Background: LncRNA PTCSC3 (PTCSC3) inhibits thyroid cancer cervical carcinoma and glioma, while its roles in gastric cancer are unknown. Studies have reported that HULC could serve as a potential biomarker for the diagnosis and prognosis of gastric cancer (GC). Our study aimed to investigate the potential interaction between PTCSC3 and HULC in gastric cancer. Methods: This study enrolled 77 gastric cancer patients at the First Affiliated Hospital of Anhui Medical University from January 2016 to January 2018. RT-qPCR was performed to analyze gene expression levels. Cell transfections were carried out to evaluate gene interactions. Transwell assays and wound healing assays were used to analyze the effects of transfection on cell invasion and migration. Western blotting was also used to illustrate the possibility that lncRNA PTCSC3 and lncRNA HULC negatively affected each other through WNT signal path. Results: We showed that PTCSC3 was downregulated in tumor tissues of gastric cancer patients in comparison to that in adjacent healthy tissues, and an inverse correlation between the expression levels of PTCSC3 and AJCC stage was observed. LncRNA HULC (HULC) was upregulated in tumor and inversely correlated with PTCSC3 in tumor tissues. Overexpression of PTCSC3 mediated the inhibition of HULC, while overexpression of HULC also mediated the inhibition of PTCSC3. PTCSC3 inhibited, while HULC promoted invasion and migration of gastric cancer cells. In addition, overexpression of HULC attenuated the effects of overexpression of PTCSC3. However, overexpression of PTCSC3 showed no significant effects on cell proliferation. We also found that PTCSC3/HULC affected each other to regulate cell invasion and migration through the Wnt/β-catenin signaling. Conclusion: Therefore, overexpression of PTCSC3 inhibited the invasion and migration of gastric cancer cells, and the function of PTCSC3 is associated with HULC.