization/telomere maintenance
ERT*	Promotor mutation amplification	54%-60% 5%-6%
JAK/STAT
JAK1	Mutation	5%
Metabolic pathways
Afamin apoptogenic protein 1, mitochondrial	Mutation	Up to 10%[117]
Oncogenes
MET*	Amplification	30%-50%
MYC	Amplification	4%
TGFβ pathway
Osteopontin	Mutation	Up to 40%[118]
G2/mitotic-specific cyclin-B2 Cyclin-dependent kinase 1 lymphoid enhancer-binding factor 1
Integrin α2
Wnt pathway
Catenin β1*	Mutation	11%-37%
AXIN1*	Mutation or deletion	5%-15%

HCC: Hepatocellular carcinoma.

Table 2 Summary of classification schemes of hepatocellular carcinoma (modified from[119])

First author	Lee et al[120]	Boyault et al[121]	Chiang et al[122]	Hoshida et al[123]	Désert et al[124]	TCGA network[117]
Year	2004	2006	2008	2009	2017	2017
HCC cases	91	56	91	232	1133	559
Number of subgroups	2	6	5	3	4	3
Names of classes	Cluster A/B	G1-G6	CTNNB1-proliferation	S1-S3	PP, PV, ECM, STEM	iCluster1-iCluster3
Major applied technology for molecular profiling
Transcriptomics	X	X	X	X	X	X
Genetic Mutations		X				X
Copy number alterations			X			X
Metabolomics					X
Epigenomics		X (CDH1 and CDKN2A)				X
Proteomics						X
Major HCC Classes with clinic-pathological features and high mutation rates
Proliferative phenotype
Poor outcome	A	G1, G2, G3	Proliferation	S1 + S2	ECM + STEM	iCluster 1 + 3
High AFP
Moderate to poor differentiation
P53
Non-proliferative phenotype
Good to moderate outcome	B	G5, G6	CTNNB1	S3	PP + PV	iCluster 2
Low AFP
CTNNB1

ECM: Extracellular matrix; PP: Periportal; PV: Perivenous; STEM: Stem/progenitor cells; HCC: Hepatocellular carcinoma.

Table 3 Clinical trials with chimeric antigen receptor T cells cells in hepatocellular carcinoma

NCT	Antigen	Phase	Patients	Sponsor	Status	Comments
NCT02715362	GPC3	I/II	30	Company	Recruiting	HAI
NCT03672305	c-Met/PD-L1	I	50	Academic	Not yet recruiting	IV
NCT02723942	GPC3	I/II	60	Academic	Completed
NCT03198546	GPC3	I	30	Academic	Recruiting
NCT02395250	GPC3	I	13	Academic	Completed	[58]
NCT03349255	AFP	I	18	Company	Recruiting	IV vs HAI
NCT03130712	GPC3	I/II	10	Company	Recruiting	IT
NCT03084380	GPC3	I/II	20	Academic	Not yet recruiting	Combination with TACE
NCT029051881	GPC3	I	14	Academic	Not yet recruiting
NCT03302403	GPC3	I	48	Academic	Not yet recruiting
NCT03146234	GPC3	I	20	Academic	Recruiting
NCT01935843	Her2	I/II	10	Academic	Unknown
NCT02959151	GPC3	I/II	20	Company	Unknown
NCT02587689	MUC1	I/II	20	Company	Unknown
NCT03013712	EpCAM	I/II	60	Academic	Recruiting

¹Location of study is United States, all other trials are conducted in China. HAI: Hepatic artery infusion; IT: Intratumoral injection; IV: Intravenous injection; TACE: Transarterial chemoembolization.

Table 4 Available techniques for induction of hepatocellular carcinoma in relation to temporal and technical aspects as well as major advantages and disadvantages (summarized from[92])

Method and specification	Time to HCCshort (+) to long (+++)	Technical effortslow (+) to high (+++)	Major “Pros” (+) vs “Contras” (-)
Chemotoxic agents linked models
Diethylnitrosamine	++	+	(+) good combination options with other methods
9,10-dimethyl-1,2-benzanthracene			(-) time to HCC not easily predictable
Direct implantation of tumor cells or tissue
Heterotopic/orthotopic	+	+/++	(+) heterotopic xenografts are often and easily done
			(+) syngeneic orthotopic models better reflect the natural liver microenvironment
Syngeneic/xenografts			(-) xenografts need immunocompromised mice
			(-) orthotopic tumor implants need surgical and imaging experience
Genetically engineered mouse models
Mouse embryo manipulation	++/+++	+++	(+) hepatocarcinogenesis can be analyzed stepwise
Cre-Lox recombination			(-) effects of manipulated gene(s) could have heterogeneous latency and genetic penetrance
Hydrodynamic injection
CRISPR-Cas9
Humanized mouse models
Immunologically humanized mice	+++	+++	(+) immunotherapeutical issues can be studied based on human cell lines in mice
Genetically humanized mice			(-) establishment difficult due to engraftment failure and development of stable stem cell-derived hepatocytes

HCC: Hepatocellular carcinoma.